CHEBI:41500 Phenylbutyrate BDBM50480960 Phenylbutanoic acid
3-Phenylbutyrate BDBM36098 (R)-3-phenylbutyric acid
phosphatidyl glycerol CHEMBL507352 BDBM50292393
1,2-dioleoyl-sn-glycerol BDBM50307105 CHEMBL590047
Uridine-5'-alpha-glycerol-tetraphosphate CHEMBL482895 BDBM50271292
1,2-didecanoyl-sn-glycerol (1-decanoyloxy-3-hydroxypropan-2-yl) decanoate 1-(decanoyloxy)-3-hydroxypropan-2-yl decanoate didecanoyl glycerol BDBM20717
Octanoic acid 1-hydroxymethyl-2-octanoyloxy-ethyl ester 1,2-dioctanoyl-sn-glycerol CHEMBL55267 BDBM50015677 Octanoic acid 1-hydroxymethyl-2-octanoyloxy-ethyl ester(diC8) (S)-1-hydroxymethyl-2-octanoyloxy-ethyl ester 1,2-Dioctanoyl glycerol
BDBM50303334 Diphosphoric Acid 1-r-Glycerol Ester 2-(Uridine-5'-yl)ester,di ammonium Salt
BDBM50303335 Diphosphoric Acid 1-beta-Glycerol Ester 2-(Uridine-5'-yl)ester,bis-Triethylammonium Salt
1-Arachidonoylglycerol CHEMBL124426 1-Arachidonoyl-sn-glycerol BDBM50117249 (2S)-2,3-dihydroxypropyl (5Z,8Z,11Z,14Z)-icosa-5,8,11,14-tetraenoate
CHEMBL219892 (+/-)-3-O-[4-(4,5-dihydro-5-oxo-1,2,4-4H-oxadiazol-3-yl)phenyl]-1,2-O-di(4-phenylbutyl)glycerol BDBM50206907
2-arachidonoylglycerol (2-AG) CHEMBL122972 2-Arachidonoylmonoglycerol (2-AG) 1,3-dihydroxypropan-2-yl (5Z,8Z,11Z,14Z)-icosa-5,8,11,14-tetraenoate 2-arachidonyl-glycerol BDBM26144
Glycerol Guaiacolate Methphenoxydiol Robitussin Humabid Franolyn Chesty Glyceryl Guaiacolate Nirolex For Chesty Cough Decongestant Famel Liqufruta Amonidron BDBM50240098 Guaifenesin Gecolate Guaiphenesin Mucinex Tixylix Chesty Cough Guaiacol Glyceryl Ether
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- Bystrom, CE; Pettigrew, DW; Remington, S; Branchaud, BP ATP analogs with non-transferable groups in the position as inhibitors of glycerol kinase Bioorg Med Chem Lett 7: 2613-2616 (1997)
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- Smith, PW; Whittington, AR; Sollis, SL; Howes, PD; Taylor, NR Novel inhibitors of influenza sialidases related to zanamivir. Heterocyclic replacements of the glycerol sidechain Bioorg Med Chem Lett 7: 2239-2242 (1997)
- Schweitzer, BA; Loida, PJ; Thompson-Mize, RL; CaJacob, CA; Hegde, SG Design and synthesis of beta-carboxamido phosphonates as potent inhibitors of imidazole glycerol phosphate dehydratase. Bioorg Med Chem Lett 9: 2053-8 (1999)
- Schweitzer, BA; Loida, PJ; CaJacob, CA; Chott, RC; Collantes, EM; Hegde, SG; Mosier, PD; Profeta, S Discovery of imidazole glycerol phosphate dehydratase inhibitors through 3-D database searching. Bioorg Med Chem Lett 12: 1743-6 (2002)
- Parkkari, T; Myllym?ki, M; Savinainen, JR; Saario, SM; Castillo-Mel?ndez, JA; Laitinen, JT; Nevalainen, T; Koskinen, AM; J?rvinen, T Alpha-methylated derivatives of 2-arachidonoyl glycerol: synthesis, CB1 receptor activity, and enzymatic stability. Bioorg Med Chem Lett 16: 2437-40 (2006)
- Nelson, WL; Wennerstrom, JE; Dyer, DC; Engel, JE Absolute configuration of glycerol derivatives. 4. Synthesis and pharmacological activity of chiral 2-alkylaminomethylbenzodioxans, competitive alpha-adrenergic antagonists. J Med Chem 20: 880-5 (1977)
- Brindisi, M; Maramai, S; Gemma, S; Brogi, S; Grillo, A; Di Cesare Mannelli, L; Gabellieri, E; Lamponi, S; Saponara, S; Gorelli, B; Tedesco, D; Bonfiglio, T; Landry, C; Jung, KM; Armirotti, A; Luongo, L; Ligresti, A; Piscitelli, F; Bertucci, C; Dehouck, MP; Campiani, G; Maione, S; Ghelardini, C; Pittaluga, A; Piomelli, D; Di Marzo, V; Butini, S Development and Pharmacological Characterization of Selective Blockers of 2-Arachidonoyl Glycerol Degradation with Efficacy in Rodent Models of Multiple Sclerosis and Pain. J Med Chem 59: 2612-32 (2016)
- Brizzi, A; Cascio, MG; Frosini, M; Ligresti, A; Aiello, F; Biotti, I; Brizzi, V; Pertwee, RG; Corelli, F; Di Marzo, V Resorcinol-sn-glycerol derivatives: novel 2-arachidonoylglycerol mimetics endowed with high affinity and selectivity for cannabinoid type 1 receptor. J Med Chem 54: 8278-88 (2011)
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- Nelson, WL; Powell, ML; Dyer, DC Absolute configuration of glycerol derivatives. 7. Enantiomers of 2-[[[2-(2,6-dimethoxyphenoxy)ethyl]amino]methyl]-1,4-benzodioxane (WB-4101), a potent competitive alpha-adrenergic antagonist. J Med Chem 22: 1125-7 (1979)
- Nacro, K; Bienfait, B; Lewin, NE; Blumberg, PM; Marquez, VE Diacylglycerols with lipophilically equivalent branched acyl chains display high affinity for protein kinase C (PK-C). A direct measure of the effect of constraining the glycerol backbone in DAG lactones. Bioorg Med Chem Lett 10: 653-5 (2000)
- ChEMBL_1449476 Inhibition of human ABHD6 expressed in HEK293T cell membranes assessed as reduction in glycerol production using 2-arachidonoyl glycerol substrate
- ChEMBL_2151791 Inhibition of human MAGL expressed in HeLa cells using [glycerol-1, 3-3H]-oleoyl glycerol as substrate incubated for 1 hr
- ChEMBL_328025 Inhibition of 1-monooleoyl glycerol induced beta-hematin formation
- ChEBML_155132 Inhibition of 1-monooleoyl glycerol (MOG) induced beta-hematin formation
- ChEBML_72907 Tested for its binding affinity against glycerol kinase (ATP competitive inhibition)
- ChEBML_90659 Inhibitory concentration against imidazole glycerol phosphate dehydratase (IGPD) from Cryptococcus neoformans
- ChEMBL_1743308 Inhibition of Wistar rat MAGL using 2-monooleoyl[1,2,3-3H]glycerol as substrate
- ChEMBL_90659 Inhibitory concentration against imidazole glycerol phosphate dehydratase (IGPD) from Cryptococcus neoformans
- ChEMBL_90660 Binding affinity imidazole glycerol phosphate dehydratase (IGPD) obtained from Cryptococcus neoformans
- ChEMBL_1742451 Agonist activity at FFA2R in mouse mature adipocytes assessed as inhibition of isoproterenol-induced glycerol production
- ChEBML_1687002 Inhibition of MAGL from Wistar rat brain using 2-monooleoyl[1,2,3-H]glycerol as substrate
- ChEMBL_1538843 Inhibition of GPAT1 (unknown origin) by CPM assay using glycerol-3-phosphate and oleoyl-CoA as substrate
- ChEMBL_1687002 Inhibition of MAGL from Wistar rat brain using 2-monooleoyl[1,2,3-H]glycerol as substrate
- ChEMBL_162385 Inhibition of Protein kinase C of rat brain using phosphatidyl serine: di-acyl glycerol (2:1)
- ChEMBL_2029683 Inhibition of FAAH in rat brain homogenate using 2-arachidonoyl-[3H]-glycerol as substrate by scintillation counting method
- ChEBML_1693841 Inhibition of HSL in rat adipocytes assessed as reduction in lipolysis by measuring glycerol concentration incubated for 30 mins by spectrophotometric analysis
- ChEMBL_1515031 Inhibition of DGAT2 (unknown origin) using [1-14C]decanoyl-CoA and didecanoyl-sn-glycerol substrates incubated for 40 mins
- ChEMBL_1541257 Inhibition of recombinant human DGAT-1 using 1,2,di(cis-9-octadecenoyl)-sn-glycerol as substrate by Microbeta counter
- ChEMBL_479895 Inhibition of human DAGLalpha mediated sn-1-[14C]oleoyl-2-arachidonoyl-glycerol hydrolysis to 2-AG in COS cell
- ChEMBL_811231 Inhibition of rat brain cytosolic MAGL assessed as [3H]-2-arachidonoyl glycerol hydrolysis after 10 mins by liquid scintillation spectroscopy
- ChEMBL_1449471 Inhibition of human DAGLalpha expressed in HEK293T cell membranes assessed as reduction in hydrolysis of inhibition of [14C]-sn-1-oleoyl-2-arachidonoyl-glycerol
- ChEMBL_1541258 Inhibition of DGAT-1 in human Chang cells assessed as lipid level after 6 hrs in presence of substrate [14C]glycerol by HPLC analysis
- ChEMBL_1870511 Inhibition of recombinant human MGAT2 expressed in sf9 cells using 2-monooleoyl glycerol/[14C]-oleoyl CoA as substrate by microscintillation counting method
- ChEMBL_2153726 Inhibition of human MGL expressed in human HeLa cells assessed as amount of cleaved glycerol measured after 1 hrs by flow through assay
- ChEMBL_803191 Inhibition of DGAT1-mediated triglyceride synthesis in human HT-29 cells using [3H]glycerol as substrate after 6 hrs by beta counting
- ChEMBL_957844 Inhibition of human recombinant DGAT2 using dioleoyl-sn-glycerol and [14C]oleoyl coenzyme A as substrate after 30 mins by liquid scintillation counting
- Biological Assay The assay used to measure the in vitro activity of MGL is adapted from the assay used for another serine hydrolase (FAAH) described in Wilson et al., 2003 (A high-throughput-compatible assay for determining the activity of fatty acid amide hydrolase. Wilson S J, Lovenberg T W, Barbier A J. Anal Biochem. 2003 Jul. 15; 318(2):270-5). The assay consists of combining endogenously expressed MGL from HeLa cells with test compounds, adding [glycerol-1,3-3H]-oleoyl glycerol, incubating for one hour, and then measuring the amount of cleaved [1,3-3H]-glycerol that passes through an activated carbon filter. The amount of cleaved, tritiated glycerol passing through the carbon filter is proportional to the activity of the MGL enzyme in a particular well/test condition.
- ChEBML_39071 In vitro beta adrenergic receptor activity against beta-3 adrenergic receptor in rat epididymal fat pads by stimulation of glycerol release from adipocytes.
- ChEMBL_1363765 Inhibition of human DGAT2 expressed in Sf9 insect cells using 1,2-dioleoyl-sn-glycerol and [14C]-palmitoyl-CoA substrate by scintillation counting analysis
- ChEMBL_1363771 Inhibition of human DGAT1 expressed in Sf9 insect cells using 1,2-dioleoyl-sn-glycerol and [14C]-palmitoyl-CoA substrate by scintillation counting analysis
- ChEMBL_1363772 Inhibition of mouse DGAT1 expressed in Sf9 insect cells using 1,2-dioleoyl-sn-glycerol and [14C]-palmitoyl-CoA substrate by scintillation counting analysis
- ChEMBL_39071 In vitro beta adrenergic receptor activity against beta-3 adrenergic receptor in rat epididymal fat pads by stimulation of glycerol release from adipocytes.
- ChEMBL_810739 Inhibition of human recombinant DGAT1 in Chang cells using [14C]-glycerol as substrate assessed as decrease in triglycerides synthesis after 6 hrs by HPLC analysis
- ChEMBL_983078 Inhibition of pig brain tubulin assembly preincubated for 15 mins followed by GTP addition measured after 20 mins by spectrophotometric analysis in presence of glycerol
- ChEMBL_1498249 Inhibition of GPAT in BALB/c mouse mitochondria using 14C-labeled glycerol-3-phosphate and palmitoyl-CoA incubated for 10 mins by scintillation counting method
- ChEMBL_1870503 Inhibition of recombinant human MGAT2 using 2-monooleoyl glycerol/[1-14C]-oleoyl CoA as substrate after 30 mins by liquid scintillation counting method
- ChEMBL_804415 Inhibition of human endothelial lipase expressed using recombinant adenovirus using glycerol-tri[9,10(n)-3H]oleate after 1 hr by vesicle assay
- ChEMBL_804416 Inhibition of human lipoprotein lipase expressed using recombinant adenovirus using glycerol-tri[9,10(n)-3H]oleate after 1 hr by vesicle assay
- ChEMBL_973379 Inhibition of DGAT-1 in mouse liver microsomes using didecanoyl glycerol and [14C]decanoyl-CoA as substrate after 60 mins by liquid scintillation counting analysis
- In Vitro Activity Assay The assay used to measure the in vitro activity of MGL is adapted from the assay used for another serine hydrolase (FAAH) described in Wilson et al., 2003 (A high-throughput-compatible assay for determining the activity of fatty acid amide hydrolase. Wilson S J, Lovenberg T W, Barbier A J. Anal Biochem. 2003 Jul. 15; 318(2):270-5.). The assay consists of combining endogenously expressed MGL from HeLa cells with test compounds, adding [glycerol-1,3-3H]-oleoyl glycerol, incubating for one hour, and then measuring the amount of cleaved [1,3-3H]-glycerol that passes through an activated carbon filter. The amount of cleaved, tritiated glycerol passing through the carbon filter is proportional to the activity of the MGL enzyme in a particular well/test condition.
- ChEMBL_1513968 Inhibition of mouse DGAT1 incubated for 60 mins using didecanoyl glycerol and [14C]decanoyl-CoA substrate by liquid scintillation counting and luminometry based flash plate assay
- ChEMBL_1566098 Inhibition of human MAGL expressed in African green monkey COS cells using 2-arachidonoyl-[3H]-glycerol as substrate incubated for 20 mins by scintillation counting method
- ChEMBL_1922128 Inhibition of recombinant human DAGLalpha expressed in COS7 cells using [14C]-oleoyl-2-arachidonoyl-glycerol as substrate measured after 20 mins by beta-counting method
- ChEMBL_2118564 Inhibition of DGAT2 in human hepatocytes using [14C]-glycerol as substrate preincubated for 15 mins followed by substrate addition and measured after 3 hrs by thin layer chromatography
- ChEMBL_530430 Inhibition of human recombinant DAGLalpha mediated sn-1-[14C]oleoyl-2-arachidonoyl-glycerol hydrolysis to 2-AG overexpressed in COS cells after 20 mins
- ChEMBL_948536 Inhibition of human DGAT1 expressed in Sf9 cells using 1,2-dioleoyl-sn-glycerol and [14C]-palmitoyl-Co A substrates incubated for 2 hrs by scintillation counting method
- ChEMBL_957845 Inhibition of human recombinant DGAT1 expressed in Sf9 cells using dioleoyl-sn-glycerol and [14C]oleoyl coenzyme A as substrate after 30 mins by liquid scintillation counting
- ChEMBL_990217 Inhibition of human DGAT-1 expressed in insect Sf9 cell microsomes using 1,2-dioleoyl-sn-glycerol and [14C]-palmitoyl-CoA as substrate after 2 hrs
- ChEBML_1636270 Inhibition of recombinant human DAGLalpha expressed in HEK293T cell membranes overexpressing MAGL using natural substrate 1-stearoyl-2-arachidonoly-sn-glycerol by fluorescence based assay
- ChEMBL_1515029 Inhibition of MGAT2 (unknown origin) assessed as effect on incorporation of [1-14C]decanoyl moiety into DAG using [1-14C]decanoyl-CoA and 1-decanoyl-rac-glycerol as substrates
- ChEMBL_1515030 Inhibition of DGAT1 (unknown origin) assessed as effect on incorporation of [1-14C]decanoyl moiety into TG using [1-14C]decanoyl-CoA and 1,2-didecanoyl-sn-glycerol as substrates
- ChEMBL_1636270 Inhibition of recombinant human DAGLalpha expressed in HEK293T cell membranes overexpressing MAGL using natural substrate 1-stearoyl-2-arachidonoly-sn-glycerol by fluorescence based assay
- ChEMBL_1687004 Inhibition of recombinant human MAGL expressed in African green monkey COS7 cells using 2-arachidonoyl-[3H]-glycerol as substrate after 20 mins by scintillation counting analysis
- ChEMBL_2077555 Inhibition of MAGL in human U937 cells assessed as reduction in [3H]glycerol formation using [1,2,3-3H]2-OG as substrate incubated for 15 mins by liquid scintillation spectroscopy
- ChEMBL_907777 Inhibition of Escherichia coli imidazoleglycerol phosphate dehydratase using imidazole glycerol phosphate as substrate incubated for 30 min prior to substrate addition measured for 16 min by spectrophotometric analysis
- ChEMBL_957769 Inhibition of MGAT2 in mouse intestinal microsomes using 2-oleyl-sn-glycerol and [14C]-oleyl-coenzyme A as substrate after 10 to 15 mins by liquid scintillation counting analysis
- ChEMBL_957770 Inhibition of MGAT2 in human intestinal microsomes using 2-oleyl-sn-glycerol and [14C]-oleyl-coenzyme A as substrate after 10 to 15 mins by liquid scintillation counting analysis
- ChEMBL_1566097 Inhibition of recombinant C-terminal His6-tagged human MAGL expressed in Escherichia coli using 2-arachidonoyl-[3H]-glycerol as substrate incubated for 20 mins by scintillation counting method
- ChEMBL_973378 Inhibition of recombinant human DGAT-2 expressed in Hep3B cell lysate using didecanoyl glycerol and [14C]oleoyl-CoA as substrate after 120 mins by liquid scintillation counting analysis
- ChEMBL_973380 Inhibition of recombinant human DGAT-1 expressed in Hep3B cell lysate using didecanoyl glycerol and [14C]decanoyl-CoA as substrate after 60 mins by liquid scintillation counting analysis
- ChEMBL_1453719 Inhibition of mouse brain MAGL-mediated [glycerol-1,2,3-3H]-2-OG hydrolysis preincubated for 15 mins measured 15 mins post 2-OG addition by liquid scintillation counting
- ChEMBL_1515039 Inhibition of human MGAT3 expressed in HEK293 cells assessed as effect on incorporation of [1,3-14C] glycerol into TAG by TLC method in presence of DGAT1 inhibitor PF-04620110 and DGAT2 inhibitor PF-06424439
- ChEMBL_1513967 Inhibition of human DGAT1 expressed in human Hep3B cells incubated for 60 mins using didecanoyl glycerol and [14C]decanoyl-CoA substrate by liquid scintillation counting and luminometry based flash plate assay
- ChEMBL_1553496 Inhibition of human recombinant DAGLalpha expressed in African green monkey COS cells using sn-1-stearoyl-2-[14C]-arachidonoyl-glycerol as substrate incubated for 15 mins by beta counting analysis
- ChEMBL_1676273 Inhibition of human DGAT2 assessed as reduction in synthesis of triglycerol in human hepatocyte using [14C]glycerol as substrate preincubated for 20 mins followed by substrate addition measured after 3.5 hrs by TLC method
- ChEMBL_1910956 Inhibition of pig FLAG3-tagged DGKalpha expressed in African green monkey COS7 cells using 1,2-dioleoyl-sn-glycerol as substrate measured after 30 mins by ADP-Glo luminescence assay
- ChEMBL_2056357 Inhibition of MAGL in human U937 cells using [glycerol-1,2,3-3H]2-OG as substrate preincubated for 15 mins followed by substrate addition and measured after 15 mins by liquid scintillation spectroscopy
- ChEMBL_537915 Inhibition of human recombinant DAGL-alpha-mediated sn-1-[14C]oleoyl-2-arachidonoyl-glycerol hydrolysis to 2-AG overexpressed in african green monkey COS7 cell membrane by scintillation counting
- ChEMBL_957854 Inhibition of human recombinant MGAT3 expressed in insect cell membrane using 2-oleyl-sn-glycerol and [14C]-oleyl-coenzyme A as substrate after 10 to 15 mins by liquid scintillation counting analysis
- ChEMBL_957855 Inhibition of human recombinant MGAT1 expressed in insect cell membrane using 2-oleyl-sn-glycerol and [14C]-oleyl-coenzyme A as substrate after 10 to 15 mins by liquid scintillation counting analysis
- ChEMBL_957856 Inhibition of mouse recombinant MGAT2 expressed in insect cell membrane using 2-oleoyl-sn-glycerol and oleoyl coenzyme A as substrate after 40 mins by Ellmans assay based rapidfire LCMS analysis
- ChEMBL_957858 Inhibition of human recombinant MGAT2 expressed in insect cell membrane using 2-oleoyl-sn-glycerol and oleoyl coenzyme A as substrate after 40 mins by Ellmans assay based rapidfire LCMS analysis
- ChEBML_1693733 Inhibition of recombinant full length human DGAT1 expressed in Sf9 insect cells using 1,2-didecanoyl-sn-glycerol as substrate after 60 mins in presence of palmitoyl-1-14C coenzyme A by scintillation counting
- ChEMBL_1281078 Inhibition of rat kidney NADPH-dependent aldose reductase assessed as DL-glyceraldehyde conversion to glycerol preincubated for 20 mins followed by NADPH addition measured after 5 mins by UV-Visible spectrophotometric analysis
- ChEBML_1651523 Inhibition of human platelet cytosolic phospholipase alpha-2 using 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycerol as substrate after 60 mins by UV-HPLC method
- ChEMBL_1651523 Inhibition of human platelet cytosolic phospholipase alpha-2 using 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycerol as substrate after 60 mins by UV-HPLC method
- ChEMBL_1676272 Inhibition of human DGAT2 using [1-14C]decanoyl-CoA/1,2-didecanoyl-sn-glycerol as substrate preincubated for 120 mins followed by substrate addition measured after 40 mins by liquid scintillation counting method
- ChEMBL_976373 Inhibition of DGAT-1-mediated triglyceride synthesis in human HT-29 cells using [3H]-glycerol as substrate incubated for 1 hr prior to substrate addition measured after 5 hrs by scintillation counting analysis
- ChEMBL_1739430 Inhibition of MAGL in human U937 cells using 2-OG containing [glycerol-1,2,3-3H]AEA as substrate preincubated for 30 mins followed by substrate addition and measured after 15 mins by liquid scintillation spectroscopic method
- ChEMBL_1924054 Inhibition of human GST-tagged DAGLalpha expressed in HEK293F cell membranes using 1-stearoyl-2-arachidonoyl-sn-glycerol as substrate preincubated for 20 mins followed by substrate addition by enzyme coupled natural substrate assay
- ChEMBL_1515027 Inhibition of MGAT3 (unknown origin) assessed effect on incorporation of [1-14C]decanoyl moiety into triacylglycerol using [1-14C]decanoyl-CoA and 1,2-didecanoyl-sn-glycerol as substrates pre-incubated for 30 mins before substrate addition
- ChEMBL_1566109 Inhibition of recombinant C-terminal His6-tagged human MAGL expressed in Escherichia coli using 2-arachidonoyl-[3H]-glycerol as substrate preincubated for 10 mins followed by substrate addition measured after 20 mins by scintillation counting method
- ChEMBL_1514730 Inhibition of human ABHD6 expressed in HEK293 cells assessed as reduction in glycerol production from 1-AG hydrolysis pre-incubated for 30 mins before 1-AG substrate addition and measured 90 mins post substrate addition by fluorescence method
- Spectral Binding Titrations Ligand binidng to CYP3A4 was monitored in 50 mM phosphate (pH 7.4) containing 20% glycerol and 1 mM DTT. The protein was titrated with small aliquots of DMSO solutions of GS4, GS5, GS6, GS7, or GS8 with the final solvent concentration < 2%.
- In Vitro FlashPlate Assay DGAT-1 activity was characterized by catalyzing the transfer of the radiolabeled decanoyl group onto the syn-3 position of didecanoyl glycerol. The resultant radiolabeled tridecanoyl glycerol (tricaprin) preferentially binds to the hydrophobic coating on the phospholipid FlashPlate, and radioactivity was measured in the TopCount Plate Reader. Various concentrations (0.0001 uM to 10 uM) of test compounds were added to individual wells prior to the addition of membranes. The potencies of DGAT-1 inhibition for the compounds were determined by calculating the IC50 values defined as the inhibitor concentration from the sigmoidal dose response curve at which the enzyme activity was inhibited 50%.
- Inhibition Assay The in vitro inhibitory activity of compounds against human MOGAT-2 is evaluated in this assay. MOGAT-2 transfers an oleoyl group to monooleoyl-glycerol (MAG) from oleoyl-CoA to form dioleoyl-glycerol (DAG) in the intestinal triglyceride resynthesis pathway. The assay takes advantage of Microscint E extraction, which extracts hydrophobic molecules selectively over hydrophilic ones to separate the 14C-oleoyl-CoA from 14C-DAG.Genetically engineered insect SF9 cells express human MOGAT-2. Prepare the cell lysate in 20 mM of NaCl with protease inhibitor (Roche Cat#11873580001). Homogenize the SF9 cells expressing human MOGAT-2 at 15,000 rpm for 20x2 seconds (PT-3100 Polytrone). Centrifuge the homogenate at 1000 g for 10 minutes at 4 C. Collect the supernatant into a separate tube for protein quantification and activity testing. Purify the glycerol monooleate substrate (Spectrum Chemical, CAS#25496-72-4) chromatographically.
- ChEMBL_1924055 Inhibition of full length V5 tagged human DAGLalpha expressed in African green monkey COS7 cells using sn-1-stearoyl-[14C]-arachidonoyl-glycerol as substrate preincubated for 15 mins followed by substrate addition measured after 30 mins by radiometric natural substrate assay
- ChEMBL_1924056 Inhibition of full length 3' FLAG-tagged mouse DAGLbeta expressed in African green monkey COS7 cells using sn-1-stearoyl-[14C]-arachidonoyl-glycerol as substrate preincubated for 15 mins followed by substrate addition measured after 30 mins by radiometric natural substrate assay
- Spectral Binding Assay The buffer contained 50 mM HEPES (pH 7.5), 10% glycerol, and 100 mM NaCl, containing 1 mM imidazole. The spectral shift was monitored for a few minutes in room temperature after each addition of increasing amounts of inhibitors to 5-6 μM protein.
- Isothermal Titration Calorimetry (ITC) An aqueous solution of the fragment to be tested (1 mM) was prepared containing NaCl (300 mM), Tris.HCl (20 mM, pH = 8.0), d6-DMSO (10% v/v) and glycerol (to match the 10% v/v glycerol content in the EthR stock solution). A separate aqueous solution of EthR (50 μM) containing NaCl (300 mM), Tris.HCl (20 mM, pH = 8.0) and DMSO-d6 (10% v/v) was prepared and placed in the sample cell of a MicroCal iTC200 microcalorimeter (GE Healthcare). The fragment solution was then titrated to the EthR solution over 19 or 39 injections (first injection of 0.4 μl and subsequent injections of 2.0 μL or 1.0 μL).
- DGAT Enzyme Inhibition Assay The assay mixture contains test compound, membrane protein, and 1,2 dioleoyl-sn-glycerol in a 96-deep well plate. The reaction was started by adding substrate [14C]oleoyl coenzyme A and incubated. After the reaction was stopped, radioactive triolein product was separated into the organic heptane phase. DGAT activity was quantified by counting aliquots of the upper heptane layer by liquid scintillography.
- HDAC8 Inhibition Assay (spectrofluorometric titration) A fixed concentration of 1.5 µM was titrated with an increasing concentration of the respective inhibitor in protein storage buffer containing 50 mM Tris (pH 7.5), 100 mM NaCl, 3 mM MgCl2, 10% glycerol, and 1 mM tris(2-carboxyethyl)phosphine (TCEP). The fluorescence was measured at 340 nm after excitation at 295 nm.
- DNA Gyrase Supercoiling Inhibition Assay DNA gyrase supercoiling assays were carried out by mixing the compounds and the enzyme in a similar manner as above (EcTopI relaxation inhibition assay) but in a gyrase assay buffer (35 mM Tris-HCl, 24 mM KCl, 4 mM MgCl2, 2 mM DTT, 1.75 mM ATP, 5 mM spermidine, 0.1 mg/mL BSA, 6.5% glycerol at pH 7.5), followed by the addition of 300 ng of relaxed covalently closed circular DNA (New England Biolabs, Ipswich, Mass., USA) to a final reaction volume of 20 μL. The samples were incubated at 37° C. for 30 minutes before being terminated by the addition of a buffer containing 5% SDS, 0.25% bromophenol blue, and 25% glycerol. The reactions were then analyzed by agarose gel electrophoresis.
- Kinase Assay Typically frozen cells from 10 L of Tn5 cell culture were resuspended in Lysis Buffer 20 mM Tris-Cl, pH 7.5, 500 mM NaCl, 5% glycerol, 5 mM imidazole, 1 mM NaF, 0.1 ug/mL okadaic acid (OAA), 5 mM BME, 1 Complete protease inhibitor cocktail EDTA-free (20 tablets/1 L buffer, Roche Applied Sciences), benzonase (25 U/mL lysis buffer, EMD Biosciences) at a ratio of 1:10 v/v pellet to Lysis Buffer ratio, and mechanically lysed by douncing 20 strokes using a tight-fitting pestle. The lysate was centrifuged at 45,000 g for 30 minutes, and the supernatant was loaded onto a pre-equilibrated IMAC column (5 mL resin/100 mL lysate). The column was washed with 3-5 column volumes of Lysis Buffer, followed by a second wash of 3-5 column volumes with 20 mM Tris-Cl, pH 7.5, 500 mM NaCl, 5% glycerol, 40 mM imidazole, 1 mM NaF, 0.1 ug/mL OAA, 5 mM BME, 1 Complete protease inhibitor cocktail EDTA-free. Protein was eluted with 20 mM Tris-Cl, pH 7.5, 500 mM NaCl, 5% glycerol, 250 mM imidazole.
- MAO-A and MAO-B Assays MAO assays included luminogenic MAO substrate, reaction buffers, Luciferin Detection and the reconstitution buffer with esterase. Standard MAO reaction mixtures included microsome contained MAO-A (2 ug) or MAO-B (10 ug), 160 uM substrate for MAO-A or 16 uM substrate for MAO-B, MAO-A buffer (100 mM Hepes buffer, pH 7.5, 5% glycerol) or MAO-B buffer (100 mM Hepes, pH 7.5, 5% glycerol, 10% dimethyl sulfoxide) in a final volume of 30 ul. After 20 minutes of pre-incubation of the enzyme with compounds, the reaction was initiated by adding enzyme substrate and the reaction was allowed to proceed for 60 minutes. Reconstituted Luciferin Detection Reagent (30 ul) was then added is added to simultaneously stop the MAO reaction and convert the methyl ester derivative to luciferin and produce light. The amount of light produced is directly proportional to the activity of MAO.
- Jump dilution assay 10 μM saFabI, 15 μM inhibitor, and 500 μM NADPH were preincubated overnight at room temperature followed by a 1:200 dilution into reaction buffer (50 mM potassium phosphate, pH 7.5, 150 mM NaCl, 1 M potassium glutamate, 8 v/v % glycerol) containing 1.5 mM trans-2-butenoyl-CoA and 350 μM NADPH.
- Electrophoretic Mobility Shift Assays (EMSAs) E3330 or E3330-amide was preincubated with 2 μL of APE1 (reduced with 1.0 mM DTT for 10 min and then diluted to a concentration of 0.06 mM with 0.2 mM DTT in PBS) in an EMSA reaction buffer that consisted of 10 mM Tris (pH 7.5), 50 mM NaCl, 1 mM MgCl2, 1 mM EDTA, and 5% (v/v) glycerol in a total volume of 16 μL for 30 min.
- Equilibrium Dialysis Equilibrium dialysis was performed using purified recombinant CtBP proteins (10 μM) in binding buffer (25 mM Tris-Cl, 100 mM NaCl, 1 mM EDTA, 5% glycerol, 1 mM DTT) on one side of a 10-kDa molecular mass cutoff membrane with either [adenine-2,3-3H]NAD+ or [4-3H]NADH in varying concentrations from 12 nM to 50 μM at 4 °C for 48 h.
- Inhibition Assay The reaction mixture (1 mL, pH 7.4) contained 100mM triethanolamine, 10mM EDTA, 0.2mM NADH, 1mM glyceraldehyde 3-phosphate (GAP) and 0.9 units of α-glycerol phosphate dehydrogenase (α-GPDH). The reaction was initiated by addition of 5 ng/mL of the corresponding TIM or the corresponding TIM pre-incubated with the studied compounds. In these cases, inhibition assays, the enzymes were pre-incubated for 2 h at 37 °C with the studied compounds.
- Inhibition Assay MAO assays included luminogenic MAO substrate, reaction buffers, Luciferin Detection and the reconstitution buffer with eserase. Standard MAO reaction mixtures included microsome contained MAO-A (2 ug) or MAO-B (10 ug), 160 uM substrate for MAO-A or 16 uM substrate for MAO-B, MAO-A buffer (100 mM Hepes buffer, pH 7.5, 5% glycerol) or MAO-B buffer (100 mM Hepes, pH 7.5, 5% glycerol, 10% dimethyl sulfoxide) in a final volume of 30 ul. After 20 minutes of pre-incubation of the enzyme with compounds, the reaction was initiated by adding enzyme substrate and the reaction was allowed to proceed for 60 minutes. Reconstituted Luciferin Detection Reagent (30 ul) was then added is added to simultaneously stop the MAO reaction and convert the methyl ester derivative to luciferin and produce light. The amount of light produced is directly proportional to the activity of MAO. The mixtures were further incubated for 20 minutes and activity of the enzyme was determined using Perkin-Elmer Envision Reader.
- MAO-A and MAO-B Assay MAO assays included luminogenic MAO substrate, reaction buffers, Luciferin Detection and the reconstitution buffer with esterase. Standard MAO reaction mixtures included microsome contained MAO-A (2 ug) or MAO-B (10 ug), 160 uM substrate for MAO-A or 16 uM substrate for MAO-B, MAO-A buffer (100 mM Hepes buffer, pH 7.5, 5% glycerol) or MAO-B buffer (100 mM Hepes, pH 7.5, 5% glycerol, 10% dimethyl sulfoxide) in a final volume of 30 ul. After 20 minutes of pre-incubation of the enzyme with compounds, the reaction was initiated by adding enzyme substrate and the reaction was allowed to proceed for 60 minutes. Reconstituted Luciferin Detection Reagent (30 ul) was then added is added to simultaneously stop the MAO reaction and convert the methyl ester derivative to luciferin and produce light. The amount of light produced is directly proportional to the activity of MAO. The mixtures were further incubated for 20 minutes and activity of the enzyme was determined using Perkin-Elmer Envision Reader.
- Scintillation Proximity Assay (SPA) Human PDE4A3 coding sequence (amino acids 2 to 825 from the sequence with accession number NP_001104779) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include an N-terminal His6 affinity tag and a C-terminal FLAG affinity tag to aid in purification. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was batch bound to Ni-NTA agarose (GE Healthcare) and eluted with 250 mM imidazole. This eluate was diluted with FLAG buffer (50 mM Tris HCl pH 7.5, 100 mM NaCl, 5% glycerol, 1 mM TCEP with protease inhibitors) and batch bound to ant-FLAG M2 agarose (Sigma) overnight at 4° C. The agarose was packed into a column, washed with buffer and eluted with buffer containing elute using 250 μg/mL Flag-peptide. Fractions were analyzed using SDS-PAGE Coomassie blue staining and pooled based on purity. Pooled fractions were chromatographed on a S200 120 mL column (GE Healthcare) in 50 mM Tris HCl pH 7.5, 150 mM NaCl, 10% glycerol, 2 mM TCEP with protease inhibitors. PDE4A3 fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, dialyzed against 50 mM Tris HCl pH 7.5, 100 mM NaCl, 20% glycerol, 2 mM TCEP, frozen and stored at −80° C.
- Scintillation Proximity Assay (SPA) Human PDE4C1 coding sequence (amino acids 2 to 712 from the sequence with accession number NP_000914.2) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include an N-terminal His6 affinity tag and a C-terminal FLAG affinity tag to aid in purification. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was batch bound to Ni-NTA agarose (GE Healthcare) and eluted with 250 mM imidazole. This eluate was diluted with FLAG buffer (50 mM Tris HCl pH 7.5, 100 mM NaCl, 5% glycerol, 1 mM TCEP with protease inhibitors) and batch bound to anti-FLAG M2 agarose (Sigma) overnight at 4° C. The agarose was packed into a column, washed with buffer and eluted with buffer containing elute using 250 μg/mL Flag-peptide. Fractions were analyzed using SDS-PAGE Coomassie blue staining and pooled based on purity. Pooled fractions were chromatographed on a S200 120 mL column (GE Healthcare) in 50 mM Tris HCl pH 7.5, 150 mM NaCl, 10% glycerol, 2 mM TCEP with protease inhibitors. PDE4C1 fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, dialyzed against 50 mM Tris HCl pH 7.5, 100 mM NaCl, 20% glycerol, 2 mM TCEP, frozen and stored at −80° C.
- ADP Glo Assay The ATPase assay is performed according the following protocol: Purified enzyme (20 nM p97), substrate (20 uM ATP) and a dose titration of compounds are mixed in buffer (50 mM TRIS pH 7.5, 20 mM MgCl2, 0.02% TX-100, 1 mM DTT, 0.2% (v/v) glycerol) and incubated at 37 C. for 15 minutes. The reaction is terminated and the level of product generated is measured using the ADP Glo Assay Kit (Promega, Madison Wis.).
- FLT3 Kinase Assay FLT3 is obtained from Invitrogen in 50 mM Tris (pH7.5); 100 mM NaCl; 0.05 mM EDTA, 0.05% NP-40, 2 mM DTT; 50% Glycerol # PV3182; Lot 286671; sequence see below). The enzyme is diluted to 720 nM (35 μg/ml) in enzyme dilution buffer and 10 μl aliquots are stored at −80° C.The activity of FLT3 is measured using the Z′-LYTETM assay technology from Invitrogen (#PV3191)
- Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 hours with 1 mL of anti-FLAG resin (Sigma catalog # A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 μg/ml 3×FLAG peptide).
- Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 hours with 1 mL of anti-FLAG resin (Sigma catalog #A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 g/ml 3×FLAG peptide).
- Inhibition Kinetics Assay Kinetics were performed on a Cary 100 spectrophotometer (Varian) at 20 °C. Reaction velocities were measured by monitoring the oxidation of NAD(P)H to NAD(P)+ at 340 nm (ε = 6220 M^-1 cm^-1). For saFabI, the reaction mixture was identical to that described previously for progress curve experiments [Schiebel et al., Structure, 20:802-813]. For ecFabI, the final reaction mixture contained ecFabI (75 nM), trans-2-butenoyl-CoA (800 μM; Sigma and Advent Bio), NADH (300 μM; Sigma), NAD+ (400 μM; Sigma), and inhibitor (2 v/v%DMSO) in 50mM potassium phosphate, pH 7.5, 150 mM NaCl, 8 v/v % glycerol. For InhA, the final reaction mixture contained InhA (100 nM), trans-2-octenoyl-CoA (200 μM), NADH (250 μM), NAD+ (200 μM), and inhibitor (2 v/v%DMSO) in 30mM PIPES, pH 6.8, 150 mM NaCl, 1 mM EDTA, 8 v/v % glycerol.
- DGAT2 Enzymatic Activity Assay DGAT2 activity was determined by measuring the amount of enzymatic product triolein (1,2,3-Tri(cis-9-octadecenoyl)glycerol) using the membrane prep mentioned above. The assay was carried out in deep well 384 plates in a final volume of 40 μL at rt. The assay mixture contained the following: assay buffer (100 mM Tris.Cl, pH 7.0, 20 mM MgCl2, 5% ethanol), 25 μM of diolein, 10 μM of oleoyl-CoA and 10 ng/μL of DGAT2 membrane.
- Enzymatic Activity Assay DGAT2 activity was determined by measuring the amount of enzymatic product triolein (1,2,3-Tri(cis-9-octadecenoyl)glycerol) using the membrane prep mentioned above. The assay was carried out in deep well 384 plates in a final volume of 40 μL at room temperature. The assay mixture contained the following: assay buffer (100 mM Tris.Cl, pH 7.0, 20 mM MgCl2, 5% ethanol), 25 μM of diolein, 10 μM of oleoyl-CoA and 10 ng/μL of DGAT2 membrane.
- Enzymatic Activity Assay DGAT2 activity was determined by measuring the amount of enzymatic product triolein (1,2,3-Tri(cis-9-octadecenoyl)glycerol) using the membrane prep mentioned above. The assay was carried out in deep well 384 plates in a final volume of 40 μL at room temperature. The assay mixture contained the following: assay buffer (100 mM Tris·Cl, pH 7.0, 20 mM MgCl2, 5% ethanol), 25 μM of diolein, 10 μM of oleoyl-CoA and 10 ng/μL of DGAT2 membrane.
- Enzymatic Activity Assay DGAT2 activity was determined by measuring the amount of enzymatic product triolein (1,2,3-Tri(cis-9-octadecenoyl)glycerol) using the membrane prep mentioned above.The assay was carried out in deep well 384 plates in a final volume of 40 μL at room temperature. The assay mixture contained the following: assay buffer (100 mM Tris.Cl, pH 7.0, 20 mM MgCl2, 5% ethanol), 25 μM of diolein, 10 μM of oleoyl-CoA and 10 ng/μL of DGAT2 membrane.
- Enzymatic Assay Furin activity was measured in triplicate in wells of a 96-well plate in 0.2 ml 50 mM HEPES, pH 7.5, containing 1 mM CaCl2, 0.005% Brij-35 and 20% glycerol. Pyr-RTKR-AMC (25 μM) was used as a substrate. The concentration of furin in the reactions was 50 nM. The steady-state rate of substrate hydrolysis was monitored continuously (λex=360 nm and λem=465 nm) at 37° C. using a Spectramax Gemini EM fluorescent spectrophotometer (Molecular Devices).
- In Vitro cPLA2 Assay Assay for cPLA2 activity was performed by the use of sonicated vesicles of 1-palmitoyl-2-arachidonoyl-sn-glycerol-3-phosphorylcholine (100 μM) containing 100,000 cpm of 1-palmitoyl-2-[1 14C]arachidonoylsn-glycerol-3-phosphorylcholine in 100 mM Hepes, pH 7.5, 80 μM Ca2, 2 mM dithiothreitol, and 0.1 mg/ml BSA as described. Following a 35-mM incubation at 37° C., the reaction was terminated (derived from Wijkander et al). The lower phase was separated by thin layer chromatography, and the spot corresponding to free [1-14C]arachidonic acid was visualized by digital imaging and quantified with a PhosphorImager (Fuji Instruments). The source of cPLA2 enzyme was recombinant overexpression of the human gene for group IVa PLA2 in baculovirus insect cell expression system, as described in Abdullah et al. Wijkander, J., and Sundler, R. (1991) Eur. J. Biochem. 202, 873-880 Abdullah, K., et al. (1995) Human cytosolic phospholipase A2 expressed in insect cells is extensively phosphorylated on Ser-505. Biochim Biophys Acta. 1995 May 11; 1244(1):157-64.
- Inhibition Assay Preparation of rhACC1. Two liters of SF9 cells, infected with recombinant baculovirus containing full length human ACC1 cDNA, were suspended in ice-cold lysis buffer (25 mM Tris, pH 7.5; 150 mM NaCl; 10% glycerol; 5 mM imidazole (EMD Bioscience; Gibbstown, N.J.); 2 mM TCEP (BioVectra; Charlottetown, Canada); Benzonase nuclease (10000 U/100 g cell paste; Novagen; Madison, Wis.); EDTA-free protease inhibitor cocktail (1 tab/50 mL; Roche Diagnostics; Mannheim, Germany). Cells were lysed by 3 cycles of freeze-thaw and centrifuged at 40,000xg for 40 minutes (4 C.). Supernatant was directly loaded onto a HisTrap FF crude column (GE Healthcare; Piscataway, N.J.) and eluted with an imidazole gradient up to 0.5 M over 20 column volumes (CV). ACC1-containing fractions were pooled and diluted 1:5 with 25 mM Tris, pH 7.5, 2 mM TCEP, 10% glycerol and direct loaded onto a CaptoQ (GE Healthcare) column and eluted with an NaCl gradient up to 1 M over 20 CV's.
- DGAT2 enzymatic activity assay DGAT2 activity was determined by measuring the amount of enzymatic product 13Ci8-triolein (13C-l,2,3-Tri(cis-9-octadecenoyl)glycerol) using the membrane prep mentioned above. The assay was carried out in ABgene 384-well assay plates in a final volume of 25 pL at rt. The assay mixture contained the following: assay buffer (100 mM Tris•Cl, pH 7.0, 20 mM MgCl2, 5% ethanol), 25 pM of di olein, 5 μM of 13C oleoyl-CoA and 8 ng/pL of DGAT2 membrane.
- Topoisomerase IIα Relaxation Assay Relaxation of negatively supercoiled plasmid DNA by human topoisomerase IIα was assayed in 20 µL of reaction buffer (10 mM Tris-HCl, pH 7.9, 150 mM NaCl, 0.1% BSA, 0.1 mM spermidine, 5% glycerol and ATP) containing 250 ng of supercoiledpHOT1 plasmid DNA and 1 unit of enzyme. After incubation at 37 °C for 30 min, the reactions were terminated and analysed by agarose gel electrophoresis. The ethidium bromide-stained gel was photographed over UV light for densitometry analysis.
- Enzyme Immunoassay (EIA) Assay I. Assay Solutions a. Preparation of 0.1M K2HPO4/KH2PO4 buffer (pH 7.4) Prepare 0.1 M KH2PO4 from 1M KH2PO4 (Sigma, Cat# P-8709) Prepare 0.1 M K2HPO4 from powder of K2HPO4 (Fisher, BP363-500) Mix 0.1 M K2HPO4 with 0.1 M KH2PO4 to adjust pH to 7.4. b. Preparation of 0.5% γ-globulin Add 0.1 g of γ-globulin (Sigma, Cat# G-5009) to 20 mL 0.1 M K2HPO4/KH2PO4 buffer (pH 7.4) and make 1-mL/vial aliquots and store in −80° C. c. Preparation of 100 mM GSH Add 307 mg of GSH (Sigma, Cat# G-6529) to 10 mL 0.1 M K2HPO4/KH2PO4 buffer (pH 7.4) and store at −80° C. d. Preparation of Reaction buffer: 198 mL of 0.1M K2HPO4/KH2PO4 buffer (pH 7.4) 2 mM GSH Prepared from 100 mM GSH 0.4 g Glycerol 2 mL of 0.5% γ-globulin Add 0.4 g of glycerol and 2 mL of 0.5% γ-globulin to 198 mL of 0.1 M K2HPO4/KH2PO4 buffer (pH7.4).
- Hsp90 chaperone assay The Hsp90 chaperone assay was performed to measure the ability of HSP90 protein to refold the heat-denatured luciferase protein. HSP90 was first incubated with different concentrations of test compounds in denaturation buffer (25 mM Tris, pH7.5, 8 mM MgSO4, 0.01% bovine gamma globulin and 10% glycerol) at room temperature for 30 min. Luciferase protein was added to denaturation mix and incubated at 50° C. for 8 min. The final concentration of HSP90 and luciferase in denaturation mixture were 0.375 μM and 0.125 μM respectively. A 5 μl sample of the denatured mix was diluted into 25 μl of renaturation buffer (25 mM Tris, pH7.5, 8 mM MgSO4, 0.01% bovine gamma globulin and 10% glycerol, 0.5 mM ATP, 2 mM DTT, 5 mM KCl, 0.3 μM HSP70 and 0.15 μM HSP40). The renaturation reaction was incubated at room temperature for 150 min, followed by dilution of 10 μl of the renatured sample into 90 μl of luciferin reagent (Luclite, PerkinElmer Life Science). The mixture was incubated at dark for 5 min before reading the luminescence signal on a TopCount plate reader (PerkinElmer Life Science).
- In Vitro Assay The Hsp90 chaperone assay was performed to measure the ability of HSP90 protein to refold the heat-denatured luciferase protein. HSP90 was first incubated with different concentrations of test compounds in denaturation buffer (25 mM Tris, pH7.5, 8 mM MgSO4, 0.01% bovine gamma globulin and 10% glycerol) at room temperature for 30 min. Luciferase protein was added to denaturation mix and incubated at 50° C. for 8 min. The final concentration of HSP90 and luciferase in denaturation mixture were 0.375 μM and 0.125 μM respectively. A 5 μl sample of the denatured mix was diluted into 25 μl of renaturation buffer (25 mM Tris, pH7.5, 8 mM MgSO4, 0.01% bovine gamma globulin and 10% glycerol, 0.5 mM ATP, 2 mM DTT, 5 mM KCl, 0.3 μM HSP70 and 0.15 μM HSP40). The renaturation reaction was incubated at room temperature for 150 min, followed by dilution of 10 μl of the renatured sample into 90 μl of luciferin reagent (Luclite, PerkinElmer Life Science). The mixture was incubated at dark for 5 min before reading the luminescence signal on a TopCount plate reader (PerkinElmer Life Science).
- MAO-A and MAO-B Assays MAO assays included lumnuogenic MAO substrate, reaction buffers, Luciferin Detection and the reconstitution buffer with esterase. Standard MAO reaction mixtures included microsome contained MAO-A (2 ug) or MAO-B (10 ug), 160 uM substrate for MAO-A or 16 uM substrate for MAO-B, MAO-A buffer (100 mM Hepes buffer, pH 7.5, 5% glycerol) or MAO-B buffer (100 mM Hepes, pH 7.5, 5% glycerol, 10% dimethyl sulfoxide) in a final volume of 30 ul. After 20 minutes of pre-incubation of the enzyme with compounds, the reaction was initiated by adding enzyme substrate and the reaction was allowed to proceed for 60 minutes. Reconstituted Luciferin Detection Reagent (30 ul) was then added is added to simultaneously stop the MAO reaction and convert the methyl ester derivative to luciferin and produce light. The amount of light produced is directly proportional to the activity of MAO. The mixtures were further incubated for 20 minutes and activity of the enzyme was determined using Perkin-Elmer Envision Reader.Note: IC50 refers to the concentration of a compound that inhibits a reaction by 50%. In the case of competitive inhibition, IC50=2Ki when the substrate is present at the Km concentration, as per the relationship:Ki=IC50/[1+(substrate concentration/Km)].
- Biological Assay The in vitro assay to identify DGAT1 inhibitors uses human DGAT1 enzyme expressed in Sf9 insect cells prepared as microsomes. The reaction was initiated by the addition of the combined substrates 1,2-dioleoyl-sn-glycerol and [14C]-palmitoyl-CoA and incubated with test compounds and microsomal membranes for 2 hours at room temperature. The assay was stopped by adding 0.5 mg wheat germ agglutinin beads in assay buffer with 1% Brij-35 and 1% 3-cholamidopropyldimethyl-ammonio-1-propane sulfonate. Plates were sealed with TopSeal and incubated for 18 hours to allow the radioactive triglyceride product to come into proximity with the bead.
- Exogenous PldA Assay In brief, 6 nM purified PldA was incubated with liposomes containing 90 μM 1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol), 10 μM 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, and 2.5 μCi [3H]-DPPC for 10 min at 37 °C in buffer containing 50 mM HEPES, pH 7.5, 100 mM KCl, and 3 mM MgCl2. The reaction was quenched with 10% trichloroacetic acid and bovine serum albumin on ice. Protein and lipid were removed by centrifugation. Free [3H]-choline was measured by scintillation counting.
- Human Topoisomerase IIalpha Decatenation Inhibition Assay Human Topoisomerase IIα assays were carried out by adding the compounds to 185 ng of kinetoplast DNA (kDNA, from TopoGen) in the buffer supplied by the manufacturer before the addition of 2 U of the enzyme. The samples were incubated for 15 minutes at 37° C. before the addition of 4 μL of a stop buffer containing 5% sarkosyl, 0.25% bromophenol blue, and 25% glycerol. The reactions were then analyzed by electrophoresis in 1% agarose gels containing 0.5 g/mL ethidium bromide before being photographed under UV light.
- Tight-binding assay Kinetics were performed on a Cary 100 spectrophotometer (Varian) at 20° C. Reaction velocities were measured by monitoring the oxidation of NAD(P)H to NAD(P)+ at 340 nm (Figure US10071965-20180911-P00001=6220 M−1 cm−1). For saFabI, the reaction mixture was identical to that described previously for progress curve experiments (Schiebel et al. (2012). Structure 20:802-13). For ecFabI, the final reaction mixture contained ecFabI (75 nM), trans-2-butenoyl-CoA (800 μM; Sigma and Advent Bio), NADH (300 μM; Sigma), NAD+ (400 μM; Sigma), and inhibitor (2 v/v % DMSO) in 50 mM potassium phosphate, pH 7.5, 150 mM NaCl, 8 v/v % glycerol. For InhA, the final reaction mixture contained InhA (100 nM), trans-2-octenoyl-CoA (200 μM), NADH (250 μM), NAD+ (200 μM), and inhibitor (2 v/v % DMSO) in 30 mM PIPES, pH 6.8, 150 mM NaCl, 1 mM EDTA, 8 v/v % glycerol. The resulting curves were fit to the Morrison and Walsh integrated rate equation (Equation 1) (Morrison et al.
- FP Binding Assay Binding of compounds with PAD4 was detected by FP assay. PAD4 was diluted to 1 uM in assay buffer (100 mM HEPES, 50 mM NaCl, 1 mM DTT, 5% Glycerol and 1 mM CHAPS) and added to wells containing various concentration of compounds or DMSO vehicle (1%) in a 384 well black plate. 10 nM of fluorescein labelled probe (JPAD-00085) was added to the plate. Assay plate was incubated for 60 minutes at RT before measuring FP reading at FP module (λex 485/λem 535 nm) on Pherastar. IC50 was calculated using XL-fit software model 205.
- Human Topoisomerase I Relaxation Inhibition Assay Human topoisomerase I relaxation assays were carried out with 0.5 U of enzyme in reaction buffer supplied by the manufacturer. The enzyme was mixed with the indicated concentration of compound dissolved before 200 ng of supercoiled pBAD/Thio plasmid DNA was added in the same buffer, for a final volume of 20 μL. Following incubation at 37° C. for 30 minutes, the reactions were terminated with a buffer containing 5% SDS, 0.25% bromophenol blue, and 25% glycerol, and analyzed by agarose gel electrophoresis.Human topoisomerase I and topoisomerase IIα were purchased from TopoGen (Buena vista, CO, USA).
- Inhibition Assay A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.
- Calorimetric (ITC) Assay For standard ITC analysis of ligand binding, proteins were dialyzed overnight in 25 mm Hepes (pH 7.5), 100 mm NaCl, 5 mm ??-mercaptoethanol, and 5% glycerol at 4 °C. Ligands (i.e. AdoMet, AdoCys, pEA, and pCho) were prepared in the same buffer. AdoMet and AdoCys concentrations were determined spectrophotometrically (A260 nm; ?? = 15,400 m???1 cm???1) (19). ITC experiments were performed using a VP-ITC calorimeter (Microcal, Inc.). Injections (10 ul) of ligand were added to a sample solution containing protein using a computer-controlled 250-ul microsyringe at intervals of 5???6 min.
- Fluorescence Resonance Energy Transfer (FRET)-Based Assay The assay was performed with plasmepsin-II/cathepsin D (1.2 nM) and substrate (malaria FRET-1; 1.0 μM) in 0.1 M sodium acetate buffer pH 5, containing 10% glycerol and 0.01% Tween 20. The hydrazide and hydrazine compounds dissolved in DMSO were added in the reaction mixture before the addition of substrate. The assays were performed with 5% final concentration of DMSO. The enzyme inhibition experiments were performed (in triplicates) in 96-well plate format and readings were obtained on a Perkin Elmer LS55 fluorescence spectrometer, Waltham, Massachusetts, with an excitation and emission wavelengths of 336 and 490 nm respectively.
- In Vitro TrkC Activity Human TrkC, catalytic domain [456-825(end) amino acids of accession number NP_002521.2] was expressed as N-terminal GST-fusion protein (69 kDa) using baculovirus expression system. GST-TRKC was purified by using glutathione sepharose chromatography and stored in 50 mM Tris-HCl, 150 mM NaCl, 0.05% Brij35, 1 mM DTT, 10% glycerol, pH7.5 at −80 C. The kinase activity was measured by off-chip mobility shift assay. The enzyme was incubated with fluorecence-labeled substrate, Srctide, in the presence of 100 uM of ATP (Mg/or Mn)/ATP). The phosphorylated and unphosphorylated substrates were separated and detected by LabChip¿ 3000.
- Inhibition Assay A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100
- Inhibition Assay Briefly, 2-10 nM of purified NS3 protease domains were pre-incubated at 37° C. for 10 minutes with 20 μM isogenic NS4A peptide cofactors (Sigma, St. Louis, Mo.), in 40% glycerol buffer with 50 mM HEPES pH 7.5 and 10 mM DTT. Compounds were diluted serially 1:3 in DMSO, incubated with the enzyme/cofactor mixture for 10 minutes and reactions were started by the addition of 2 μM RET S1 substrate (final concentration). Fluorescence increase was measured continuously over one hour using a Victor3 V fluorescence plate reader (Perkin Elmer, Waltham, Mass.).
- Inhibition Assay Human TrkC, catalytic domain [456-825(end) amino acids of accession number NP-002521.2] was expressed as N-terminal GST-fusion protein (69 kDa) using baculovirus expression system. GST-TRKC was purified by using glutathione sepharose chromatography and stored in 50 mM Tris-HCl, 150 mM NaCl, 0.05% Brij35, 1 mM DTT, 10% glycerol, pH7.5 at -80 C. The kinase activity was measured by off-chip mobility shift assay. The enzyme was incubated with fluorecence-labeled substrate, Srctide, in the presence of 100 uM of ATP (Mg/or Mn)/ATP). The phosphorylated and unphosphorylated substrates were separated and detected by LabChip 3000.
- Inhibition Kinetics Assay Slow-onset inhibition kinetics were monitored at 340 nm on a Cary 100 spectrophotometer (Varian) at 25 °C in 30 mM PIPES buffer (pH 8.0) containing 150 mM NaCl and 1.0 mM EDTA. The reactions were initiated by the addition of enzyme (8 nM) to a mixture containing glycerol [8% (v/v)], bovine serum albumin (0.1 mg/mL),DMSO [2% (v/v)], crot-CoA (750 μM), NADH (250 μM), NAD+ (200 μM), and inhibitor (0−8000 nM). All reactions were monitored until the steady state was reached, indicated by the linearity of the progress curve.
- Stimultaneous Relaxation Assay In simultaneous relaxation assay, CPT concentrations were 50 and 100 μM, whereas concentration of compounds were 50, 100 and 200 μM. Relaxation assay was carried out as described previously with LdTOPILS serially diluted in the relaxation buffer (25mM Tris-HCl pH 7.5, 5% glycerol, 0.5mM DTT, 10mM MgCl2, 2.5mM EDTA and 150 mg/ml BSA) supercoiled pBluescript (SKþ) DNA and 50mM KCl. The amount of supercoiled monomer DNA band fluorescence after ethidium bromide (EtBr) (0.5 mg/ml) staining was quantitated by using GEL Doc 2000 from Biorad (Hercules, CA, USA).
- TrkC Activity Human TrkC, catalytic domain [456-825 (end) amino acids of accession number NP_002521.2] was expressed as N-terminal GST-fusion protein (69 kDa) using baculovirus expression system. GST-TRKC was purified by using glutathione sepharose chromatography and stored in 50 mM Tris-HCl, 150 mM NaCl, 0.05% Brij35, 1 mM DTT, 10% glycerol, pH7.5 at −80 C. The kinase activity was measured by off-chip mobility shift assay. The enzyme was incubated with fluorecence-labeled substrate, Srctide, in the presence of 100 uM of ATP (Mg/or Mn)/ATP). The phosphorylated and unphosphorylated substrates were separated and detected by LabChip™ 3000.
- TrkC Activity Human TrkC, catalytic domain [456-825(end) amino acids of accession number NP_002521.2] was expressed as N-terminal GST-fusion protein (69 kDa) using baculovirus expression system. GST-TRKC was purified by using glutathione sepharose chromatography and stored in 50 mM Tris-HCl, 150 mM NaCl, 0.05% Brij35, 1 mM DTT, 10% glycerol, pH7.5 at −80 C. The kinase activity was measured by off-chip mobility shift assay. The enzyme was incubated with fluorecence-labeled substrate, Srctide, in the presence of 100 uM of ATP (Mg/or Mn)/ATP). The phosphorylated and unphosphorylated substrates were separated and detected by LabChip™3000.
- Biological Assays Human PDE4A3 coding sequence (amino acids 2 to 825 from the sequence with accession number NP_001104779) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include an N-terminal His6 affinity tag and a c-terminal FLAG affinity tag to aid in purification. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was batch bound to Ni-NTA agarose (GE Healthcare) and eluted with 250 mM imidazole. This eluate was diluted with FLAG buffer (50 mM Tris HCL pH 7.5, 100 mM NaCl, 5% Glycerol, 1 mM TCEP with protease inhibitors) and batch bound to ant-FLAG M2 agarose (Sigma) overnight at 4° C. The agarose was packed into a column, washed with buffer and eluted with buffer containing elute using 250 ug/ml Flag-peptide. Fractions were analyzed using SDS-PAGE Coomassie blue staining and pooled based on purity. Pooled fractions were chromatographed on a S200 120 ml column (GE Healthcare) in 50 mM Tris HCL pH 7.5, 150 mM NaCl, 10% Glycerol, 2 mM TCEP with protease inhibitors. PDE4A3 fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, dialyzed against 50 mM Tris HCL pH 7.5, 100 mM NaCl, 20% Glycerol, 2 mM TCEP, frozen and stored at −80° C.Human PDE4B1 coding sequence (amino acids 122 to 736 from the sequence with accession number Q07343) with the mutations resulting in the amino acid substitutions S134E, S654A, S659A, and S661A was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include a N-terminal His6 affinity tag to aid in purification followed by a thrombin cleavage site. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Insect cell paste was lysed and after centrifugation, the supernatant was chromatographed on Ni-NTA agarose (Qiagen) as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Ni-NTA agarose eluting fractions containing PDE4 were pooled, diluted with Q buffer A (20 mM Tris HCl pH 8, 5% glycerol, 1 mM TCEP) to reduce NaCl to −100 mM and loaded on a Source 15Q (GE Healthcare) column. After washing with Q buffer A/10% buffer B to baseline, PDE4D was eluted with a gradient from 10% to 60% of Buffer B (20 mM Tris HCl pH 8, 1 M NaCl, 5% glycerol, 1 mM TCEP). PDE4D fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, frozen and stored at −80° C.Human PDE4C1 coding sequence (amino acids 2 to 712 from the sequence with accession number NP_000914.2) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include an N-terminal His6 affinity tag and a c-terminal FLAG affinity tag to aid in purification. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was batch bound to Ni-NTA agarose (GE Healthcare) and eluted with 250 mM imidazole. This eluate was diluted with FLAG buffer (50 mM Tris HCL pH 7.5, 100 mM NaCl, 5% Glycerol, 1 mM TCEP with protease inhibitors) and batch bound to ant-FLAG M2 agarose (Sigma) overnight at 4° C. The agarose was packed into a column, washed with buffer and eluted with buffer containing elute using 250 ug/ml Flag-peptide. Fractions were analyzed using SDS-PAGE Coomassie blue staining and pooled based on purity.
- Scintillation Proximity Assay (SPA) A portion of the human PDE4D3 coding sequence (amino acids 50 to 672 from the sequence with accession number Q08499-2) was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include a C-terminal His6 affinity tag to aid in purification as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected and cells were harvested 72 hours after infection. Insect cell paste was lysed and after centrifugation, the supernatant was chromatographed on Ni-NTA agarose (Qiagen) as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Ni-NTA agarose eluting fractions containing PDE4 were pooled, diluted with Q Buffer A (50 mM Tris HCl pH 8, 4% glycerol, 100 mM NaCl, 1 mM TCEP, Protease inhibitors EDTA-free (Roche)) to reduce NaCl to ˜200 mM, and loaded on a Q Sepharose (GE Healthcare) column. After washing with Q buffer A to baseline, PDE4D was eluted with a gradient from 10% to 60% of Buffer B (50 mM Tris HCl pH 8, 1 M NaCl, 4% glycerol, 1 mM TCEP). PDE4D fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, frozen and stored at −80° C.
- Recombinant IDH1 Enzyme Assays All reactions were performed in standard enzyme reaction buffer (150 mM NaCl, 20 mM Tris-Cl, pH 7.5, 10% glycerol, 5 mM MgCl2 and 0.03% (w/v) bovine serum albumin). For determination of kinetic parameters, sufficient enzyme was added to give a linear reaction for 1 to 5 seconds. Reaction progress was monitored by observation of the reduction state of the cofactor at 340 nm in an SFM-400 stopped-flow spectrophotometer (BioLogic, Knoxville, Tenn.). Enzymatic constants were determined using curve fitting algorithms to standard kinetic models with the Sigmaplot software package (Systat Software, San Jose, Calif.). It is operated at 1×Km of NADPH.
- CYP19 Inhibition Assay The enzyme was obtained from the microsome fraction of fresh human placenta (St. Josephs Krankenhaus, Saarbrucken-Dudweiler, Germany) according to the method of Thompson and Siiteri (Thompson, E. A. & Siiteri, P. K., J. Biol. Chem. 249: 5364-5372 (1974)). The isolated microsomes were suspended in a mini mum volume of phosphate buffer (0.05 M; pH 7.4; 20% glycerol). In addition, DTT (10 mM) and EDTA (1 mM) were added to protect the enzyme from degradation reactions. The protein concentration was determined according to Lowry et al. (Lowry, O. H. et al., J. Biol. Chem. 193: 265-275 (1951)) and should be about 35 mg/ml after the processing.
- Electrophoretic Mobility Shift Assay (EMSA) DNA binding reaction (20 μL) was carried out in 1×DNA Binding Buffer (10 mM Tris, 40 mM NaCl, 1 mM EDTA, 4% glycerol) with 10 nM c-Rel protein and 0.5 ng phosphor-labeled CD28RE oligonucleotide for 10 minutes at room temperature in 96-well plates. Test compounds, in serial dilutions, were added into each well, and further incubated for 15 minutes before loading onto native 5% polyacrylamide gel. Electrophoresis proceeded for 2.5 hours at 160V. Radioactive signals were quantified using Phospho-Imager. IC50 of compounds of example 1 to 75 were determined by quantifying the intensity of Rel/NF-κB inhibition in EMSA using phospho-imager.
- In Vitro Csn5 Activity Assay Csn5 activity was measured using purified CSN complex and the fluorescent substrate OGNedd8–SCFSkp2, in which a unique cysteine engineered into Nedd8 was labeled with Oregon Green 488, after which the product was conjugated to SCFSkp2 as previously described [Duda et al., Cell, 134:995-1006]. Csn5-dependent cleavage of OGNedd8 from SCFSkp2 resulted in a decrease of fluorescence polarization. The assay was performed in buffer containing 40 mM Tris-HCl pH 7.5, 50 mM NaCl, 1 mM DTT, 0.01% Triton X-100, 1% glycerol, 25 mM trehalose and 15 μg/ml ovalbumin. Polarization data was collected with a PHERAstar plate reader using black low-volume 384-well plates.
- In Vitro Kinase Assay In vitro kinase assays with immunoprecipitated proteins (or recombinant CAK complexes) were performed as follows. Kinase reactions were performed in 25 μL of final volume of reaction buffer (50 mM Hepes, pH 7.5, 150 mM NaCl, 10 mM MgCl2, 5% glycerol, 25 μM ATP, and 10 μCi of [γ-32P]ATP). Each reaction contained 1 μg of RNAP II. Incubation was at 30° C. for 30-45 min. Reactions were terminated by addition of 5 μL of 5×SDS-PAGE sample buffer and incubated at 95° C. for 5 min. Reactions were analyzed by SDS-PAGE, and the dried gel was exposed to film or PhosphorImager plate.
- KinaseGlo Assay PKR: Commercially available recombinant human GST-PKR (1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Mass., USA).
- Preincubation Relaxation Assay In the preincubation assay, CPT concentrations were 50 and 100 μM, whereas various concentrations of compounds were 25, 50 and 100 μM. LdTOP1LS was preincubated with compounds 3a-d at different concentrations for 5 min at 37 °Cbefore the addition of substrate DNA. Relaxation assay was carried out as described previously with LdTOPILS serially diluted in the relaxation buffer (25mM Tris-HCl pH 7.5, 5% glycerol, 0.5mM DTT, 10mM MgCl2, 2.5mM EDTA and 150 mg/ml BSA) supercoiled pBluescript (SKþ) DNA and 50mM KCl. The amount of supercoiled monomer DNA band fluorescence after ethidium bromide (EtBr) (0.5 mg/ml) staining was quantitated by using GEL Doc 2000 from Biorad (Hercules, CA, USA).
- Scintillation Proximity Assay (SPA) Human PDE4B1 coding sequence (amino acids 122 to 736 from the sequence with accession number Q07343) with the mutations resulting in the amino acid substitutions S134E, S654A, S659A, and S661A was cloned into the baculovirus expression vector pFastBac (Invitrogen) engineered to include a N-terminal His6 affinity tag to aid in purification followed by a thrombin cleavage site. The recombinant Bacmid was isolated and used to transfect insect cells to generate a viral stock. To generate cell paste for purification, insect cells were infected with the virus stock and cells were harvested 72 hours after infection as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Insect cell paste was lysed and after centrifugation, the supernatant was chromatographed on Ni-NTA agarose (Qiagen) as described in Seeger, T. F. et al., Brain Research 985 (2003) 113-126. Ni-NTA agarose eluting fractions containing PDE4 were pooled, diluted with Q buffer A (20 mM Tris HCl pH 8, 5% glycerol, 1 mM TCEP) to reduce NaCl to ˜100 mM and loaded on a Source 15Q (GE Healthcare) column. After washing with Q buffer A/10% buffer B to baseline, PDE4D was eluted with a gradient from 10% to 60% of Buffer B (20 mM Tris HCl pH 8, 1 M NaCl, 5% glycerol, 1 mM TCEP). PDE4D fractions were analyzed by SDS-PAGE Coomassie blue staining, pooled based on purity, frozen and stored at −80° C.
- Assay of Inhibition of Mycobacterium tuberculosis RNA Polymerase Fluorescence-detected RNA polymerase assays with M. tuberculosis RNA polymerase were performed as in Example 21.1, using reaction mixtures containing (20 μl): 0-100 nM test compound, 75 nM M. tuberculosis RNA polymerase core enzyme, 300 nM M. tuberculosis σ A, 20 nM 384 bp DNA fragment containing the bacteriophage T4 N25 promoter, 100 μM ATP, 100 μM GTP, 100 μM UTP, 100 μM CTP, 40 mM Tris-HCl, pH 8.0, 80 mM NaCl, 5 mM MgCl2, 2.5 mM DTT, and 12.7% glycerol. IC50 is defined as the concentration of inhibitor resulting in 50% inhibition of RNA polymerase activity.
- Assay of Inhibition of Staphylococcus Aureus RNA Polymerase Fluorescence-detected RNA polymerase assays with S. aureus RNA polymerase were performed as in Example 21.1, using reaction mixtures containing (20 μl): 0-100 nM test compound, 75 nM S. aureus RNA polymerase core enzyme, 300 nM S. aureus σ A, 20 nM 384 bp DNA fragment containing the bacteriophage T4 N25 promoter, 100 μM ATP, 100 μM GTP, 100 μM UTP, 100 μM CTP, 40 mM Tris-HCl, pH 8.0, 80 mM NaCl, 5 mM MgCl2, 2.5 mM DTT, and 12.7% glycerol. IC50 is defined as the concentration of inhibitor resulting in 50% inhibition of RNA polymerase activity.
- Bla2 Activity Assay Bla2, in 50 mM MOPS and 30% (v/v) glycerol, was assayed for substrate activity by adding enzyme at a final concentration of 0.13 μg/mL to solutions ranging from 10-70 μM nitrocefin in 50 mM MOPS (pH 7.0) to a final volume of 1 mL in acrylic cuvettes at 25°C. To assess the ability of thiomaltol to inhibit the activity of Bla2, concentrations of thiomaltol ranging from 0-750 μM were incubated with enzyme for various time periods at the final reaction volume less the volume of nitrocefin necessary to initiate the reaction. Each mixture was incubated anywhere from 0-60 min in 10 min intervals before initiating reactions with nitrocefin (final concentration 36 μM). Reactions were monitored by observing the increase in absorbance at 485 nm and were performed in triplicate.
- DENV2 Protease Assay To measure the inhibitory activities of the compounds, the DENV2 NS2B-NS3 protease activities were measured in the presence of the compounds using Bz-Nle-Lys-Arg-Arg-AMC as a substrate. The enzyme concentration in the assay was 125 nM, and the substrate concentration was 20 µM in 10 mM Tris-HCl pH 8.5, 20% glycerol, and 1 mM CHAPS. The inhibitor concentrations were 100 µM for the first round and between 3.125 and 400 µM for the compounds 16 and 19 in the second round. Before adding the substrate, the enzyme and the inhibitors were incubated at 37 °C for 15 min. All reactions were performed in 96-well plates with a final volume of 50 µL per each wells using the FLx800 fluorescence microplate reader (excitation = 380 nm; emission = 460 nm).
- Enzymatic Assay The assay is done using an ADP-Glo Kinase Assay Kit (Promega, Catalog #V9102) according to the manufacturer's protocol with the following modifications. Briefly, hASK1 (0.25 nM) and MKK6 (300 nM) in a buffer (10 mM MOPS pH 7.0; 10 mM Mg-Acetate; 1 mM DTT; 0.025% NP-40; 0.05% BSA; 1.5% glycerol) are incubated with ASK1 inhibitors at varying concentrations ranging from 10.00 μM to 0.17 nM for 15 minutes, followed by incubation with ATP (100 μM) for 30 minutes at room temperature. ADP-Glo Reagent is added to terminate the kinase reaction and deplete the remaining ATP. The Kinase Detection Reagent is then added to convert ADP to ATP. The newly synthesized ATP is measured using a luciferase/luciferin reaction, and the luminescence determined by Envision (PerkinElmer).
- Enzymatic Assay The assay is done using an ADP-Glo™ Kinase Assay Kit (Promega, Catalog #V9102) according to the manufacturer's protocol with the following modifications. Briefly, hASK1 (0.25 nM) and MKK6 (300 nM) in a buffer (10 mM MOPS pH 7.0; 10 mM Mg-Acetate; 1 mM DTT; 0.025% NP-40; 0.05% BSA; 1.5% glycerol) are incubated with ASK1 inhibitors at varying concentrations ranging from 10.00 uM to 0.17 nM for 15 minutes, followed by incubation with ATP (100 uM) for 30 minutes at room temperature. ADP-Glo™ Reagent is added to terminate the kinase reaction and deplete the remaining ATP. The Kinase Detection Reagent is then added to convert ADP to ATP. The newly synthesized ATP is measured using a luciferase/luciferin reaction, and the luminescence determined by Envision (PerkinElmer).
- HTRF FRET Assay Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 μl are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window.
- HTRF FRET Assay Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window.
- In vitro IRAK-1 and IRAK-4 Assay Purified recombinant IRAK-4 protein was incubated with 250 uM synthetic peptide(KKARFSRFAGSSPSQSSMVAR) in 30 ul of kinase buffer including (20 mM MOPS pH7.2, 25 mM beta glycerol phosphate, 5 mM EGTA, 1 mM sodium orthovanadate, 1 mM DTT, 50 uM ATP, 20 mM MgCl2, 10 uCi gamma-33P, 0.1% BSA) for the indicated time. For purified recombinant IRAK-1 protein kinase assay, 50 uM ATP was used. A 25 ul aliquot of the reaction mixture was transferred on to p81 phosphocellulose squares (Upstate Biotechnology, Lake Placid, N.Y.). The assay squares were washed three times with 0.75% phosphoric acid and once with acetone. Enzyme activity was measured by determining the bound radioactivity by liquid scintillation counting.
- Inhibition Activity Assay MAO-A: The MAO-A inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100
- Inhibition Assay The inhibition of full-length hepatitis C NS3 protease enzyme was measured essentially as described in Poliakov, 2002 Prot Expression & Purification 25 363 371. Briefly, the hydrolysis of a depsipeptide substrate, Ac-DED(Edans)EEAbu[COO]ASK(Dabcyl)-NH2 (AnaSpec, San Jose, USA), was measured spectrofluorometrically in the presence of a peptide cofactor, KKGSVVIVGRIVLSGK (Ake Engstrom, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden). [Landro, 1997 #Biochem 36 9340-9348]. The enzyme (1 nM) was incubated in 50 mM HEPES, pH 7.5, 10 mM DTT, 40% glycerol, 0.1% n-octyl-D-glucoside, with 25 μM NS4A cofactor and inhibitor at 30 C. for 10 min, whereupon the reaction was initiated by addition of 0.5 μM substrate. Inhibitors were dissolved in DMSO, sonicated for 30 sec. and vortexed.
- Inhibition Assay To test for enzyme inhibition, the hemoglobin capture assay was used to measure nitric oxide production. The assay was performed at 37° C. in HEPES buffer (100 mM, with 10% glycerol, pH 7.4) in the presence of 10 μM L-arginine. Also included were 100 μM NADPH, 0.83 mM CaCl2, approximately 320 units/mL of calmodulin, 10 μM tetrahydrobiopterin, and human oxyhemoglobin (3 μM). For iNOS, CaCl2 and calmodulin were omitted and replaced with HEPES buffer (as neither are required for activation of iNOS). This assay was performed in 96-well plates using a Synergy 4 BioTek hybrid reader, and the dispensing of NOS enzyme and hemoglobin were automated; after 30 sec (maximum delay), NO production was read by monitoring the absorbance at 401 nm (resulting from the conversion of oxyhemoglobin to methemoglobin).
- MAO-A Inhibition Assay A test compound dissolved in 4% DMSO was added by 12.5 μL to 25 μL reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing 400 ng of MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 10 min. MAO substrate (Promega KK) (160 μM) was added by 12.5 μL to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate(%)=(1−(test compound count−blank)÷(control−blank))×100
- PKR KinaseGlo Assay Commercially available recombinant human GST-PKR (SignalChem, Canada; 1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Massachusetts, USA).
- Scintillation Proximity Assay SphK activity was measured by a scintillation proximity assay as previously described [1], the disclosure of which is incorporated herein. Briefly, recombinant SphK1 or SphK2 were expressed in Sf9 insect cells, crude homogenates were prepared and incubated in 96 well FlashPlates (Perkin-Elmer) in a buffer containing D-erythro-sphingosine and γ-[33P]ATP. The [33P]S1P product, which adheres to the plate wall, was quantified by scintillation counting. To assay ceramide kinase or diacylglycerol kinases, the recombinant proteins were incubated with γ-[32P]ATP and substrate (C6 ceramide or 1-Ohexadecyl-2-acetyl-sn-glycerol, respectively) and the lipid product, after recovery by organic extraction, was resolved by thin layer chromatography, detected by autoradiography, and quantified by liquid scintillation counting. These assays were performed with and without a fixed concentration of inhibitor and its effect on KM and Vmax determined.
- Scintillation Proximity Assay The assay method used was a scintillation proximity assay (SPA) (obtained from GE Healthcare, Product Code TRKQ7100), with [3H]-cGMP as the substrate (SPA manual, Amersham Biosciences). Purified human PDE7A and PDE7B (obtained from BPS Bioscience, San Diego, Calif.) were diluted and stored in a solution containing 25 mM Tris-Cl (pH 8.0), 100 mM NaCl, 0.05% Tween 20, 50% glycerol, and 3 mM DTT. PDE7 assays were carried out in the following reaction mixture (final concentrations): 50 mM Tris-Cl (pH 8.0), 8.3 mM MgCl2, 1.7 mM EGTA, 0.5 mg/ml BSA, 5% DMSO (except for OM056 which was in 2.5% DMSO) and 2 ng PDE7A or 0.2 ng PDE7B recombinant protein in a final volume of 0.1 mL.
- Syk Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 μM in storage buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 0.2% BSA; 0.01% CHAPS; 100 μM Na3VO4; 0.5 mM DTT, 10% glycerol) at −80° C. until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo® Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the kinase.
- Biochemical Assay A master mix minus Syk enzyme is prepared containing 1X Cell Signaling kinase buffer (25 mM Tris-HCl, pH 7.5, 5 mM beta-glycerophosphate, 2 mM dithiothreitol, 0.1 mM Na3VO4, 10 mM MgCl2), 0.5 μM Promega PTK Biotinylated peptide substrate 1, 0.01% casein, 0.01% Triton-X100, and 0.25% glycerol. A master mix plus Syk enzyme is prepared containing 1X Cell Signaling kinase buffer, 0.5 μM PTK Biotinylated peptide substrate 1, 0.01% casein, 0.01% Triton-X100, 0.25% glycerol and 0.4 ng/well Syk enzyme. Syk enzyme is purchased from Cell Signaling Technologies, expressed in baculovirus and is an N-terminally GST-tagged full length human wildtype Syk (accession number NM-00377).The Syk protein is purified in one step using glutathione-agarose. The purity of the final protein preparation is assessed by SDS-PAGE and Coomassie staining. A solution of 200 μM ATP is prepared in water and adjusted to pH 7.4 with 1N NaOH. A quantity of 1.25 μL of compounds in 5% DMSO is transferred to a 96-well ½ area Costar polystyrene plate.Compounds are tested singly and with an 11-point dose-responsive curve (starting concentration is 10-1 μM; 1:2 dilution). A quantity of 18.75 μL of master mix minus enzyme (as a negative control) and master mix plus enzyme is transferred to appropriate wells in 96-well ½ area Costar polystyrene plate. 5 μL of 200 μM ATP is added to that mixture in the 96-well ½ area Costar polystyrene plate for final ATP concentration of 40 μM.
- Aurora B Kinase Assay Recombinant human Aurora B (amino acids 1-344, clone number DU1773, Molecular weight 40.2 kDa, University of Dundee) was expressed as a fusion protein with an N-terminal His tag, affinity-purified and deep-frozen at a concentration of approx. 0.25-0.5 mg/ml in storage buffer (50 mM Tris-HCl pH 8; 25 mM Na-β-glycerophosphat; 0.1 mM EGTA; 150 mM NaCl; 0.03% Brij-35; 1 mM DTT and 10% glycerol) at −80° C. until use.The activity of the Aurora B kinase protein was determined using the ADP Glo® Luminescence Kinase test (Promega; V9103X). In this homogeneous test the amount of ADP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ADP still present and thus correlates with the activity of the protein kinase.
- Biochemical Assay The enzymatic activity of human HPK1 (MAP4K1) was monitored in a biochemical assay in the presence or absence of compounds and using a synthetic peptide substrate. An increase in phosphorylation of the peptide by HPK1 was indicative of its kinase activity.Recombinant HPK1 kinase domain produced via baculovirus infection of insect cells was obtained from Proteros (Proteros Biostructures #PR-0322) and was pre-activated in the presence of 2 mM ATP (Sigma-Aldrich, cat #GE27-2056-01) and 2 mM magnesium chloride for 16 hours at 4° C. The protein reaction mixture was then loaded to a desalting column (Thermo Fisher Scientific, Cat #89889) to remove excess ATP. HPK1 was eluted with buffer containing 20 mM Tris (2-Amino-2-(hydroxymethyl)propane-1,3-diol) pH 8.0, 150 mM NaCl, 2 mM dithiothreitol and 5% glycerol, and was frozen at −80° C. for later use. HPK1 dual phosphorylation was confirmed by mass spectrometry.
- Biological Assay CHO-K1 cells stably transfected with RORγt are maintained in MEM-EBS with 5% FBS, 1% penicillin streptomycin solution and 1 mg/mL G418. The cells are seeded at a density of 200000 cells/mL in white 96 well flat bottom plate. Post 16-18 hours incubation, the cells are transiently transfected with pFR Luc (50 ng/well DNA) for four hours. The cells are then treated with different doses of the test compounds in MEM EBS media with 10% FBS and 1% penicillin streptomycin. DMSO is used as vehicle control. After 18-20 hours treatment, the cells are lysed with lysis buffer (40 mM HEPES, 20 mM EGTA, 50 mM β-glycerophosphate, 10% glycerol and 1% Triton X-100 in distilled water) for 0.5 hour and luminescence is read using Tecan Safire reader at 1000 milli second integration time.
- CYP17 Total SPA Assay The assays were performed in U-bottom 384-well optiplates. The final assay volume was 15 ul prepared from 7.5 ul additions of microsomes (prepared as a high-speed pellet from homogenized HEK2 cells stably transfected with CYP17), substrates (3H Pregnenolone and NADPH) and test compounds in assay buffer (50 mM Potassium phosphate pH 7.2, 10% glycerol). The reaction was initiated by the combination of the microsomes and substrates in wells containing compound. The reaction was incubated at room temperature for 45 minutes and terminated by adding 7.5 ul of 0.2N HCl to each well. Following an incubation period of 10 minutes, anti-DHEA-coated SPA beads were added to the terminated reaction. The plate was sealed and incubated overnight with shaking at 4° C. The beads were allowed to settle in the plate for 1 hour and the plate read on a TOPCOUNT (Perkin-Elmer) plate reader.
- DNA Pol λ PEX Assay Pol λ reactions were made in a final volume of 20uL containing 50mM Tris-HCl pH 7.5, 1.5mM MgCl2, 5% (v/v) glycerol, 1mM DTT, 250nM purified recombinant pol λ, 150nM radioactive-labled primer F20H, 225nM template F33A, 0.1mg/mL BSA, 1uL compound solution with variable concentrations in DMSO (1uL DMSO for the solvent control). 5uL dNTP solution (15uM final) was added to initiate the reactions and positive controls. Reactions and controls were incubated for 30 min at 37 degrees Celsius and subsequently quenched using 45uL PAGE loading solution (80% (v/v) formamide, 20mM EDTA, 0.05% (w/v) bromophenol blue, 0.05% (w/v) xylene cyanol) per well. The reaction mixture was denatured for 5 min at 95 degrees Celsius and analyzed by 12% PAGE containing 8M urea.
- FRET-Based Assay The HCV NS3 protease functions have been extensively studied and are considered as potential targets for antiviral therapy: see for example the many references listed in the introductory section of this application. Therefore, the activity of the compounds of the invention as anti-HCV agents was assessed using a full length HCV NS3 protease.The protease activity of the full length NS3/4a was measured using a FRET-based assay utilizing a peptide substrate derived from the NS4A/B cleavage site (Anaspec) and labelled at one end with a quencher (QXL520) and at the other with a fluorophore (5-FAMsp). NS3/4a (produced in-house by literature methods) was incubated with test compounds and peptide substrate in 50 mM Tris pH8, 20 mM DTT, 1% CHAPS, 10% glycerol and 5% DMSO. The reaction was followed by monitoring the change in fluorescence on a Molecular Devices Gemini plate reader for 30 minutes at room temperature.
- Fluorescence Polarization Assay All fluorescence polarization experiments were conducted in 384-well, black, low volume, round-bottomed plates (Corning) using a BioTeck Synergy 2 plate reader (Winooski, VT). For binding experiments, to each well was added increasing amounts of protein and the 5-carboxyfluorescein-labeled Hsp70/90 C-terminal probe/tracer (20 nM). All wells had a final volume of 20 μl in the assay buffer (40 mM Tris-HCl, pH 7.4, 10% glycerol, 1 mM DTT). The plate was allowed to incubate at room temperature for 5 min toreach equilibrium. The polarization values in millipolarization units were measured at an excitation wavelength at 485 nm andan emission wavelength at 528 nm. An equilibrium binding isotherm was constructed by plotting the fluorescence polarization reading as a function of the protein concentration at a fixed concentration of tracer (20 nM).
- HIF-1alpha transactivation assays NIH3T3-EPO-luc cells were maintained at 37° C. in a humidified atmosphere containing 5% CO2 in DMEM supplemented with 10% fetal calf serum (FBS), and 1% (v/v) penicillin/streptomycin. Deferoxamine (DFX) was purchased from Sigma-Aldrich (USA). Cells (1×104/well in 96-well plates) were seeded the day before the assay. The next day, the cells were stimulated with increasing concentrations of either Cannabidiol (CBD), VCE-004 or compounds II to X. After six hours of stimulation the cells were lysed in 25 mM Tris-phosphate pH 7.8, 8 mM MgCl2, 1 mM DTT, 1% Triton X-100, and 7% glycerol during 15 min at RT in a horizontal shaker. Luciferase activity was measured using a microplate luminometer (Berthold) following the instructions of the luciferase assay kit (Promega, Madison. Wis., USA).
- In Vitro Assay Briefly, bulk histones, histone peptides or nucleosomes are incubated with purified human recombinant KDM1A, in the histone demethylase activity (HDM) assay buffer 1 (50 mM Tris pH 8.5, 50 mM KCl, 5 mM MgCl, 0.5% BSA, and 5% glycerol) from 30 minutes to 4 hours at 37° C. A typical reaction is conducted in 100 microliters in which either 20 micrograms of purified bulk histones or 3 micrograms of modified histone peptides are used as substrates. Different amounts of KDM1A ranging from 1-20 micrograms are used in the reaction along with, as necessary, other co-factors such as FAD or CoREST, depending on the chosen substrate. The reaction mixture is analyzed by SDS-PAGE and Western blotting using histone methyl-specific antibodies or by formaldehyde formation assay to examine the removal and conversion of the methyl group to formaldehyde, or by mass spectrometry in the case of peptide substrates to identify the demethylated histone peptide.
- Inhibition Activity Assay MAO-B: The MAO-B inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100.
- Inhibition Assay  Assay buffer [20 mM HEPES (pH 7.4), 100 mM MgCl2 and 0.04% bovine serum albumin (BSA)] containing 500 uM of enzyme substrate (didecanoyl glycerol) and 7.5 uM radiolabeled acyl-CoA substrate ([14C]decanoyl-CoA) was added to each well of a phospholipid-coated radiometric assay plate. A small aliquot of cell lysate having human DGAT1 activity (5 ug/well) obtained in above, of human liver microsomes having human DGAT1 activity (5 ug/well), or of mouse liver microsomes having mouse DGAT1 activity (5 ug/well) was added to the assay plate to start the reaction, and the reaction was allowed to proceed for 60 minutes at 25° C. The reaction was terminated upon the addition of an equal volume (100 uL) of isopropanol. The plates were sealed, incubated overnight and counted the next morning on a liquid scintillation counter and luminometer.
- KinaseGlo Assay PKR: Commercially available recombinant human GST-PKR (SignalChem, Canada; 1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Mass., USA). The % inhibition for the compounds is calculated using ATP only (100% inhibition) and PKR+ATP (0% inhibition).
- RNA-Dependent RNA HCV NS5B (polymerase) Assay and IC50 Determination The reaction mixtures consisted of 50 mM Hepes-KOH, pH 7.5, 5 mM MgCl2, 5 mM DTT, 2% glycerol, 0.01% Triton® X-100, 0.5 uM polyA:U16 substrate, purified HCV RNA-dependent RNA polymerase, 10 μM UTP, and 32P-UTP (Perkin Elmer). The reaction mixtures incubated at 30° C. for 60 minutes, and then filtered through Zeta probe membrane (BioRad). The filter was washed with 5×SSC (75 mM sodium citrate, pH 7 and 750 mM NaCl), and the radiolabeled RNA products were quantitated by microbeta (Perkin Elmer). For IC50 determination, different concentrations of inhibitors were added to the polymerase reaction mixtures, and incubated at 37° C. for 60 minutes. IC50 values were determined using GraFit (Erithaus software).
- SPA Assay The assays were performed in U-bottom 384-well optiplates. The final assay volume was 15 μl prepared from 7.5 μl additions of microsomes (prepared as a high-speed pellet from homogenized HEK2 cells stably transfected with CYP17), substrates (3H-Pregnenolone and NADPH) and test compounds in assay buffer (50 mM Potassium phosphate pH 7.2, 10% glycerol). The reaction was initiated by the combination of the microsomes and substrates in wells containing compound. The reaction was incubated at room temperature for 45 minutes and terminated by adding 7.5 μl of 0.2N HCl to each well. Following an incubation period of 10 minutes, anti-DHEA-coated SPA beads were added to the terminated reaction. The plate was sealed and incubated overnight with shaking at 4° C. The beads were allowed to settle in the plate for 1 hour and the plate read on a TOPCOUNT® (Perkin-Elmer) plate reader.
- SPA assay The assays were performed in U-bottom 384-well optiplates. The final assay volume was 15 μl prepared from 7.5 μl additions of microsomes (prepared as a high-speed pellet from homogenized HEK2 cells stably transfected with CYP17), substrates (3H-Pregnenolone and NADPH) and test compounds in assay buffer (50 mM Potassium phosphate pH 7.2, 10% glycerol). The reaction was initiated by the combination of the microsomes and substrates in wells containing compound. The reaction was incubated at room temperature for 45 minutes and terminated by adding 7.5 μl of 0.2N HCl to each well. Following an incubation period of 10 minutes, anti-DHEA-coated SPA beads were added to the terminated reaction. The plate was sealed and incubated overnight with shaking at 4° C. The beads were allowed to settle in the plate for 1 hour and the plate read on a TOPCOUNT® (Perkin-Elmer) plate reader.
- RIPK1 HTRF Binding Assay A solution was prepared containing 0.2 nM Anti GST-Tb (Cisbio, 61GSTTLB), 90.6 nM probe and 1 nM His-GST-TVMV-hRIPK1(1-324) in FRET Buffer (20 mM HEPES, 10 mM MgCl2, 0.015% Brij-35, 4 mM DTT, 0.05 mg/mL BSA). Using Formulatrix Tempest, the detection antibody/enzyme/probe solution (2 mL) was dispensed into wells of a 1536 plate (Black Low Binding Polystyrene 1536 Plate (Corning, 3724)) containing 10 nL of compounds of interest at appropriate concentration in DMSO. The plate was incubated at rt for 1 h. FRET was measured using the EnVision plate reader (Excitation: 340 nM, Emission: 520 nM/495 nM). Total signal (0% inhibition) was calculated from wells containing 10 nL DMSO only. Blank signal (100% inhibition) calculated from wells containing 10 nL of 15 nM staurosporine and internal controls.Cloning and Baculovirus Expression of RIPK1 ConstructThe coding region of human RIPK1(1-324) flanked by NdeI site at 5′ end and stop codon TGA and XhoI site at 3′ end was codon optimized and gene synthesized at GenScript USA Inc. (Piscataway, N.J.) and subcloned into a modified pFastBacl vector (Invitrogen, Carlsbad, Calif.) with N-terminal His-GST-TVMV tag, to generate His-GST-TVMV-hRIPK1(1-324)-pFB. The fidelity of the synthetic fragment was confirmed by sequencing.Baculovirus was generated for the construct using the Bac-to-Bac baculovirus expression system (Invitrogen) according to the manufacturer's protocol. Briefly, recombinant bacmid was isolated from transformed DH10Bac E. coli competent cells (Invitrogen) and used to transfect Spodoptera frugiperda (Sf9) insect cells (Invitrogen). Baculovirus was harvested 72 hours post transfection and a virus stock was prepared by infecting fresh Sf9 cells at a 1/1000 (v/v) ratio for 66 hours.For large scale protein production, Sf9 cells (Expression System, Davis, Calif.) grown in ESF921 insect medium (Expression System) at 2×106 cells/ml were infected with virus stock at a 1/100 (v/v) ratio for 66 hours. The production was carried out either at a 10 L scale in a 22 L cellbag (GE Healthcare Bioscience, Pittsburgh, Pa.) or at a 20 L scale in a 50 L cellbag using WAVE-Bioreactor System 20/50 (GE Healthcare Bioscience). The infected cells were harvested by centrifugation at 2000 rpm for 20 min at 4° C. in a SORVALL® RC12BP centrifuge. The cell pellets was stored at −70° C. before protein was purified.Purification of His-GST-TVMV-hRIPK1(1-324)RIPK1 containing cell paste was resuspended in 50 mM Tris pH 7.5, 150 mM NaCl, 10 mM imidazole, 5% glycerol, 5 mM MgSO4, 1 mM TCEP, 25 U/ml Benzonase, and Complete Protease Inhibitor tablets (1/50 ml, Roche Diagnostics, Indianapolis, Ind.). The cells were lysed by nitrogen cavitation using an unstirred pressure vessel @ 525 PSI (Parr Instrument Company, Moline, Ill.). The suspension was clarified by centrifugation at 136,000×g for 40 min, at 4° C. The lysate was decanted from the pellet and passed through a 5 ml NiNTA Superflow cartridge (Qiagen, Valencia, Calif.) using an AKTA Pure (GE Healthcare). Column was eluted with 10 CV linear gradient into 50 mM Tris 7.5, 150 mM NaCl, 500 mM imidazole, 5% glycerol, 1 mM TCEP. Peak fractions were pooled and loaded directly onto 5 ml GSTrap 4B column (GE Healthcare). Column was washed with 50 mM Tris 7.0, 150 mM NaCl, 5% glycerol, 1 mM DTT and eluted in 10 CV linear gradient into 50 mM Tris 8.0, 150 mM NaCl, 20 mM reduced glutathione, 5% glycerol, 1 mM DTT. Fractions identified by SDS-PAGE as containing RIPK1 were pooled and concentrated using 30 kDa MWCO spin concentrators (Amicon Ultra-15, Millipore, Billerica, Mass.) and loaded onto a HiLoad 26/600 Superdex 200 column (GE Healthcare) equilibrated in 25 mM Tris 7.5, 150 mM NaCl, 2 mM TCEP, 5% glycerol. The RIPK1 protein eluted as a dimer off the SEC column.The yield was 8 mg/L with a purity >95% as determined by Coomassie staind SDS-PAGE gel analysis.
- RIPK1 HTRF Binding Assay A solution was prepared containing 0.2 nM Anti GST-Tb (Cisbio, 61GSTTLB), 90.6 nM probe and 1 nM His-GST-TVMV-hRIPKl (1-324) in FRET Buffer (20 mM HEPES, 10 mM MgC12, 0.015% Brij-35, 4mM DTT, 0.05 mg/mL BSA). Using Formulatrix Tempest, the detection antibody/enzyme/probe solution (2 mL) was dispensed into wells of a 1536 plate (Black Low Binding Polystyrene 1536 Plate (Corning, 3724)) containing 10 nL of compounds of interest at appropriate concentration in DMSO. The plate was incubated at rt for 1 h. FRET was measured using the EnVision plate reader (Excitation: 340 nM, Emission: 520 nM/495 nM). Total signal (0% inhibition) was calculated from wells containing 10 nL DMSO only. Blank signal (100% inhibition) calculated from wells containing 10 nL of 15 nM staurosporine and internal controls.Cloning and Baculovirus Expression of RIPK1 ConstructThe coding region of human RIPKl(l-324) flanked by Ndel site at 5' end and stop codon TGA and Xhol site at 3' end was codon optimized and gene synthesized at GenScript USA Inc. (Piscataway, NJ) and subcloned into a modified pFastBacl vector (Invitrogen, Carlsbad, CA) with N-terminal His-GST-TVMV tag, to generate His-GST-TVMV-hRIPKl (1-324)-pFB. The fidelity of the synthetic fragment was confirmed by sequencing.Baculovirus was generated for the construct using the Bac-to-Bac baculovirus expression system (Invitrogen) according to the manufacturer's protocol. Briefly, recombinant bacmid was isolated from transformed DHIOBac E.coli competent cells (Invitrogen) and used to transfect Spodoptera frugiperda (Sf9) insect cells (Invitrogen). Baculovirus was harvested 72 hours post transfection and a virus stock was prepared by infecting fresh Sf9 cells at a 1/1000 (v/v) ratio for 66 hours.For large scale protein production, Sf9 cells (Expression System, Davis, CA) grown in ESF921 insect medium (Expression System) at 2 x 106 cells/ml were infected with virus stock at a 1/100(v/v) ratio for 66 hours. The production was carried out either at a 10 L scale in a 22 L cellbag (GE Healthcare Bioscience, Pittsburgh, PA) or at a 20 L scale in a 50 L cellbag using WAVE-Bioreactor System 20/50 (GE Healthcare Bioscience). The infected cells were harvested by centrifugation at 2000 rpm for 20 min at 4 °C in a SORVALL® RC12BP centrifuge. The cell pellets was stored at -70 °C before protein was purified.Purification of His-GST-TVMV-hRIPKl(l-324)RIPK1 containing cell paste was resuspended in 50 mM Tris pH 7.5, 150 mM NaCl, 10 mM imidazole, 5% glycerol, 5 mM MgSCE, 1 mM TCEP, 25 U/ml Benzonase, and Complete Protease Inhibitor tablets (1/50 ml, Roche Diagnostics, Indianapolis, IN). The cells were lysed by nitrogen cavitation using an unstirred pressure vessel @ 525 PSI (Parr Instrument Company, Moline, IL). The suspension was clarified by centrifugation at 136,000 x g for 40 min, at 4 °C. The lysate was decanted from the pellet and passed through a 5 ml NiNTA Superflow cartridge (Qiagen, Valencia, CA) using an AKTA Pure (GE Healthcare). Column was eluted with 10 CV linear gradient into 50 mM Tris 7.5, 150 mM NaCl, 500 mM imidazole, 5% glycerol, 1 mM TCEP. Peak fractions were pooled and loaded directly onto 5 ml GSTrap 4B column (GE Healthcare). Column was washed with 50 mM Tris 7.0, 150 mM NaCl, 5% glycerol, 1 mM DTT and eluted in 10 CV linear gradient into 50 mM Tris 8.0, 150 mM NaCl, 20 mM reduced glutathione, 5% glycerol, 1 mM DTT. Fractions identified by SDS-PAGE as containing RIPK1 were pooled and concentrated using 30 kDa MWCO spin concentrators (Amicon Ultra-15, Millipore, Billerica, MA) and loaded onto a HiLoad 26/600 Superdex 200 column (GE Healthcare) equilibrated in 25 mM Tris 7.5, 150 mM NaCl, 2 mM TCEP, 5% glycerol. The RIPK1 protein eluted as a dimer off the SEC column.The yield was ~8 mg/L with a purity >95% as determined by Coomassie stain SDS-PAGE gel analysis.
- In Vitro Enzyme Assay ATR for use in the in vitro enzyme assay was obtained from HeLa nuclear extract (CIL Biotech, Mons, Belgium) by immunoprecipitation with rabbit polyclonal antiserum raised to amino acids 400-480 of ATR (Tibbetts R S et al, 1999, Genes Dev. 13:152-157) contained in the following buffer (25 mM HEPES (pH7.4), 2 mM MgCl2, 250 mM NaCl, 0.5 mM EDTA, 0.1 mM Na3V04, 10% v/v glycerol, and 0.01% v/v Tween 20). ATR-antibody complexes were isolated from nuclear extract by incubating with protein A-Sepharose beads (Sigma, #P3476) for 1 hour and then through centrifugation to recover the beads. In the well of a 96-well plate, 10 ATR-containing Sepharose beads were incubated with 1 μg of substrate glutathione S-transferase-p53N66 (NH2-terminal 66 amino acids of p53 fused to glutathione {circumflex over ( )}-transferase was expressed in E. coli) in ATR assay buffer (50 mM HEPES (pH 7.4), 150 mM NaCl, 6 mM MgCl2, 4 mM MnCl2, 0.1 mM Na3V04, 0.1 mM DTT, and 10% (v/v) glycerol) at 37° C. in the presence or absence of inhibitor. After 10 minutes with gentle shaking, ATP was added to a final concentration of 3 μM and the reaction continued at 37° C. for an additional 1 hour. The reaction was stopped by addition of IOOμí PBS and the reaction was transferred to a white opaque glutathione coated 96-well plate (NUNC #436033) and incubated overnight at 4° C. This plate was then washed with PBS/0.05%>(v/v) Tween 20, blotted dry, and analyzed by a standard ELISA (Enzyme-Linked Immunosorbent Assay) technique with a phospho-serine 15 p53 (16G78) antibody (Cell Signaling Technology, #9286).
- MGAT LCMS Assay The MGAT enzyme reactions were performed in Corning FALCON® 96-well polypropylene plates, in a total volume of 60 μL of 50 mM potassium phosphate buffer pH 7.4, containing a final concentration of 100 μM 2-oleoylglycerol, 15 μM oleoyl-coenzyme A and 0.0013 μg/μL human or mouse MGAT-2 or 0.0026 μg/μL rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 μL of ice cold methanol containing 1 μg/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters SYMMETRY C8, 50×2.1 mm column, was used for the chromatography of enzyme products. The buffer system consists of 0.1% formic acid in water with a mobile phase consisting 0.1% formic acid in methanol. The shallow gradient is 90-100% mobile phase in 0.2 min with a total run time of 2.3 min. The first 0.5 minutes of each injection was diverted to waste to eliminate the presence of phosphate buffer in the enzymatic reaction. The column was run at 0.6 mL/min and a temperature of 65° C. Mass spectrometry analysis of the samples was performed on a ThermoFisher Quantum Triple quad utilizing APCI (+) as the mode of ionization. Data was acquired in Single Ion Monitoring (SIM) mode analyzing Diolein=m/z 603.6 (PRODUCT) and 1,2-distearoyl-rac-glycerol (IS)=m/z 607.6. The ratio of Diolein to internal standard (Peak Area Ratio) is utilized to calculate IC50 values.
- MGAT LCMS Assay The MGAT enzyme reactions were performed in Corning FALCON® 96-well polypropylene plates, in a total volume of 60 μL of 50 mM potassium phosphate buffer pH 7.4, containing a final concentration of 100 μM 2-oleoylglycerol, 15 μM oleoyl-coenzyme A and 0.0013 μg/μL human or mouse MGAT-2 or 0.0026 μg/μL rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 μL of ice cold methanol containing 1 μg/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters SYMMETRY® C8, 50×2.1 mm column, was used for the chromatography of enzyme products. The buffer system consists of 0.1% formic acid in water with a mobile phase consisting 0.1% formic acid in methanol. The shallow gradient is 90-100% mobile phase in 0.2 min with a total run time of 2.3 min. The first 0.5 minutes of each injection was diverted to waste to eliminate the presence of Phosphate buffer in the enzymatic reaction. The column was run at 0.6 mL/min and a temperature of 65° C. Mass spectrometry analysis of the samples was performed on a ThermoFisher Quantum Triple quad utilizing APCI (+) as the mode of ionization. Data was acquired in Single Ion Monitoring (SIM) mode analyzing Diolein=m/z 603.6 (PRODUCT) and 1,2-distearoyl-rac-glycerol (IS)=m/z 607.6. The ratio of Diolein to internal standard (Peak Area Ratio) is utilized to calculate IC50 values.
- MGAT LCMS Assay The MGAT enzyme reactions were performed in Corning FALCON® 96-well polypropylene plates, in a total volume of 60 μL of 50 mM potassium phosphate buffer pH 7.4, containing a final concentration of 100 μM 2-oleoylglycerol, 15 μM oleoyl-coenzyme A and 0.0013 μg/L human or mouse MGAT-2 or 0.0026 μg/L rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 μL of ice cold methanol containing 1 μg/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters SYMMETRY C8, 50×2.1 mm column, was used for the chromatography of enzyme products. The buffer system consists of 0.1% formic acid in water with a mobile phase consisting 0.1% formic acid in methanol. The shallow gradient is 90-100% mobile phase in 0.2 min with a total run time of 2.3 min. The first 0.5 minutes of each injection was diverted to waste to eliminate the presence of Phosphate buffer in the enzymatic reaction. The column was run at 0.6 mL/min and a temperature of 65° C. Mass spectrometry analysis of the samples was performed on a ThermoFisher Quantum Triple quad utilizing APCI (+) as the mode of ionization. Data was acquired in Single Ion Monitoring (SIM) mode analyzing Diolein=m/z 603.6 (PRODUCT) and 1,2-distearoyl-rac-glycerol (IS)=m/z 607.6. The ratio of Diolein to internal standard (Peak Area Ratio) is utilized to calculate IC50 values.
- MGAT LCMS Assay The MGAT enzyme reactions were performed in Corning FALCON® 96-well polypropylene plates, in a total volume of 60 μL of 50 mM potassium phosphate buffer pH 7.4, containing a final concentration of 100 μM 2-oleoylglycerol, 15 μM oleoyl-coenzyme A and 0.0013 μg/L human or mouse MGAT-2 or 0.0026 μg/L rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 μL of ice cold methanol containing 1 μg/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters SYMMETRY® C8, 50×2.1 mm column, was used for the chromatography of enzyme products. The buffer system consists of 0.1% formic acid in water with a mobile phase consisting 0.1% formic acid in methanol. The shallow gradient is 90-100% mobile phase in 0.2 min with a total run time of 2.3 min. The first 0.5 minutes of each injection was diverted to waste to eliminate the presence of Phosphate buffer in the enzymatic reaction. The column was run at 0.6 mL/min and a temperature of 65° C. Mass spectrometry analysis of the samples was performed on a ThermoFisher Quantum Triple quad utilizing APCI (+) as the mode of ionization. Data was acquired in Single Ion Monitoring (SIM) mode analyzing Diolein=m/z 603.6 (PRODUCT) and 1,2-distearoyl-rac-glycerol (IS)=m/z 607.6. The ratio of Diolein to internal standard (Peak Area Ratio) is utilized to calculate IC50 values.
- Binding Assay Compound 2 was examined for its ability to bind human FLAP using a membrane-binding assay. The affinity of Compound 2 for human FLAP was assessed using membranes from human polymorphonuclear leukocytes and tritiated leukotriene synthesis inhibitor, 3H-3-[5-(pyrid-2-ylmethoxy)-3-tert-butylthio-1-benzyl-indol-2-yl]-2,2-dimethylpropionic acid, as a ligand. A non-limiting example of such a FLAP binding assay is as follows: Packed human polymorphonuclear cell pellets (1.8x109 cells) (Biological Speciality Corporation) were resuspended, lysed and 100,000 g membranes prepared as described (Charleson et al. Mol. Pharmacol, 41, 873-879, 1992). 100,000 g pelleted membranes were resuspended in Tris-Tween assay buffer (100 mM Tris HCl pH 7.4, 140 mM NaCl, 2 mM EDTA, 0.5 mM DTT, 5% glycerol, 0.05% Tween 20) to yield a protein concentration of 50-100 ug/mL.
- Binding Assay The method employed was adapted from the scientific literature and described in detail by Osbourn et al. (1993, Biochemistry, 32, 6229-6236). Recombinant human ERalpha and ERR proteins were purified from transfected Sf9-cells. The in vitro assays involved the use of either ERalpha or ERbeta proteins and [3H]E2, at a fixed concentration of 0.5 nM, as the labeled ligand. Recombinant human ERalpha or ERbeta proteins were dissolved in binding buffer (10 mM Tris-HCL, pH 7.5, 10% glycerol, 1 mM DTT, 1 mg/ml BSA) and duplicate aliquots were then incubated with [3H]E2 at a final concentration of 0.5 nM, together with a vehicle control (0.4% DMSO), or the same amount of vehicle containing increasing concentrations of unlabeled steroid ligands as competitors. After incubation for 2 h at 25 C., the unbound ligands were removed and the amounts of [3H]E2 bound to either ERalpha or ERbeta proteins were measured.
- Biochemical Assay The purpose of the CDK6/Cyclin D3 assay is to evaluate the inhibition (% inhibition, Kiapp and Ki values) in the presence of small molecule inhibitors by using a fluorescence based microfluidic mobility shift assay. CDK6/Cyclin D3 catalyses the production of ADP from ATP that accompanies the phosphoryl transfer to the substrate peptide 5-FAM-Dyrktide (5-FAM-RRRFRPASPLRGPPK) (SEQ ID NO:3). The mobility shift assay electrophoretically separates the fluorescently labelled peptides (substrate and phosphorylated product) following the kinase reaction. Both substrate and product are measured and the ratio of these values is used to generate % conversion of substrate to product by the LabChip EZ Reader. Typical reaction solutions contained 2% DMSO (±inhibitor), 2% glycerol, 10 mM MgCl2, 1 mM DTT, 3.5 mM ATP, 0.005% Tween 20 (TW-20), 3 μM 5-FAM-Dyrktide, 4 nM (active sites) activated CDK6/Cyclin D3 in 40 mM HEPES buffer at pH 7.5.
- CDK6/Cyclin D3 Mobility Shift Assay The purpose of the CDK6/Cyclin D3 assay is to evaluate the inhibition (% inhibition, Kiapp and Ki values) in the presence of small molecule inhibitors by using a fluorescence based microfluidic mobility shift assay. CDK6/Cyclin D3 catalyzes the production of ADP from ATP that accompanies the phosphoryl transfer to the substrate peptide 5-FAM-Dyrktide The mobility shift assay electrophoretically separates the fluorescently labeled peptides (substrate and phosphorylated product) following the kinase reaction. Both substrate and product are measured and the ratio of these values is used to generate % conversion of substrate to product by the LabChip EZ Reader. Typical reaction solutions contained 2% DMSO (±inhibitor), 2% glycerol, 10 mM MgCl2, 1 mM DTT, 3.5 mM ATP, 0.005% Tween 20 (TW-20), 3 μM 5-FAM-Dyrktide, 4 nM activated CDK6/Cyclin D3 in 40 mM HEPES buffer at pH 7.5.
- DNA Pol β PEX Assay Pol β reactions were made in a final volume of 20uL containing 50mM Tris-HCl pH 7.9, 20mM KCl, 5% (v/v) glycerol, 1mM DTT, 2mM MnCl2, 250nM purified recombinant pol β, 150nM radioactive-labeled primer F20H, 225nM template F33A, 0.1mg/mL BSA, 1uL compound solution with various concentrations in DMSO (1uL DMSO for the solvent control). 5uL dNTP (15uM final) was added to initiate the reactions and positive controls. Reactions and controls were incubated for 30 min at 37 degrees Celsius and subsequently quenched using 45uL PAGE loading solution (80% (v/v) formamide, 20mM EDTA, 0.05% (w/v) bromophenol blue, 0.05% (w/v) xylene cyanol) per well. The reaction mixture was denatured for 5 min at 95 degrees Celsius and analyzed by 12% PAGE containing 8M urea.
- E. coli Topoisomerase I Relaxation Activity Inhibition Assay The relaxation activity of E. coli topoisomerase I was assayed in a buffer containing 10 mM Tris-HCl, pH 8.0, 50 mM NaCl, 0.1 mg/mL gelatin, and 0.5 mM MgCl2. Half microliter from the appropriate stock solutions of compounds dissolved in the solvent (DMSO) or the solvent alone (control) was mixed with 9.5 μL of the reaction buffer containing 10 ng of enzyme before the addition of 10 μL of reaction buffer containing 200 ng of supercoiled pBAD/Thio plasmid DNA purified by cesium chloride gradient as substrate. Following incubation at 37° C. for 30 min, the reactions were terminated by the addition of 4 μL of a stop buffer (50% glycerol, 50 mM EDTA, and 0.5% (v/v) bromophenol blue), and analyzed by agarose gel electrophoresis. The gels were stained in ethidium bromide and photographed under UV light.
- Enzymatic assay The aim of this in vitro assay was to measure the inhibition of HCV NS3/4A protease complexes by the compounds of the present invention. This assay provides an indication of how effective compounds of the present invention would be in inhibiting HCV NS3/4A proteolytic activity. The inhibition of full-length hepatitis C NS3 protease enzyme was measured essentially as described in Poliakov, 2002 Prot Expression & Purification 25 363 371. Briefly, the hydrolysis of a depsipeptide substrate, Ac-DED(Edans)EEAbu-y-[COO]ASK(Dabcyl)-NH2 (AnaSpec, San Jose, USA), was measured spectrofluorometrically in the presence of a peptide cofactor, KKGSVVIVGRIVLSGK (Ake Engstrom, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden). [Landro, 1997 #Biochem 36 9340-9348]. The enzyme (1 nM) was incubated in 50 mM HEPES, pH 7.5, 10 mM DTT, 40% glycerol, 0.1% n-octyl-D-glucoside, with 25 uM NS4A cofactor and inhibitor at 30 C. for 10 min.
- Enzyme Inhibition Assay A reaction was performed on a 384-well plate (Greiner Bio One) using a reaction volume of 24 µL, and all the samples were diluted with an assay buffer (50 mM tris buffer, pH 7.4, 10% glycerol). 0.8 mM NADPH, 6 mM glucose 6-phosphate, 0.35 units/mL glucose 6-phosphate dehydrogenase (Sigma Chemical), and 3 mM magnesium chloride and a microsome fraction as an enzyme source were added to the plate, and a solution containing a test compound dissolved in a dimethyl sulfoxide/methanol solution was added at a final concentration of 0.1%. After the addition of the test compound, cortisone at a final concentration of 160 nM was added to start the reaction, and the reaction was performed at room temperature for 3 h. 25 µL of 100 mM carbenoxolone (Sigma Chemical) was added to terminate the reaction, and the amount of cortisol produced was measured with RUBYstar (BMG LABTECH JAPAN Ltd.) using a cortisol prototype kit (Cisbio International) according to the package insert.
- Fluorescence Polarization Assay SH2 domains were dialyzed into binding buffer (50 mM Hepes, pH 7.25, 150 mM NaCl, 0.01% Nonidet P-40, 5% glycerol) and a 30-μl volume serially diluted into pre-chilled 384-well low flange black flat bottom non-binding microplates (Corning) while on ice. 5 μl of 35 nM fluorescent peptide dissolved in binding buffer was added to each well (final concentration 5 nM), mixed 5 times by pipetting, and plates were incubated at 4 °C for 40 min. Fluorescence polarization experiments were performed with an Analyst AD (Molecular Devices, Sunnyvale, CA) spectrofluorimeter. Each well was excited using 485 nm light and emission was read at 530 nm. Fluorescence polarization was measured 1 mm from the bottom of each well with an integration time of 560 ms. All experiments were conducted in triplicate.
- HTRF FRET Assay Reagents: Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide.A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.
- HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3x the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 ul) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol.
- HTRF FRET Assay BACE1: Reagents: Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide.A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.
- In Vitro Enzyme Assay The three NOS isoforms, rat nNOS, murine iNOS and bovine eNOS were recombinant enzymes overexpressed in E. coli and purified as reported in the literature. (See, e.g., example 51 of the aforementioned incorporated '790 patent and the references cited therein.) The hemoglobin capture was used to measure nitric oxide production. (See, Hevel, J. M. and Marietta, M. A. Nitric Oxide Synthase Assays. Methods Enzymol. 1994, 133, 250-258.) Briefly, the assay was run at 37 C. in 100 mM HEPES buffer (10% glycerol; pH 7.4) in the presence of 10 uM L-arginine. The following NOS cofactors were also included in the assay: 100 uM NADPH, 10 uM tetrahydrobiopterin, 1 mM CaCl2, 11.6 ug/mL calmodulin and 3.0 uM oxyhemoglobin. For iNOS, calmodulin and CaCl2 were omitted. The assay was run in a high throughput manner, using the Synergry 4 by BioTek, at the Northwestern University HighThroughput Analysis Facility.
- Inhibition Assay 30 uM ATP: In a final reaction volume of 50 ul, recombinant PIM-1 (1 ng) was incubated with 12 mM MOPS pH 7.0, 0.4 mM EDTA, glycerol 1%, brij 35 0.002%, 2-mercaptoethanol 0.02%, BSA 0.2 mg/ml, 100 uM KKRNRTLTK (SEQ ID NO.: 5), 10 mM MgAcetate, 30 uM ATP, [γ-33P-ATP] (specific activity approx. 500 cpm/pmol), DMSO 4% and test inhibitor compound at the required concentration. The reaction was initiated by the addition of the Magnesium ATP mixture. After 40 min incubation at 23° C., the reactions were quenched by the addition of 100 ul 0.75% Phosphoric acid, and the labeled peptide collected by filtration through a phosphocellulose filter plate. The plate was washed 4 times with 0.075% phosphoric acid (100 ul per well) and then, after the addition of scintillation fluid (20 ul per well), the counts were measured by a scintillation counter.
- Inhibition Assay A mixture containing 100 mM MES-sodium hydroxide (pH 6.5), 1 mM magnesium acetate, 0.5 mM EGTA, 5 mM beta-mercaptoethanol, 0.02% Tween 20, 10% glycerol, 12 ug/ml P-GS1, 41.7 uM [gamma-32P] ATP (68 kBq/ml), bovine cerebral TPK1 and a compound shown in Table (a final mixture contained 1.7% DMSO deriving from a solution of a test compound prepared in the presence of 10% DMSO) was used as a reaction system. The phosphorylation was started by adding ATP, and the reaction was conducted at 25 C. for 2 hours, and then stopped by adding 21% perchloric acid on ice cooling. The reaction mixture was centrifuged at 12,000 rpm for 5 minutes and adsorbed on P81 paper (Whatmann), and then the paper was washed four times with 75 mM phosphoric acid, three times with water and once with acetone. The paper was dried, and the residual radioactivity was measured using a liquid scintillation counter. The results are shown in the table below.
- Inhibition Assay A mixture containing 100 mM MES-sodium hydroxide (pH 6.5), 1 mM magnesium acetate, 0.5 mM EGTA, 5 mM, .beta.-mercaptoethanol, 0.02% Tween 20, 10% glycerol, 12 .mu.g/ml P-GS1, 41.7 .mu.M [.gamma.-.sup.32P] ATP (68 kBq/ml), bovine cerebral TPK1 and a compound shown in Table (a final mixture contained 1.7% DMSO deriving from a solution of a test compound prepared in the presence of 10% DMSO) was used as a reaction system. The phosphorylation was started by adding ATP, and the reaction was conducted at 25.degree. C. for 2 hours, and then stopped by adding 21% perchloric acid on ice cooling. The reaction mixture was centrifuged at 12,000 rpm for 5 minutes and adsorbed on P81 paper (Whatmann), and then the paper was washed four times with 75 mM phosphoric acid, three times with water and once with acetone. The paper was dried, and the residual radioactivity was measured using a liquid scintillation counter. The results are shown in the table below.
- Inhibition Assay Preparation of rhACC2. Human ACC2 inhibition was measured using purified recombinant human ACC2 (hrACC2). Briefly, a full length Cytomax clone of ACC2 was purchased from Cambridge Bioscience Limited and was sequenced and subcloned into PCDNA5 FRT TO-TOPO (Invitrogen, Carlsbad, Calif.). The ACC2 was expressed in CHO cells by tetracycline induction and harvested in 5 liters of DMEM/F12 with glutamine, biotin, hygromycin and blasticidin with 1 ug/mL tetracycline (Invitrogen, Carlsbad, Calif.). The conditioned medium containing ACC2 was then applied to a Softlink Soft Release Avidin column (Promega, Madison, Wis.) and eluted with 5 mM biotin. 4 mgs of ACC2 were eluted at a concentration of 0.05 mg/mL (determined by A280) with an estimated purity of 95% (determined by A280). The purified ACC2 was dialyzed in 50 mM Tris, 200 mM NaCl, 4 mM DTT, 2 mM EDTA, and 5% glycerol. The pooled protein was frozen and stored at -80 C., with no loss of activity upon thawing.
- Inhibition Assay The TACE enzyme is an internal production (carried out according to the publication protein Eng Des Sel 2006, 19, 155-161) and is added so as to have a signal equivalent to 6 times the background noise in 2 h at 37° C. The reaction is carried out in 50 mM Tris buffered medium containing 4% glycerol, pH 7.4. The fluorescent substrate is MCA-Pro-Leu-Ala-Val-(Dpa)-Arg-Ser-Ser-Arg-NH2 (R&D systems, reference: ES003). The substrate is cleaved by the enzyme between the alanine and the valine, thus releasing a fluorescent peptide (excitation: 320 nm, emission: 420 nm). The substrate is used at 40 uM. The reaction is carried out in a final volume of 10 ul (4 ul inhibitor, 4 ul substrate, 2 ul enzyme) in a low volume 384-well plate (Corning reference: 3676). The plate is incubated at ambient temperature for 2 h, and then read by fluorescence on a Pherastar reader (BMG labtech).
- Inhibition Assay The inhibition of full-length hepatitis C NS3 protease enzyme was measured essentially as described in Poliakov, 2002 Prot Expression & Purification 25 363 371. Briefly, the hydrolysis of a depsipeptide substrate, Ac-DED(Edans)EEAbuψ[COO]ASK(Dabcyl)-NH2 (AnaSpec, San José, USA), was measured spectrofluorometrically in the presence of a peptide cofactor, KKGSVVIVGRIVLSGK (Åke Engström, Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden) (Landro, 1997 Biochem 36 9340-9348). The enzyme (1 nM) was incubated in 50 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) pH 7.5, 10 mM dithiothreitol, 40% glycerol, 0.1% n-octyl-D-glucoside, with 25 μM NS4A cofactor and inhibitor at 30° C. for 10 min, whereupon the reaction was initiated by addition of 0.5 μM substrate. Inhibitors were dissolved in DMSO, sonicated for 30 sec and vortexed. The solutions were stored at −20° C. between measurements.
- Inhibition Assay The method employed was adapted from the scientific literature and described in detail by Osboum et al. (1993, Biochemistry, 32, 6229-6236). Recombinant human ERalpha and ERbeta proteins were purified from transfected Sf9-cells. The in vitro assays involved the use of either ERalpha or ERbeta proteins and [3H]E2, at a fixed concentration of 0.5 nM, as the labeled ligand. Recombinant human ERalpha or ERbeta proteins were dissolved in binding buffer (10 mM Tris-HCL, pH 7.5, 10% glycerol, 1 mM DTT, 1 mg/ml BSA) and duplicate aliquots were then incubated with [3H]E2 at a final concentration of 0.5 nM, together with a vehicle control (0.4% DMSO), or the same amount of vehicle containing increasing concentrations of unlabeled steroid ligands as competitors. After incubation for 2 h at 25 C., the unbound ligands were removed and the amounts of [3H]E2 bound to either ERalpha or ERbeta proteins were measured.
- Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 uM in test buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; either 0.2% BSA or 0.2% HSA; 0.01% CHAPS; 100 uM Na3VO4; 0.5 mM DTT) and 10% glycerol at -80 C. until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the protein kinase.MethodThe test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM.
- Kinase Assay The assay reactions were performed in U-bottom 384-well plates. The final assay volume was 30 ul prepared from 15 ul additions of enzyme and substrates (fluoresceinated peptide and ATP) and test compounds in assay buffer (100 mM HEPES pH 7.4, 10 mM MgCl2,25 mM beta-glycerol phosphate 0.015% Brij35 and 4 mM DTT). The reaction was initiated by the combination of GST-JAK3 enzyme with substrates and test compounds. The reactions were incubated at room temperature for 3 hours and terminated by adding 60 ul of 35 mM EDTA to each sample. Each reaction mixture was analyzed on the Caliper LabChip 3000 (Caliper, Hopkinton, Mass.) by electrophoretic separation of the fluorescent substrate and phosphorylated product. Inhibition data were calculated by comparison with no enzyme control reactions for 100% inhibition, and vehicle-only treated reactions for 0% inhibition. The final concentration of reagents in the assay was: ATP, 8 uM; fluoresceinated peptide, 1.5 uM.
- Kinase Assay The assay reactions were performed in U-bottom 384-well plates. The final assay volume was 30 ul prepared from 15 ul additions of enzyme and substrates (fluoresceinated peptide and ATP) and test compounds in assay buffer (20 mM HEPES pH 7.4, 10 mM MgCl2, 25 mM beta-glycerol phosphate, 0.015% Brij35 and 4 mM DTT). The reaction was initiated by the combination of GST-JAK1 enzyme with substrates and test compounds. The reactions were incubated at room temperature for 3 hours and terminated by adding 60 ul of 35 mM EDTA to each sample. Each reaction mixture was analyzed on the Caliper LabChip 3000 (Caliper, Hopkinton, Mass.) by electrophoretic separation of the fluorescent substrate and phosphorylated product. Inhibition data were calculated by comparison with no enzyme control reactions for 100% inhibition, and vehicle-only treated reactions for 0% inhibition. The final concentration of reagents in the assays was: ATP, 100 uM; fluoresceinated peptide, 1.5 uM.
- Kinase Assay The assay reactions were performed in U-bottom 384-well plates. The final assay volume was 30 ul prepared from 15 ul additions of enzyme and substrates (fluoresceinated peptide and ATP) and test compounds in assay buffer (20 mM HEPES pH 7.4, 10 mM MgCl2, 25 mM beta-glycerol phosphate, 0.015% Brij35 and 4 mM DTT). The reaction was initiated by the combination of GST-JAK1 enzyme with substrates and test compounds. The reactions were incubated at room temperature for 3 hours and terminated by adding 60 ul of 35 mM EDTA to each sample. Each reaction mixture was analyzed on the Caliper LabChip 3000 (Caliper, Hopkinton, MA) by electrophoretic separation of the fluorescent substrate and phosphorylated product. Inhibition data were calculated by comparison with no enzyme control reactions for 100% inhibition, and vehicle-only treated reactions for 0% inhibition. The final concentration of reagents in the assays was: ATP, 100 uM; fluoresceinated peptide.
- Kinase Glo Luminescence Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50 - 100 uM in test buffer (25 mM HEPES pH7.5; 25 mM MgCI2;5 mM MnCI2; 50 mM KCI; 0.2% BSA; 0.01 % CHAPS; 100 uM Na3V04; 0.5 mM DTT) and 10% glycerol at -80 C until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the protein kinase. Method:The test compounds were dissolved in 100 % DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM.
- Kinase Glo Luminescence Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 uM in test buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 0.2% BSA; 0.01% CHAPS; 100 uM Na3VO4; 0.5 mM DTT) and 10% glycerol at -80 C until use. The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the protein kinase. The test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM.
- MAO-A Inhibitory Assay A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100The count of the MAO-A enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-A enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- PKR KinaseGlo Assay Commercially available recombinant human GST-PKR (SignalChem, Canada; 1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Massachusetts, USA). The % inhibition for the compounds is calculated using ATP only (100% inhibition) and PKR+ATP (0% inhibition). IC50 values are determined by plotting % activity versus inhibitor concentration.
- RSV Polymerase Assay (RSVpol) Standard RSV polymerase assays were conducted in the presence of 3 μL extract of RSV-infected cells in a reaction buffer containing 50 mM tris-acetate pH 8, 120 mM K-acetate, 4.5 mM MgCl2, 5% glycerol, 2 mM EDTA, 50 μg/ml BSA, and 3 mM DTT. Varying concentration of NTPs were used to initiate RNA synthesis for 120 minutes at 30 degrees, and radioactive 33P GTP (15 μCi) was used as tracer. The reaction was stopped by adding 50 mM EDTA, and RNA samples were purified through G-50 size exclusion spin columns and phenol-chloroform extraction. The radio-labeled RNA products were resolved by electrophoresis on a 6% polyacrylamide TBE gel, and visualized and quantitated after being exposed on a phosphorImager screen. Polymerase inhibition experiments (IC50s) were conducted the same way in the presence of increasing concentration of NTP analogs.
- SPA Assay The assays were performed in U-bottom 384-well optiplates. The final assay volume was 15 ul prepared from 7.5 ul additions of microsomes (prepared as a high-speed pellet from homogenized HEK2 cells stably transfected with CYP17), substrates (3H-Pregnenolone and NADPH) and test compounds in assay buffer (50 mM Potassium phosphate pH 7.2, 10% glycerol). The reaction was initiated by the combination of the microsomes and substrates in wells containing compound. The reaction was incubated at room temperature for 45 minutes and terminated by adding 7.5 ul of 0.2N HCl to each well. Following an incubation period of 10 minutes, anti-DHEA-coated SPA beads were added to the terminated reaction. The plate was sealed and incubated overnight with shaking at 4 C. The beads were allowed to settle in the plate for 1 hour and the plate read on a TOPCOUNT (Perkin-Elmer) plate reader.Inhibition data were calculated by comparison to no enzyme control reactions for 100% inhibition.
- Scintillation Proximity Assay (SPA) The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 uL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 uM PIP2, 20 uM ATP, 0.2 uCi [gamma-33P]ATP, 4 nM PI3K delta. Reactions were incubated for 210 min and terminated by the addition of 40 uL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 uM ATP. The final concentration of SPA beads was 1.0 mg/mL.
- Thermal Shift Assay Binding analysis. Protein-ligand binding was identified with the thermal shift assay which is based on the ligand-induced stabilization of the protein tertiary structure. The thermal stability of the ligand-Akt1 complex was assessed by subjecting the complex to a set temperature gradient and by comparison of the meltion temperature of the Akt1-ligand complex with the melting temperature of the protein alone. Protein unfolding was monitored by the fluorescence readout of an environmentally sensitive fluorescent dye, 1-anilinonaphthalene-8-sulfonic acid (ANS). Protein-ligand mixture containing 15 uM compound, 200 ng/mL full length inactive Akt1, 200 uM ANS in the binding buffer (25 mM Tris-HCl (pH. 7.5), 100 mM NaCl, 10% Glycerol, and 5 mM DTT) was prepared in a PCR plate. The PCR plate was placed into a RT-PCR instrument and a temperature gradient was performed, increasing from 27 to 80 C., at 1 C./30 sec heat rate with a dwell time of 20 sec.
- Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) Assay PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2xKm ATP (100-300 uM), 10 uM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, 1% (v/v) DMSO at the following concentrations for each isoform: PI3K alpha, beta, delta, and gamma at 50 picomolar (pM) and PI3Kgamma at 2 nanomolar (nM). After an assay reaction time of 30 minutes at 25° C., reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 us delay and 500 us read window).
- Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) Binding Assay Probe 1:The assay was carried out in 18 uL low volume plates (Owens Corning) in reaction buffer (50 mM HEPES (NaOH), pH 7.5, 100 mM NaCl, 10 mM MgCl2, 1 mM DTT, 1% Glycerol) using 6.8 nM recombinant, human, C-terminally-His tagged NAMPT, 1 nM Tb-anti-His antibody (Invitrogen, Cat #PV5895), and 200 nM probe (Oregon Green 488-conjugated APO0866; A-1251667.0. Plates were covered, and reactions were carried out for 2-3 hours. Plates were read with Envision (Laser Lantha low volume protocol) after 2 to 3 hours. Excitation was carried out at 337 nm, and the ratio of emission of Oregon Green (520 nm) to terbium (492 nm) was determined and used to calculate IC50 values of test compounds.
- Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) Binding Assay Probe 2:The assay was carried out in 18 uL low volume plates (Owens Corning) in reaction buffer (50 mM HEPES (NaOH), pH 7.5, 100 mM NaCl, 10 mM MgCl2, 1 mM DTT, 1% Glycerol) using 6.8 nM recombinant, human, C-terminally-His tagged NAMPT, 1 nM Tb-anti-His antibody (Invitrogen, Cat #PV5895), and 200 nM probe (Oregon Green 488-conjugated APO0866; A-1287128.0. Plates were covered, and reactions were carried out for 2-3 hours. Plates were read with Envision (Laser Lantha low volume protocol) after 2 to 3 hours. Excitation was carried out at 337 nm, and the ratio of emission of Oregon Green (520 nm) to terbium (492 nm) was determined and used to calculate IC50 values of test compounds.
- Topoisomerase I Relaxation Assay Supercoiled pHOT1 DNA (0.5 μg) was incubated with four units of human topoisomerase I in relaxation buffer (10mM Tris-HCl (pH 7.8), 1mM EDTA, 0.15M NaCl, 0.1% BSA, 0.1 spermidine, 5% glycerol), in the presence of varying concentrations of the test compounds. Reactions were carried out at 37 °Cfor 1 h and then terminated by the addition of sodium dodecyl sulfate (SDS) to 0.25% and proteinase K to 50 μg/ml. The reaction mixture was subjected to electrophoresis through a 0.8% agarose gel containing 0.5 mg/ml ethidium bromide in TAE buffer (40mM Tris-borate and 1mM EDTA). The gels were stained with ethidium bromide and photographed under UV light. For the quantitative determination of topoisomerase concentration activity, photographic negatives were scanned and the area representing supercoiled DNA, migrating as a single band at the bottom of the gel was measured using UVI-KS4000i gel documentation and analysis system (SyngenBiotech, Sacramento, CA).
- Total SPA Assay The assays were performed in U-bottom 384-well optiplates. The final assay volume was 15 ul prepared from 7.5 ul additions of microsomes (prepared as a high-speed pellet from homogenized HEK2 cells stably transfected with CYP17), substrates (3H-Pregnenolone and NADPH) and test compounds in assay buffer (50 mM Potassium phosphate pH 7.2, 10% glycerol). The reaction was initiated by the combination of the microsomes and substrates in wells containing compound. The reaction was incubated at room temperature for 45 minutes and terminated by adding 7.5 ul of 0.2N HCl to each well. Following an incubation period of 10 minutes, anti-DHEA-coated SPA beads were added to the terminated reaction. The plate was sealed and incubated overnight with shaking at 4 C. The beads were allowed to settle in the plate for 1 hour and the plate read on a TOPCOUNT (Perkin-Elmer) plate reader.Inhibition data were calculated by comparison to no enzyme control reactions for 100% inhibition.
- BACE1 HTRF FRET Assay Reagents: Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide. A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence. Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined m value of 8 μM for the QSY7-APPswe-Eu substrate at BACE1.
- Biochemical Kinase Assay ABL1 WT protein (64-515aa) containing an N-terminal His tag was produced by co-expression with YopH in Sf9 insect cells. Cells were harvested by centrifugation and resuspended in 50 mM Tris, 500 mM NaCl, 5 mM β-ME, pH 8.2. Cells were lysed by sonication and clarified by centrifugation. ABL1 was purified by affinity chromatography using a HisTrap column with a wash step in 4% wash buffer (50 mM Tris, 500 mM NaCl, 500 mM imidazole, 5 mM β-ME, pH 8.2) and eluted in a linear gradient of the same buffer. Fractions containing ABL1 were pooled, concentrated and further purified using an ion exchange column washed with 50 mM Tris, pH 8.3 and eluted with a linear gradient of elution buffer (50 mM Tris, 1M NaCl, pH 8.3). Purified protein was stored at -80° C. in 50 mM Tris (pH 8.2), 300 mM NaCl, 1 mM DTT and 20% glycerol.
- Biological Assay CDK6/Cyclin D3: The purpose of the CDK6/Cyclin D3 assay is to evaluate the inhibition (% inhibition, Kiapp and Ki values) in the presence of small molecule inhibitors by using a fluorescence based microfluidic mobility shift assay. CDK6/Cyclin D3 catalyzes the production of ADP from ATP that accompanies the phosphoryl transfer to the substrate peptide 5-FAM-Dyrktide (5-FAM-RRRFRPASPLRGPPK) (SEQ ID NO:1). The mobility shift assay electrophoretically separates the fluorescently labeled peptides (substrate and phosphorylated product) following the kinase reaction. Both substrate and product are measured and the ratio of these values is used to generate % conversion of substrate to product by the LabChip EZ Reader. Typical reaction solutions contained 2% DMSO (±inhibitor), 2% glycerol, 10 mM MgCl2, 1 mM DTT, 3.5 mM ATP, 0.005% Tween 20 (TW-20), 3 μM 5-FAM-Dyrktide, 4 nM (active sites) activated CDK6/Cyclin D3 in 40 mM HEPES buffer at pH 7.5.
- Competitive Molecular Binding Assay The MR competitive binding assay is based on the binding and displacement of a TAMRA-labeled Dexamethasone probe with fluorescence polarization (FP) detection. The assay is performed in 384-well, low volume NBS black plates (Corning #3676) in assay buffer consisting of 10 mM TES, pH 7.4, 50 mM KCl, 20 mM Sodium molybdate, 1.5 mM EDTA, 0.04% CHAPS, 10% Glycerol and 1 mM DTT. Full Length human mineralocorticoid receptor (hMR) present in a baculovirus infected insect cell lysate is diluted 2 fold in assay buffer and 10 μL of this dilution is added to the assay plate. Blank wells receive 10 μL of the diluted MR lysate containing 3 μM Dexamethasone. 2 μL diluted test compound is transferred to the assay plate for a final starting top concentration of 10 μM in 1% DMSO. The reaction is started by adding 3 μL of 25 nM probe in assay buffer for a final assay concentration of 5 nM.
- DELFIA Assay This test uses active PTK2 enzyme (Invitrogen Code PV3832) and poly-Glu-Tyr (4:1, Sigma P-0275) as the kinase substrate. The kinase activity is detected by means of the phosphorylation of the substrate in a DELFIA assay. The phosphorylated substrate is detected with the Europium-labelled phosphotyrosine antibody PY20 (Perkin Elmer, No.: AD0038). In order to determine concentration-activity curves with PTK2-inhibitors the compounds are serially diluted in 10% DMSO/H2O and 10 L of each dilution are dispensed per well in a 96-well microtitre plate (clear U-shaped base plate, Greiner No. 650101) (the inhibitors are tested in duplicates) and mixed with 10 L/well of PTK2 kinase (0.01 ug/well). PTK2 kinase is diluted accordingly beforehand with kinase dilution buffer (20 mM TRIS/HCl pH 7.5, 0.1 mM EDTA, 0.1 mM EGTA, 0.286 mM sodium orthovanadate, 10% glycerol with the addition of freshly prepared BSA (fraction V 1 mg/mL) and DTT (1 mM)).
- Enzymatic Assay The TACE enzyme is an internal production (carried out according to the publication protein Eng Des Sel 2006, 19, 155-161) and is added so as to have a signal equivalent to 6 times the background noise in 2 h at 37° C. The reaction is carried out in 50 mM Tris buffered medium containing 4% glycerol, pH 7.4. The fluorescent substrate is MCA-Pro-Leu-Ala-Val-(Dpa)-Arg-Ser-Ser-Arg-NH2 (R&D systems, reference: ES003). The substrate is cleaved by the enzyme between the alanine and the valine, thus releasing a fluorescent peptide (excitation: 320 nm, emission: 420 nm). The substrate is used at 40 μM. The reaction is carried out in a final volume of 10 μl (4 μl inhibitor, 4 μl substrate, 2 μl enzyme) in a low volume 384-well plate (Corning reference: 3676). The plate is incubated at ambient temperature for 2 h, and then read by fluorescence on a Pherastar reader (BMG labtech).
- Enzyme Assay The TACE enzyme is an internal production (carried out according to the publication protein Eng Des Sel, 2006, 19, 155-161) and is added so as to have a signal equivalent to 6 times the background noise over 2 h at 37° C. The reaction takes place in a buffered medium: Tris 50 mM, 4% of glycerol, pH 7.4. The fluorescent substrate is MCA-Pro-Leu-Ala-Val-(Dpa)-Arg-Ser-Ser-Arg-NH2 (R&D system reference: ES003). The substrate is cleaved by the enzyme between alanine and valine thus releasing a fluorescent peptide (excitation: 320 nm, emission: 420 nm). The substrate is used at 40 μM. The reaction is carried out in a final volume of 10 μl (4 μl inhibitor, 4 μl substrate, 2 μl enzyme) in a plate of 384 low-volume wells (Corning reference: 3676). The plate is incubated for 2 h at ambient temperature, then read in fluorescence mode using a Pherastar (BMG labtech).
- Enzyme Assay This test uses active PTK2 enzyme (Invitrogen Code PV3832) and poly-Glu-Tyr (4:1, Sigma P-0275) as the kinase substrate. The kinase activity is detected by means of the phosphorylation of the substrate in a DELFIA assay. The phosphorylated substrate is detected with the europium-labelled phosphotyrosine antibody PY20 (Perkin Elmer, No.: AD0038).In order to determine concentration-activity curves with PTK2-inhibitors the compounds are serially diluted in 10% DMSO/H2O and 10 uL of each dilution are dispensed per well in a 96-well microtitre plate (clear U-shaped base plate, Greiner No. 650101) (the inhibitors are tested in duplicates) and mixed with 10 uL/well of PTK2 kinase (0.01 ug/well). PTK2 kinase is diluted accordingly beforehand with kinase dilution buffer (20 mM TRIS/HCl pH 7.5, 0.1 mM EDTA, 0.1 mM EGTA, 0.286 mM sodium orthovanadate, 10% glycerol with the addition of freshly prepared BSA (fraction V 1 mg/mL) and DTT (1 mM)).
- Enzyme Assay To check the B-Raf kinase inhibitory activity of the compounds of the present invention, the following experiments were conducted.(1) Serial Signaling: 20 ul of diluting solvent (20 mM MOPS, pH 7.2, 25 mM β-glycerol phosphate, 5 mM EGTA, 1 mM sodium orthovanadate, 1 mM dithiothreitol) and 10 ul of Mg/ATP mixed solution (500 uM ATP, 75 mM magnesium chloride) were added into a centrifuge tube, the derivative compound of Formula 1 was added or the compounds of the Examples were not added as a control group, and then 1 ng of activated B-Raf, 0.4 ng of inactivated MEK1, and 1 ug of inactivated MAPK2 were added. The solutions in the tube were collected on the bottom via centrifugation and were reacted at 30° C. for 30 minutes. After taking 4 ul of the mixed solution, the test proceeded to the next step.(2) Phosphorylation of Matrix Protein MBP by MAPK2: 10 ul of diluting solvent, 20 ug of MBP used as a matrix.
- Enzyme Inhibition Assay Human DGAT-1 activity was determined as follows: Assay buffer [20 mM HEPES (pH 7.4), 100 mM MgCl2, 0.04% BSA] containing 500 μM of enzyme substrate (didecanoyl glycerol) and 7.5 μM radiolabeled acyl-CoA substrate ([14C]decanoyl-CoA) was added to each well of a phospholipid FlashPlate (PerkinElmer Life Sciences). A small aliquot of lysate (5 μg/well) or mouse liver microsome (0.1 mg/well) was added to start the reaction, which was allowed to proceed in a 20° C. bath for 1 hour. and maintained overnight at room temperature. Next day, measurement was performed by Wallac 1450 Microbeta Trilux Liquid Scintillation Counter and Luminometer (PerkinElmer Life Science). In the control group, 0.1% DMSO was only added, and for the background value, 0.1% DMSO was only added without the cell fragment having the over-expressed human DGAT1 (5 μg/well) or the liver microsome of mice (0.1 mg/well), which was the same as the control group.
- HTRF FRET Assay Inhibitor IC50s at purified human autoBACE-2 were determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3x the desired final concentration in 1xBACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO were pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1xBACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30 C. The assay was initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 M for 4 M for autoBACE-2) prepared in 1xBACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30 C.
- HTRF FRET Assay Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies).
- HTRF FRET Assay Reagents: Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide (SEQ ID 1).A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide (SEQ ID 1)). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.
- HTRF assay Inhibitor IC50s at purified human autoBACE-2 were determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3x the desired final concentration in 1xBACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO were pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1xBACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30 C. The assay was initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1xBACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30 C.
- Hemoglobin Capture Assay The assay was performed at 37 °C in HEPES buffer (100 mM, with 10% glycerol, pH 7.4) in the presence of 10 uM L-arginine. Also included were 100 uM NADPH, 0.83 mM CaCl2, approximately 320 units/mL calmodulin, 10 uM tetrahydrobiopterin, andhuman oxyhemoglobin (3 uM). This assay was performed in 96-well plates using a Biotek Gen5 microplate reader. NO production was read by monitoring the absorbance at 401 nm (resulting from the conversion of oxyhemoglobin to methemoglobin). Kinetic readouts were recorded for 6 min. Each compound was assayed in at least duplicate, and seven to nine concentrations (from 50 nM to 200 uM) were used to construct dose-response curves. IC50 values were calculated by nonlinear regression using GraphPad Prism, and Ki values were obtained using the Cheng-Prusoff equation [Ki = IC50/(1 + [S]/Km)] with the following Km values: 1.3 uM for rat nNOS, 1.7 uM for the rat nNOS D597N mutant, and 1.9 uM for the rat nNOS.
- Homogeneous Time-Resolved FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence. Varying concentrations of inhibitors at 3x the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 u) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO.
- In Vitro Assay A PCR product covering residues 1058-1365 of c-Met (c-Met kinase domain) is generated from Human Liver QuickClone cDNA (Invitrogen) using forward primer 5'-ATTGACGGATCCATGCTAAATCCAGAGCTGGTCCAGGCA-3' (SEQ ID NO. 1) and reverse primer 5'-ACAACAGAATTCAATACGGAGCGACACATTTTACGTT-3' (SEQ ID NO. 2). The PCR product is cloned into a modified pFastBac 1 expression vector (harboring the gene for S. japonicum glutathione S-transferase immediately upstream of the multiple cloning site) using standard molecular biological techniques. The GST-c-Met kinase domain fusion (GST-Met) gene is transposed into full-length baculovirus DNA using the BacToBac system (Invitrogen). High5 cells are infected with the recombinant baculovirus for 72 h at 27 C. The infected cells are harvested by centrifugation and the pellet is stored at -80 C. The pellet is resuspended in buffer A (50 mM HEPES, pH 8.0, 0.25 M NaCl, 10 mM 2-mercaptoethanol, 10% (w/v) glycerol, 0.5% (v/v) protease.
- In Vitro Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 uM in test buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 0.2% BSA; 0.01% CHAPS; 100 uM Na3VO4; 0.5 mM DTT) and 10% glycerol at -80 C. until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the protein kinase. Method:The test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM. All further dilutions of the substances were carried out with 7.5% DMSO.
- In Vitro Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 uM in test buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 0.2% HSA; 0.01% CHAPS; 100 uM Na3VO4; 0.5 mM DTT) and 10% glycerol at -80 C. until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the protein kinase. Method:The test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM. All further dilutions of the substances were carried out with 7.5% DMSO.
- In Vitro Kinase Assay Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 uM in test buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 1% HSA; 0.01% CHAPS; 100 uM Na3VO4; 0.5 mM DTT) and 10% glycerol at -80 C. until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the protein kinase. Method:The test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM. All further dilutions of the substances were carried out with 7.5% DMSO.
- Inhibition Assay Plates assayed are 96-well polypropylene (Greiner) and 96-well 1.2 μm hydrophilic PVDF filter plates (Millipore). Concentrations reported here are final assay concentrations: 10-100 μM compounds in DMSO (Burdick and Jackson), 5-10 nM Btk enzyme (His-tagged, full-length), 30 μM peptide substrate (Biotin-Aca-AAAEEIYGEI-NH2), 100 μM ATP (Sigma), 8 mM imidazole (Sigma, pH 7.2), 8 mM glycerol-2-phosphate (Sigma), 200 μM EGTA (Roche Diagnostics), 1 mM MnCl2 (Sigma), 20 mM MgCl2 (Sigma), 0.1 mg/ml BSA (Sigma), 2 mM DTT (Sigma), 1 μCi 33P ATP (Amersham), 20% streptavidin sepharose beads (Amersham), 50 mM EDTA (Gibco), 2 M NaCl (Gibco), 2 M NaCl w/1% phosphoric acid (Gibco), microscint-20 (Perkin Elmer).
- Inhibiton Assay For studying inhibition of Plasmodium or human DHODH enzyme, two assays that are in routine use are described, for example, in Baldwin, et al. (2002) JBiol Chem., 277, 41827-41834, and Baldwin, et al. (2005) J. Biol. Chem., 280. 21847-21853.Briefly, this colorimetric assay monitors the reduction of 2,6-dichloroindophenol (DCIP) at 600 nm (e = 18.8 mM-1cm-1) for measuring DHOD inhibition. The assay was carried out using a solution containing 100 mM HEPES, pH 8.0, 150 mM NaCl, 10% glycerol, 0.1% Triton X-100, 20 micro molar CoQD (coenzyme QD), 200 micro molar L-dihydroorotate, and 120 micro molar DCIP. Reactions are initiated by addition of enzyme to a final concentration in the range of about 5 nM to about 50 nM while maintaining the temperature of a circulating water bath at 25° C. Alternatively, for potent compounds, activity was determined by directly measuring the production of orotic acid at 296 nm (ε = 4.3 mM-1 cm-1).
- Inhibitory Activity Assay The MAO-A inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100The count of the MAO-A enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-A enzyme non-addition conditions is indicated as blank.
- Inhibitory Activity Assay The MAO-A inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1-(test compound count-blank)/(control-blank))x100The count of the MAO-A enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-A enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- Kinase Assay CSF-1R: Inhibition of CSF-1R kinase activity by a test compound disclosed herein was estimated by AlphaScreen (PerkinElmer). Standard assay conditions were 1.25 ng of recombinant CSF-1R kinase (SignalChem) with 10 ng Biotin-conjugated Poly-(Glu 4:Tyr 1) (Cisbio) in the assay buffer (10 μM ATP, 10 mM MOPs, pH7.0, 0.21 mM EDTA, 0.5% glycerol, 1 mg/ml BSA, 0.01% 2-mercaptoethanol, 0.001% Brij35) in a final volume of 25 μL. Reactions were incubated at 30° C. for 45 min and stopped by adding 5 μL of 50 mM EDTA. Analysis of resulting product using an AlphaScreen kit, and counted with Enspire Alpha (PerkinElmer). The readout from control reaction (complete reaction mixture) was designated as 0% inhibition and the readout for the reaction without enzyme as 100% inhibition. The IC50 values of quinoxaline compounds of this invention against CSF-1R kinase were determined using the GraphPad Prism 5 software.
- MAO-B Inhibition Assay The MAO-B inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in 4% DMSO was added by 12.5 μL to 25 μL reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing 400 ng of MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 10 min. MAO substrate (Promega KK) (16 μM) was added by 12.5 μL to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate(%)=(1−(test compound count−blank)÷(control−blank))×100
- MAO-B Inhibitory Assay A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100The count of the MAO-B enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-B enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- MGAT LCMS Assay The MGAT enzyme reactions were performed in CORNING Falcon 96-well Polypropylene plates, in a total volume of 60 uL of 50 mM Potassium Phosphate buffer pH 7.4, containing a final concentration of 100 uM 2-oleoylglycerol, 15 uM oleoyl-Coenzyme A and 0.0013 ug/uL Human or Mouse MGAT-2 or 0.0026 ug/uL Rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 uL of ice cold methanol containing 1 ug/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters Symmetry C8, 50x2.1 mm column, was used for the chromatography of enzyme products.
- PKR KinaseGlo Assay Commercially available recombinant human GST-PKR (SignalChem, Canada; 1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Mass., USA). The % inhibition for the compounds is calculated using ATP only (100% inhibition) and PKR +ATP (0% inhibition). IC50 values are determined by plotting % activity versus inhibitor concentration. Curves are fitted using Activity base XLfit (IDBS, UK).
- Radioactive Kinase Assay The ATP-KM value of the complex is 61 uM. The kinase assays are run in the presence of 100 uM ATP using 10 uM of a substrate peptide. pAUB-IN847 was used to transform the E. coli strain BL21 (DE3) containing the pUBS520 helper plasmid. Both proteins and their mutants are expressed and purified under essentially identical conditions. Protein expression is induced with 0.3 mM IPTG at an OD6oo of 0.45-0.7. Expression is then continued for about 12-16 hours at 23-25 C with agitation. Bacterial cells are harvested by centrifugation at 4000 rpm x 15 min in a Beckman JLA 8.1 rotor, and the pellets resuspended in lysis buffer (50 mM Tris HCI pH 7.6, 300 mM NaCI, 1 mM DTT, 1 mM EDTA, 5 % glycerol, Roche Complete protease inhibitor tablets). 20-30 ml lysis buffer are used per liter of E. coli culture. Cells are lysed by sonication, and the lysates cleared by centrifugation at 12000 rpm for 45-60 min on a JA20 rotor.
- S-Adenosylhomocysteine Hydrolase (SAHase) Inhibition As a consequence of "D"-Isoneplanocin and "L"-Isoneplanocin, being isomers of Neplanocin A, which on one hand is a potent inhibitor of S-adenosylhomocysteine hydrolase (SAHase), a mechanism agreed upon as one source of its antiviral activity and on the other hand thought to contribute to cytotoxicity, the inhibitory efficiency on SAHase activity was assayed (source: rabbit erythrocytes). The inhibition of SAHase activity can be quantitated by the release of free homocysteine. SAHase from rabbit erythrocytes (Sigma) is dialyzed at 4° C. for 2 h in a buffer containing 20% glycerol and 50 mM potassium phosphate pH 7.4. The presence of adenosine deaminase insures that the reaction will proceed in the forward (hydrolysis) direction only. The enzyme preparation is incubated with or without the target compounds at different concentrations in 50 mM potassium phosphate buffer pH 7.4 for 5 minutes at 37° C. before SAH is added. The formation of homocysteine is detected using the Measure-iT thiol quantitation reagent according to the manufacturer's instructions (Life technologies, Carlsbad, Calif.). Plates are read on Spectra Max M2 (Molecular Devices).
- SPA Assay The Glucagon SPA assay is used to determine the ability of test compounds to block the binding of glucagon-cex to the glucagon receptor. Test compounds are re-suspended and serially diluted in 100% DMSO. 1 ul of test compound at the desired concentrations is spotted into the appropriate wells of 96 well low binding white clear bottom plate (Corning). 1 ul of DMSO is spotted into total binding wells. 1 ul of a known glucagon antagonist at a concentration of 20 uM is added to non specific binding wells. 0.3-0.75 ug of membrane from chem-1 cells stably transfected with the human glucagon receptor (Millipore), 125 pM of [125I]Glucagon-Cex (Perkin Elmer) and 175 ug of WGA PVT SPA beads (Perkin Elmer) are added to all wells of the assay plate. All assay ingredients with the exception of test compounds are re-suspended in the following buffer; 50 mM Hepes pH 7.4; 5 mM MgCl2; 1 mM CaCl; 5% glycerol and 0.2% BSA.
- Syk Kinase Inhibition Assay The in vitro inhibitory activity of the compound of the present invention against Syk kinase activity was assayed under the following conditions: the purified human Syk protein used in the test were purchased from Carna Biosciences, Inc. For the inhibitory activity assay on the compound, the compound of the present invention was first serially diluted with dimethyl sulfoxide (DMSO). Next, the purified human Syk protein FL-Peptide 22 (final concentration: 1 uM) (Caliper Life Sciences, Inc.), magnesium chloride (final concentration: 5 mM), ATP (final concentration: 30 uM), and each DMSO solution of the compound of the present invention (final concentration of DMSO: 5%) were added into a buffer solution for reaction (20 mM tris-HCl pH 7.5, 20 mM NaCl, 2.5 mM DTT, 0.02% Tween-20, 1% glycerol, 0.01 mM Pefabloc), and the mixture was then incubated at 25° C. for 30 minutes to perform kinase reaction. The kinase reaction was stopped by the addition thereto of EDTA.
- TACE Enzyme Assay The TACE enzyme is an internal production (carried out according to the publication Protein Eng Des Sel, 2006, 19, 155-161) and is added so as to have a signal equivalent to 6 times the background noise over 2 h at 37° C. The reaction takes place in a buffered medium: Tris 50 mM, 4% of glycerol, pH 7.4. The fluorescent substrate is MCA-Pro-Leu-Ala-Val-(Dpa)-Arg-Ser-Ser-Arg-NH2 (R&D system reference: ES003). The substrate is cleaved by the enzyme between alanine and valine thus releasing a fluorescent peptide (excitation: 320 nm, emission: 420 nm). The substrate is used at 40 uM. The reaction is carried out in a final volume of 10 ul (4 ul inhibitor, 4 ul substrate, 2 ul enzyme) in a plate of 384 low-volume wells (Corning reference: 3676). The plate is incubated for 2 h at ambient temperature, then read in fluorescence mode using a Pherastar (BMG labtech).
- BACE-1 Ki Assay (BACE-1 HTRF FRET Assay) The following reagents were used in this assay. Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE-1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide.A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE-1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE-1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE-1 enzyme. Inhibition of BACE-1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE-1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 milisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined μm value of 8 μM for the QSY7-APPswe-Eu substrate at BACE-1.
- Inhibitor Competition Assay Following transfection of HEK293 cells with pBJ5-HDAC1 wild type or mutant plasmids, [Weerasinghe et al., J. Med. Chem. 51:5542-5551; Wambua et al., J. Med. Chem. 57:642-650] as described above, cells were grown for 48 h and then subsequently treated with SAHA (10 uM in growth media containing DMEM, 10% FBS, 1% antibiotic/antimycotic, and <2% DMSO) for another 24 h before harvesting. Cells (20 x 1^06) were lysed in lysis buffer (500 uL; 50 mM Tris-Cl at pH 8.0, 150 mM NaCl, 10% glycerol, and 0.5% triton-X100) containing 1x protease inhibitor cocktail (GenDEPOT) at 4 °C for 30 min with rotation. The supernatant was collected using centrifugation at 13.2 x 10^3 rpm for 10 min at 4 °C. Prior to immunoprecipitation, anti-FLAG agarose beads (20 uL bead slurry) were washed with cold TBS (tris buffered saline; 20 mM Tris-Cl at pH 8.0, 150 mM NaCl) two times with spinning at 5000 rcf for 1 min at 4 °C. Wild type or mutant HDAC proteins were immunoprecipitated using the prewashed anti-FLAG agarose beads by incubating at 4 °C overnight with rotation. For inhibitor competition experiments, SHI-1:2 (10 uM in lysis buffer) or tubastatin (10 uM in lysis buffer) was included during immunoprecipitation. After immunoprecipitation, beads were washed three times with lysis buffer (1 mL), and bound proteins were eluted by incubating for 30 min at 4 °C using 3x FLAG peptide (APEXBIO; 50 uL; 0.25 mg mL in TBS). The eluted proteins were mixed with 4x SDS loading dye (25 uL; 100 mM Tris-Cl at pH 6.8, 4% SDS, 20% glycerol, 0.008% bromophenol blue, and 10% v/v β-mercaptoethanol), separated by 10% SDS-PAGE, and visualized with Sypro Ruby total protein stain (Molecular Probes) according to the manufacturer's instructions.
- Alpha Screen Assay Purified full-length inactive BTK (wild type and C481 mutant, N-terminal 6XHIS tagged BTK, Mwt=78.2 kDa) were activated using soluble inositol hexakisphosphate (IP6) and ATP as described (Q. Wang, E. M. Vogan, L. M. Nocka, C. E. Rosen, J. A. Zorn, S. C. Harrison J. Kuriyan, eLife 2015; 4:e06074), with minor modification. To 190 μl of 1 mM IP6 in activation buffer (25 mM Tris, pH 7.5, 150 mM NaCl, 5% glycerol) was added 10 μl of inactive BTK at 5-6 mg/ml and incubated for 10 min at room temperature followed by addition of 200 μl of 2 mM ATP in assay buffer (50 mM Tris, pH 8, 10 mM MgCl2, 1 mM EDTA, 0.1 mM NaF, 0.02 mg/ml BSA, 10% glycerol, 2 mM sodium orthovanadate, 0.25 mM DTT) for a further 10 min. The activated BTK was frozen in 50 μl aliquots (125-150 μg/ml).BTK activity was assayed using a PLCγ2-derived biotinylated peptide substrate (biotin-EELNNQLFLYDTHQNLR-OH) and AlphaScreen™ (Amplified Luminescent Proximity Homogeneous Assay) technology. The extent of peptide phosphorylation was determined by using acceptor beads conjugated to phosphotyrosine antibody that recognized the phosphorylated peptide and donor beads conjugated to streptavidin that binds to the biotin on the peptide. Excitation of the donor beads converted ambient oxygen to excited singlet oxygen which when in close proximity to acceptor beads, reacted with acceptor beads resulting in signal amplification.Test inhibitors and controls were prepared in 10% DMSO at 10-fold the desired final concentration and added to each well of a reaction plate (Corning 96-well half-area solid white nonbinding surface plate) in a volume of 2.5 μl. Full-length activated BTK (wildtype or mutant C481S) diluted to 0.179 nM in assay buffer (50 mM Tris, pH 8, 10 mM MgCl2, 1 mM EDTA, 0.1 mM NaF, 0.02 mg/ml BSA, 10% glycerol, 0.2 mM Na3VO4, 0.1 mM beta-glycerophosphate, 0.25 mM DTT) was added to each well in a volume of 17.5 μl and incubated with the inhibitors for 30 min. The kinase reaction was initiated by the addition of 5 μl of biotin-PLCγ2 peptide and ATP mixture diluted in assay buffer for a final concentration in the 25 μl reaction of 150 nM and 180 μM respectively and 0.125 nM enzyme. The plate was incubated for 120 min at room temperature and the reaction stopped by the addition of 10 μl stop/detection mixture containing 35 mM EDTA, 50 ug/ml AlphaScreen™ Streptavidin Donor beads (final concentration is 500 ng/well) and AlphaScreen™ Phospho-tyrosine (P-Tyr-100) Acceptor beads (final concentration is 500 ng/well) under green light conditions. The plate was incubated overnight at room temperature in the dark and the plates read on the BMG PolarStar Omega (excitation wavelength: 640 nm, emission wavelength: 570 nm, Gain=4000). Data were archived and analyzed with a 4-parameter fit to generate IC50 values using the CDD Vault from Collaborative Drug Discovery.
- AlphaScreen Assay The following example describes an assay that measured the ability of compounds to inhibit the binding of p53 to MDM2 using the AlphaScreen assay technology (PerkinElmer). The following protocol is an adaptation of the method described by H. R. Lawrence et al. (Bioorg. Med. Chem. Lett. 19 (2009) 3756-3759). Recombinant, truncated, human, N-terminal GST-MDM2 (aa 1-150) was obtained from GeneScript. Wild-type, full length human N-terminal 6-his p53 was purchased from SignalChem.Resulting in a final reaction volume of 24 μl PBS, 0.1% Tween-20, and 10% glycerol, 30 ng of MDM2 was added, followed by the addition of 10 of compound diluted in 100% DMSO that provided a final DMSO concentration of 4%. 30 ng of p53 was then added, mixed, and incubated at room temperature for 1 hour. Glutathione donor beads and Nickel acceptor beads (0.5 μg each; PerkinElmer) were added under subdued lighting conditions to a final reaction volume of 30 μl/well in a 96 well, ½ volume Proxima plate.
- Biological Assay Assay Method 1: T84 frozen pellets (contents of 1-4x15 cm culture dishes) were homogenized in 300 mL of FAAH assay buffer (125 mM Tris, 1 mM EDTA, 0.2% glycerol, 0.02% Triton X-100, 0.4 mM Hepes, pH 9). The assay mixture was prepared from 50 uL of the cell homogenate, 10 uL of the test compound, and 40 uL of anandamide [1-3H-ethanolamine] (3H-AEA; Perkin-Elmer, 10.3 Ci/mmol), which was added last, for a final tracer concentration of 200 nM. The reaction mixture was incubated at rt for 1 hour (h). During the incubation, 96-well Multiscreen filter plates (catalog number MAFCNOB50; Millipore, Bedford, Mass., USA) were loaded with 25 uL of activated charcoal (Multiscreen column loader, catalog number MACL09625, Millipore) and washed once with 100 uL of MeOH. Also during the incubation, 96-well DYNEX MicroLite plates (catalog number NL510410) were loaded with 100 uL of MicroScint40 (catalog number 6013641, Packard Bioscience, Meriden, Conn., USA).
- Caspase Catalytic Activity Assay Experiments were performed in a 384-well format (Greiner no. 781207) as per the conditions noted here. Caspase-1: 2.5 nM enzyme, 6.5 mM WEHD substrate, ECB; Caspase-3: 200 nM enzyme, 3.3 mM DEVD substrate, SCB; Caspase-4: 1 nM enzyme, 10 mM LEHD substrate, HCB; Caspase-5: 20 nM enzyme, 10 mM LEHD substrate, HCB; Caspase-9: 200 nM enzyme, 6.5 mM LEHD substrate, HCB. ECB (Enzo Caspase Buffer): 50 mM HEPES (pH 7.4), 100 mM NaCl, 0.5% Tween 20, 10 mM DTT, and 10% glycerol; SCB (Standard Caspase Buffer): 20 mM PIPES (pH 7.5), 100 mM NaCl, 1 mM EDTA, 10 mM DTT, and 10% sucrose; HCB (High-Citrate Buffer): 50 mM Tris-HCl (pH 7.5), 1 M sodium citrate, 10 mM DTT, and 10% sucrose. Activity was measured as the change in luminescent signal for at least 30 min.
- Enzymatic Assay The products are solubilized in DMSO at a concentration of 10 mM. A serial 3-fold dilution over 10 points is carried out so as to have a concentration range of from 10 uM to 0.5 nM final concentration. The TACE enzyme is an internal production (carried out according to the publication protein Eng Des Sel 2006, 19,155-161) and is added so as to have a signal equivalent to 6 times the background noise in 2 h at 37C. The reaction is carried out in 50 mM Tris buffered medium containing 4% glycerol, pH 7.4. The fluorescent substrate is MCA-Pro-Leu-Ala-Val-(Dpa)-Arg-Ser-Ser-Arg-NH2 (R&D systems, reference: ES003). The substrate is cleaved by the enzyme between the alanine and the valine, thus releasing a fluorescent peptide (excitation: 320 nm, emission: 420 nm). The substrate is used at 40 uM. The reaction is carried out in a final volume of 10 ul (4 ul inhibitor, 4 ul substrate, 2 ul enzyme) in a low volume 384-well plate (Corning reference: 3676).
- Enzyme Activity Assay The potency of compounds of formula I against the stearoyl-CoA desaturase was determined by measuring the conversion of radiolabeled stearoyl-CoA to oleoyl-CoA using rat liver microsome or human SCD1 following previously published procedures with some modifications (Joshi, et al., J. Lipid Res., 18: 32-36 (1977); Talamo, et al., Anal. Biochem, 29: 300-304 (1969)). Liver microsome was prepared from male Wistar or Sprague Dawley rats on a high carbohydrate diet for 3 days (LabDiet #5803, Purina). The livers were homogenized (1:10 w/v) in a buffer containing 250 mM sucrose, 1 mM EDTA, 5 mM DTT and 50 mM Tris-HCl (pH 7.5). After a 100,000xg centrifugation for 60 min, the liver microsome pellet was suspended in a buffer containing 100 mM sodium phosphate, 20% glycerol, 2 mM DTT, and stored at -78° C. Human SCD1 desaturase system was reconstituted using human SCD1 from a baculovirus/Sf9 expression system, cytochrome B5 and cytochrome B5 reductase.
- FAAH Assay T84 frozen cell pellets or transfected SK-N-MC cells (contents of 1x15 cm culture dishes) were homogenized in 50 mL of FAAH assay buffer (125 mM Tris, 1 mM EDTA, 0.2% Glycerol, 0.02% Triton X-100, 0.4 mM Hepes, pH 9). The assay mixture consisted of 50 uL of the cell homogenate, 10 uL of the test compound, and 40 pt of anandamide [1-3H-ethanolamine] (3H-AEA, Perkin-Elmer, 10.3 Ci/mmol), which was added last, for a final tracer concentration of 80 nM. The reaction mixture was incubated at rt for 1 h. During the incubation, 96-well Multiscreen filter plates (catalog number MAFCNOB50; Millipore, Bedford, Mass., USA) were loaded with 25 uL of activated charcoal (Multiscreen column loader, catalog number MACL09625, Millipore) and washed once with 100 uL of MeOH. Also during the incubation, 96-well DYNEX MicroLite plates (catalog number NL510410) were loaded with 100 uL of MicroScint40 (catalog number 6013641, Packard Bioscience, Meriden, Conn., USA).
- FAAH Assay T84 frozen cell pellets or transfected SK-N-MC cells (contents of 1x15 cm culture dishes) were homogenized in 50 mL of FAAH assay buffer (125 mM Tris, 1 mM EDTA, 0.2% Glycerol, 0.02% Triton X-100, 0.4 mM Hepes, pH 9). The assay mixture consisted of 50 uL of the cell homogenate, 10 uL of the test compound, and 40 uL of anandamide [1-3H-ethanolamine] (3H-AEA, Perkin-Elmer, 10.3 Ci/mmol), which was added last, for a final tracer concentration of 80 nM. The reaction mixture was incubated at rt for 1 h. During the incubation, 96-well Multiscreen filter plates (catalog number MAFCNOB50; Millipore, Bedford, Mass., USA) were loaded with 25 uL of activated charcoal (Multiscreen column loader, catalog number MACL09625, Millipore) and washed once with 100 uL of MeOH. Also during the incubation, 96-well DYNEX MicroLite plates (catalog number NL510410) were loaded with 100 uL of MicroScint40 (catalog number 6013641, Packard Bioscience, Meriden, Conn., USA).
- FRET Assay The protocol is a modified FRET-based assay (v_03) developed to evaluate compound potency, rank-order and resistance profiles against wild type and C159S, A156S, A156T, D168A, D168V, R155K mutants of the HCV NS3/4A 1b protease enzyme as follows: 10× stocks of NS3/4A protease enzyme from Bioenza (Mountain View, Calif.) and 1.13× 5-FAM/QXL™520 FRET peptide substrate from Anaspec (San Jose, Calif.) were prepared in 50 mM Tris-HCl, pH 7.5, 5 mM DTT, 2% CHAPS and 20% glycerol. 5 μL of each enzyme were added to Corning (#3575) 384-well, black, microtiter plates (Corning, N.Y.) after spotting a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Protease reactions were immediately started after enzyme addition with the addition of 45 μL of the FRET substrate and monitored for 60-90 minutes at λex485/λem520 in a Synergy4 plate reader from BioTek (Winooski, Vt.).
- Fluorescence Polarisation Assay In a black, 384-well polystyrene assay plate, 30 microliters/well of 5 nM Escherichia coli DNA gyrase A/B tetramer and 130 micrograms/mL of topological^ relaxed plasmid containing the triplex-forming sequence TTCTTCTTCTTCTTCTTCTTCTTCTTC (SEQ ID NO: 1) in an assay buffer consisting of 35 mM Tris-HCI (pH 7.5), 24 mM KCI, 4 mM MgCI2, 2 mM dithiothreitol, 1.8 mM spermidine, 5% (v/v) glycerol, 200 nM bovine serum albumin, 0.8%dimethylsulfoxide, and 0.3 mM ATP were incubated at ambient temperature for (typically 30 minutes) in the absence or presence of 5 -10 different concentrations of test compound. The supercoiling reactions were quenched by the addition of 10 microliters/well of 40 nM oligodeoxynucleotide probe in 3X triplex-forming buffer consisting of 150 mM NaCI, and 150 mM sodium acetate at pH 3.5. The oligodeoxynucleotide probe was 5'-BODIPY-FL-labeled TTCTTCTTC (SEQ ID NO:2). After 60 minutes, the fluorescence anisotropy of the BODIPY- FL was measured in a Tecan Ultra plate.
- Fluorescence Polarisation Assay In a black, 384-well polystyrene assay plate, 30 microliters/well of 5 nM Escherichia coli DNA gyrase A/B tetramer and 130 micrograms/ml of topologically relaxed plasmid containing the triplex-forming sequence TTCTTCTTCTTCTTCTTCTTCTTCTTC in an assay buffer consisting of 35 mM Tris-HCl (pH 7.5), 24 mM KCl, 4 mM MgCl2, 2 mM dithiothreitol, 1.8 mM spermidine, 5% (v/v) glycerol, 200 nM bovine serum albumin, 0.8% dimethylsulfoxide, and 0.3 mM ATP may be incubated at ambient temperature for (typically 30 minutes) in the absence or presence of 5-10 different concentrations of test compound. The supercoiling reactions may be quenched by the addition of 10 microliters/well of 40 nM oligodeoxynucleotide probe in 3x triplex-forming buffer consisting of 150 mM NaCl, and 150 mM sodium acetate at pH 3.5. The oligodeoxynucleotide probe may be 5x-BODIPY-FL-labeled TTCTTCTTC. After 60 minutes, the fluorescence anisotropy of the BODIPY-FL may be measured in a Tecan Ultra plate reader, using 485 nM.
- Glucan Synthase Assay The glucan synthase assay follows the incorporation of tritiated UDP-glucose into acid insoluble β-glucan as catalysed by the glucan synthase activity present in membrane preparations from Candida albicans and Aspergillus fumigatus. UDP-[3H]-glucose (ca 0.01 μCi) is added to 100 μl assay buffer (50 mM Tris-Cl, pH8.0, 8% glycerol, 1 mM EDTA, 1.5 mM KF, 1 mM DTT, 20 μM GTPγS, 600 μM UDP-glucose) and the reaction initiated by the addition of 2.5 μl of enzyme preparation. After incubation at 30°C. for 120 minutes, 10 μl of 30 mg/ml BSA is added with mixing and the reaction is terminated with 110 μl ice-cold 20% TCA. The precipitate is collected on a GF/B filter plate and washed three times with 200 μl water. Once dry, 200 μl of Microscint20 is added to each well and the plate is read on a Top-count scintillation counter.
- GyraseB Assay Initially, equimolar quantities of about 0.5µM each of E. coli gyraseA and S. aureus gyraseB were incubated for a period of 45 min with salmon sperm DNA (Sigma) in 50mM Tris (pH 7.5), 75mM ammonium acetate buffer for the reconstitution of the hybrid topoisomerases at 4 OC. Later the assay was performed in a 96-well microtiter plate as mentioned earlier (7). The assay buffer includes 50 mM Tris (pH 7.5), 75 mM ammonium acetate, 5% w/v glycerol, 0.5mM ΕDTA, 6 mM magnesiumchloride, 0.001% Triton X-100, 1 mMdithiothreitol, DNA of 2 μg/mL (~3 μM base pairs), 250µM ATP, 2.2nM of E. coligyrase A and S. aureusgyraseB. Reactions were performed with various drug concentration ranges for the calculation of IC50, with a negative moxifloxacin and positive novobiocin control as standards. The reaction was allowed to proceed for 60 min and was quenched by addition of 20uL of malachite green reagent (POMG-25H, Bioassay systems, USA) subsequently absorbance was read at 650nm after 20 mi
- HTRF FRET Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light Inhibitor compounds, prepared at 3x the desired final concentration in 1x BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1x BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1x BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C.
- In Vitro Assay ADAMTS-4:The basis for the assay is the cleavage of the substrate TBIS-1 (5-FAM-TEGEARGSVILLK (5TAMRA)K-NH2) (SEQ ID No 2) by human ADAMTS4For the dose response (10 point), 4 μL of a dilution series of compound (2 mM highest concentration, 1/5 dilution in DMSO further diluted 1 in 10 in water corresponding to a final highest concentration of 20 μM), is transferred to 384 well Fluotrac 200 plate (Greiner, cat #781076) and incubated at room temperature for 30 min with a 26 μL buffer solution (50 mM Hepes pH7.5, 100 mM NaCl, 5 mM CaCl2, 0.1% CHAPS, 5% glycerol) containing hADAMTS4 (0.325 ng/L) (it will be appreciated by the skilled person that the potency read out is independent of the enzyme concentration).The reaction is initiated by adding to the assay plate TBIS-1 (10 μL, 4.5 μM, Anaspec) in the same buffer.Finally, the fluorescence is read on the Envision (Perkin Elmer) after an incubation of 60 min at room temperature (Excitation 485 nm, emission 535).
- In Vitro Assay ADAMTS-5:Protocol 1: The basis for the assay is the cleavage of the substrate TBIS-1 (5 FAM-TEGEARGSVILLK (5TAMRA)K-NH2) (SEQ ID No 2) by human ADAMTS-5.For the dose response (10 point), 4 μL of a dilution series of compound (2 mM highest concentration, 1/5 dilution in DMSO further diluted 1 in 10 in water, corresponding to a final highest concentration of 20 μM), is transferred to 384 well Fluotrac 200 plate (Greiner, cat #781076) and incubated at room temperature for 30 min with a 26 μL buffer solution (50 mM Hepes pH7.5, 100 mM NaCl, 5 mM CaCl2, 0.1% CHAPS, 5% glycerol) containing hADAMTS-5 (0.5 ng/L) (it will be appreciated by the skilled person that the potency read out is independent of the enzyme concentration).The reaction is initiated by adding to the assay plate TBIS-1 (10 μL, 4.5 μM, Anaspec) in the same buffer.Finally, the fluorescence is read on the Envision (Perkin Elmer) after an incubation of 60 min at Room Temperature (Excitation 485 nm, emission 530).
- In Vitro Assay TABLE V: The basis for the assay is the cleavage of the substrate TBIS-1 (5-FAM-TEGEARGSVILLK (5TAMRA)K-NH2) (SEQ ID NO: 2) by human ADAMTS4.For the dose response (10 point), 4 μL of a dilution series of compound (2 mM highest concentration, ⅕ dilution in DMSO further diluted 1 in 10 in water corresponding to a final highest concentration of 20 μM), is transferred to 384 well Fluotrac 200 plate (Greiner, cat #781076) and incubated at room temperature for 30 min with a 26 μL buffer solution (50 mM Hepes pH7.5, 100 mM NaCl, 5 mM CaCl2, 0.1% CHAPS, 5% glycerol) containing hADAMTS4 (0.325 ng/μL) (it will be appreciated by the skilled person that the potency read out is independent of the enzyme concentration).The reaction is initiated by adding to the assay plate TBIS-1 (10 μL, 4.5 μM, Anaspec) in the same buffer.Finally, the fluorescence is read on the Envision (Perkin Elmer) after an incubation of 60 min at room temperature (Excitation 485 nm, emission 535).
- In Vitro Enzyme Activity Assay The full-length coding sequences of human TPH1 and TPH2 were PCR amplified, ligated into a MBP fusion vector (pMalc2x, New England Biolabs, MA, USA) and transformed into SCS1 (Stratagene, CA, USA) to amplify plasmid DNA. For the overexpression of TPH proteins, the constructs were transformed into Rosetta (DE3) (Novagen®/EMD Millipore, MA, USA) and cultivated in terrific broth (TB) medium (AppliChem, Darmstadt, Germany) at 37° C. When the bacterial cultures reached an OD600≈2, expression was induced with 0.5 mM IPTG (AppliChem, Darmstadt, Germany) over night at 17° C. The purification of soluble proteins started with sonication-mediated cell disruption in lysis buffer (1×PBS pH 7.4, 0.5 M NaCl, 5 Glycerol+CHAPS, DTT, PMSF, benzonase), followed by affinity purification (MBPTrap, GE Healthcare, UK) and gel filtration (26/60 Superdex 200 prep grade, GE Healthcare, UK), according to the manufacturer's protocol. The quality of protein expression and solubility was controlled by SDS-PAGE and Coomassie blue staining.
- Inhibition Assay Mouse VCP cDNA was added with a DNA sequence corresponding to histidine tag at the amino-terminal, subcloned into a baculovirus vector pVL1392 (BD Bioscience), and expressed in Sf-9 insect cells. The protein was purified with a nickel column (GE Healthcare). The concentration of the protein was adjusted to 0.25-0.5 ug/ml and the protein was stored in a solution containing 50 mM TrisCl pH 8.0, 5 mM EDTA, 10% glycerol, and 15 mM DTT. The ATPase activity was determined as follows. 500 ng of the purified VCP was mixed with 100 uM [gamma-32P]ATP (18.5 GBq/mmol) and the test substance in 20 uL of ATPase buffer (20 mM HEPES (pH7.4), 50 mM KCl, 5 mM MgCl2, 15 mM DTT), and incubated at 37° C. for 10 minutes.The enzyme reaction was stopped with addition of 200 uL of an ice-cold solution containing 7% TCA and 1 mM K2HPO4. 50ul of a solution containing 3.75% ammonium molybdate and 0.02M tungstate silicic/3 NH2SO4 was added, followed by 300 uL of n-butylacetic acid.
- Inhibition Assay PI3K enzymatic activity was assayed by measuring the amount of product phosphatidylinositol 3,4,5-phosphate (PIP3) formed from substrate 4,5 phosphatidylinositol 4,5-phosphate (PIP2) using a fluorescence polarization displacement assay. The decrease in fluorescence polarization of a fluorescent PIP.sub.3 probe is measured as it is displaced from a PIP.sub.3-binding protein GRP-1 detector by PI3K-catalyzed product. Assays were conducted in 384-well black Proxiplates in the presence of 10 mM Tris (pH 7.5), 50 mM NaCl, 4 mM MgCl.sub.2, 5% glycerol, 25 .mu.M ATP, 10 .mu.M PIP.sub.2 (Echelon Biosciences), 0.05% 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, 1 mM dithiothreitol, and 2% DMSO. The kinase reactions were initiated by the addition of 40 ng/mL p110.alpha./p85.alpha., 300 ng/mL p110.beta./p85.alpha., 40 ng/mL p110.gamma., or 40 ng/mL p110.delta./p85.alpha. (Upstate Group, Millipore; Dundee, UK), and 10 .mu.M PIP.sub.2 (Echelon Biosciences) to the wells.
- Inhibition Assay The assay is a capture of radioactive 33P phosphorylated product through filtration. The interactions of Btk, biotinylated SH2 peptide substrate (Src homology), and ATP lead to phosphorylation of the peptide substrate. Biotinylated product is bound streptavidin sepharose beads. All bound, radiolabeled products are detected by scintillation counter.Plates assayed are 96-well polypropylene (Greiner) and 96-well 1.2 um hydrophilic PVDF filter plates (Millipore). Concentrations reported here are final assay concentrations: 10-100 uM compounds in DMSO (Burdick and Jackson), 5-10 nM Btk enzyme (His-tagged, full-length), 30 uM peptide substrate (Biotin-Aca-AAAEEIYGEI-NH2), 100 uM ATP (Sigma), 8 mM imidazole (Sigma, pH 7.2), 8 mM glycerol-2-phosphate (Sigma), 200 uM EGTA (Roche Diagnostics), 1 mM MnCl2 (Sigma), 20 mM MgCl2 (Sigma), 0.1 mg/ml BSA (Sigma), 2 mM DTT (Sigma), 1 uCi 33P ATP (Amersham), 20% streptavidin sepharose beads (Amersham), 50 mM EDTA (Gibco).
- Inhibitory Activity Assay The MAO-B inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100The count of the MAO-B enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-B enzyme non-addition conditions is indicated as blank.
- Kinase Assay In a dilution series 10 uL/well of test substance solution are placed in a multiwell plate. The dilution series is selected so that generally a range of concentrations of 2 uM to 0.119 nM or 0.017 nM is covered. If necessary the initial concentration of 2 uM is changed to 50 uM, 10 uM, 0.4 uM or 0.2857 uM and further dilution is carried out accordingly. The final concentration of DMSO is 5%. 10 uL/well of the B-Raf (V600E)-kinase solution are pipetted in (containing 0.5 ng B-Raf (V600E)-kinase, e.g. from Upstate) in 20 mM Tris-HCl pH 7.5, 0.1 mM EDTA, 0.1 mM EGTA, 0.286 mM sodium orthovanadate, 10% glycerol, 1 mg/mL bovine serum albumin, 1 mM dithiothreitol) and the mixture is incubated for 1 h at RT with shaking. The kinase reaction is started by the addition of 20 uL/well ATP solution [final concentration: 250 uM ATP, 30 mM Tris-HCl pH 7.5, 0.02% Brij, 0.2 mM sodium orthovanadate, 10 mM magnesium acetate, 0.1 mM EGTA.
- Kinase Assay Inhibition of C-kit kinase activity by compounds disclosed herein was quantified by measuring the amount of [33P] incorporated into the substrate in the presence of a test compound. Briefly, a reaction mixture of 25 uL final volume containing 5 ng of C-kit kinase (obtained by purifying recombinant N-terminal 6xHis-tagged C-kit kinase domain construct expressed from baculovirus), 5 ug of the substrate [Poly (Glu-Tyr, 4:10, Sigma], kinase reaction buffer (8 mM MOPS/NaOH pH7.0, 0.2 mM EDTA, 10 mM MnCl2, 0.5% glycerol, 0.001% Brij-35, 0.01%, 2-mercaptoethanol, 0.1 mg/ml BSA, 100 uM ATP, 0.1 uCi per well [33P]-gamma-ATP (2,500-3,000 Ci/mmol)), and a test compound (diluted from 9 uM to the desired final concentration by 4% DMSO) or DMSO (as the control) was incubated at 30C. for 30 minutes. The reaction was stopped by adding 5 uL of 3% phosphoric acid solution. The resultant solution (30 uL) was later harvested by a UniFilter Plate GF/B (PerkinElmer).
- Kinase Assay Inhibition of PDGFR-beta kinase activity by compounds disclosed herein was quantified by measuring the amount of [33P] incorporated into the substrate in the presence of a test compound. Briefly, a reaction mixture of 25 uL final volume containing 55 ng of PDGFR-beta kinase (obtained by purifying recombinant N-terminal 6xHis-tagged PDGFR-beta kinase domain construct expressed by baculovirus), 2.5 ug of the substrate [Poly (Glu-Tyr, 4:1), Sigma], kinase reaction buffer (20 mM MOPS pH 7.0, 1 mM EDTA, 5% glycerol, 0.01% Brij-35, 0.1% beta-mercaptoethanol, 1 mg/mL BSA, 2 mM MnCl2, 30 nM ATP, 0.1 uCi per well [33P]-gamma-ATP (2,500-3,000 Ci/mmol)), and a test compound (diluted from 9 uM to the desired final concentration by 4% DMSO) or DMSO (as the control) was incubated at 30C. for 30 minutes. The reaction was stopped by adding 5 uL of 3% phosphoric acid solution. The resultant solution (30 uL) was later harvested by a UniFilter Plate GF/B (PerkinElmer).
- Kinase Assay The assay reactions were performed in U-bottom 384-well plates. The final assay volume was 30 μl prepared from 15 μl additions of enzyme and substrates (fluoresceinated peptide and ATP) and test compounds in assay buffer (100 mM HEPES pH 7.4, 10 mM MgCl2, 25 mM beta-glycerol phosphate 0.015% Brij35 and 4 mM DTT). The reaction was initiated by the combination of GST-JAK3 enzyme with substrates and test compounds. The reactions were incubated at room temperature for 3 hours and terminated by adding 60 μl of 35 mM EDTA to each sample. Each reaction mixture was analyzed on the Caliper LABCHIP® 3000 (Caliper, Hopkinton, Mass.) by electrophoretic separation of the fluorescent substrate and phosphorylated product Inhibition data were calculated by comparison with no enzyme control reactions for 100% inhibition, and vehicle-only treated reactions for 0% inhibition. The final concentration of reagents in the assay was: ATP, 8 μM; fluoresceinated peptide, 1.5 μM; GST-JAK3, 4.5 nM; and DMSO, 1.6%.
- Kinase Assay The assay reactions were performed in U-bottom 384-well plates. The final assay volume was 30 μl prepared from 15 μl additions of enzyme and substrates (fluoresceinated peptide and ATP) and test compounds in assay buffer (20 mM HEPES pH 7.4, 10 mM MgCl2, 25 mM beta-glycerol phosphate, 0.015% Brij35 and 4 mM DTT). The reaction was initiated by the combination of GST-JAK1 enzyme with substrates and test compounds. The reactions were incubated at room temperature for 3 hours and terminated by adding 60 μl of 35 mM EDTA to each sample. Each reaction mixture was analyzed on the Caliper LABCHIP® 3000 (Caliper, Hopkinton, Mass.) by electrophoretic separation of the fluorescent substrate and phosphorylated product Inhibition data were calculated by comparison with no enzyme control reactions for 100% inhibition, and vehicle-only treated reactions for 0% inhibition. The final concentration of reagents in the assays was: ATP, 100 μM; fluoresceinated peptide, 1.5 μM; GST-JAK1, 12.5 nM; and DMSO, 1.6%.
- Luminex Assay The cellular assay for the determination of the PDK1 kinase activity is carried out as a Luminex assay in the 96-well format. PC3 cells are sown at 20,000 cells per well in 100 ul of medium (45% of RPMI1460/45% of Ham's F12/10% of FCS) and incubated on the following day for 30 min with a serial dilution of the test substance (7 concentrations) under serum-free conditions. The cells are subsequently lysed using 90 ul of lysis buffer (20 mM tris/HCl pH 8.0, 150 mM NaCl, 1% of NP40, 10% of glycerol, 1% of phosphatase inhibitor I, 1% of phosphatase inhibitor II, 0.1% of protease inhibitor cocktail III, 0.01% of benzonase) per well, and the lysates are separated off from insoluble cell constituents by means of centrifugation through a 96-well filter plate (0.65 um). The lysates are incubated overnight at 4° C. with shaking with Luminex beads to which an anti-total PKB antibody is coupled. The detection is carried out on the following day by addition of a phospho-T308-PKB antibody and a species-specific peroxidase-labelled secondary antibody.
- MAO-A Inhibitory Activity The MAO-A inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100The count of the MAO-A enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-A enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- MAO-A Inhibitory Assay The MAO-A inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol) containing MAO-A enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-A inhibitory rate (%) of the test compound was calculated by the following formula. inhibitory rate (%)=(1−(test compound count−blank) (control−blank))×100The count of the MAO-A enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-A enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- Omnia Assay Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25°ree; C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.).
- Omnia Assay Protocol Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 27° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 30-90 seconds for 60 minutes at λex360/λcm485 in a Synergy4 plate reader from BioTek (Winooski, Vt.).
- PKR KinaseGlo Assay Commercially available recombinant human GST-PKR (SignalChem, Canada; 1.5 uM-2 uM stock) is diluted to 500 nM in assay buffer (20 mM Tris-HCl, pH 7.2, 10 mM KCl, 10 mM MgCl2, 10% glycerol). Preactivated PKR is dispensed to 384/96-well black plates at 3.125/12.5 uls/well using the liquid handler Janus. Appropriate dilutions of inhibitors are added to 384/96-well plate followed by 6.6 uM ATP (final) and incubated for 10 minutes at room temperature. The remaining ATP/well is determined by adding 6.25/25 uls/well Kinase-Glo assay mix (Promega) and luminescence is measured on EnVision luminescence plate reader (integration time, 0.2 sec; Perkin-Elmer, Massachusetts, USA). The % inhibition for the compounds is calculated using ATP only (100% inhibition) and PKR+ATP (0% inhibition). IC50 values are determined by plotting % activity versus inhibitor concentration. Curves are fitted using Activity base XLfit (IDBS, UK) using the formula— 4 Parameter Logistic Model.
- Radioligand Binding Assay Compounds of the invention were assessed in a competition binding assay where different concentrations of compounds were incubated with the LXR ligand binding domain (LBD) in the presence of radiolabeled LXR ligand [3H]TO901317. The amount of the LXR-LBD that complexed with [3H]T0901317 was measured by scintillation proximity assay (SPA) employing non-specific binding of LXR-LBD to poly-lysine coated Yttrium silicate beads. Partially purified LXR alpha or beta LBD protein (15-45 nM) was incubated at rt for 30 min with 15 nM [3H]T0901317 (25-40 Ci/mmol) and different concentrations of test compounds in 80 uL of phosphate buffered saline (PBS) buffer containing 2.5% DMSO, 1% glycerol, 2 mM EDTA, 2 mM CHAPS and 5 mM DTT in 96-well plates. Poly-lysine SPA beads (50 ug) were added to each well and the total volume was adjusted to 120 uL. The plates were shaken on an orbital shaker for 20 min and then allowed to settle for 10 more minutes at room temperature.
- Radioligand Binding Assay Compounds of the invention were assessed in a competition binding assay where different concentrations of compounds were incubated with the LXR ligand binding domain (LBD) in the presence of radiolabeled LXR ligand [3H]TO901317. The amount of the LXR-LBD that complexed with [3H]T0901317 was measured by scintillation proximity assay (SPA) employing non-specific binding of LXR-LBD to poly-lysine coated Yttrium silicate beads. Partially purified LXR alpha or beta LBD protein (15-45 nM) was incubated at rt for 30 min with 15 nM [3H]TO901317 (25-40 Ci/mmol) and different concentrations of test compounds in 80 uL of phosphate buffered saline (PBS) buffer containing 2.5% DMSO, 1% glycerol, 2 mM EDTA, 2 mM CHAPS and 5 mM DTT in 96-well plates. Poly-lysine SPA beads (50 ug) were added to each well and the total volume was adjusted to 120 uL. The plates were shaken on an orbital shaker for 20 min and then allowed to settle for 10 more minutes at rt.
- Radioligand Binding Assay In the GR radioligand binding assay, test compounds were serially diluted in semi-log steps (10 concentrations) with a final concentration of 10 uM. Test compounds (1 uL) and controls (1 uL) in 100% DMSO were added to 96 Greiner V-bottom polypropylene plates. 0% control was 6.7% DMSO (final concentration in assay) and 100% control was 6.7 uM Dexamethasone.The full length GR was diluted to a final concentration of 3.3% (0.495 mg/ml) in assay buffer (20 mM Tris-HCl, 1 mM EDTA, 10% (w/v) Glycerol, 20 mM Sodium molbydate, pH 7.4). 45 uL of GR was added to each well and the plates were incubated for 15 min at room temperature.3H-dexamethasone solution was diluted to a concentration of 70 nM in assay buffer (7 nM final assay concentration) and 5 uL was added to each well. The samples were mixed for 5 min using a plate shaker at 700 rpm, before incubation for 2 h at room temperature,50 uL ice-cold charcoal solution.
- SARS-CoV-2 Mpro enzyme assay The activity of SARS-Cov-2 Mpro was determined in a Fluorescence Resonance Energy Transfer (FRET)-based enzymatic assay using FRET Substrate Dabcyl-KTSAVLQSGFRKM-E(Edans)-Amide. In brief, 5 pL of test compounds (concentrations ranging from 100 pM to 0.0017 pM) was preincubated with 5 pL of 20 nM (final concentration) Mpro enzyme for 30 min at 30 °C in an assay buffer containing 20 mM HEPES, 120 mM NaCI, 0.4 mM EDTA, and 4 mM DTT and 20% glycerol. Reaction was initiated by addition of 10 pL of 20 pM (final concentration) of FRET substrate (Dabcyl-KTSAVLQSGFRKM-E (Edans)-Amide). The reaction was incubated for 1 h and the resulting fluorescent intensity was measured at Ex=360 nm/Em=490 nm at 30 °C using a SPARK 20M plate reader (Tecan). Boceprevir was used a reference standard compound. pICso and pKi were determined using 4PL GraphPad Prism and data were represented as a mean n=2± SD.
- SPA Binding Assay The binding of potential ligands to RORγ is measured by competition with [3H] 25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA) binding assay. The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromotography. 15 ug/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 μM to 0.28 nM for 10 min at room temperature in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% Glycerol (Sigma Cat# G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat # RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer).
- Scintillation Proximity Assay (SPA The scintillation proximity assay (SPA) was run in white polystyrene flat-bottom 384-well plates (Greiner, cat. No. 781075). Assays were carried out in 40 i1 reaction volumes. Various concentrations of test ligands in 0.4 microlitres of DMSO were added to assay plates using an acoustic liquid dispenser. 4 nM purified N—(HN)6-GST-TCS-hRORγ (258-518) was mixed with 40 micrograms Yttrium oxide (YOx) glutathione SPA imaging beads in assay buffer (20 mM Tris, 150 mM NaCl, 10% Glycerol, 0.25% CHAPS, 1 mM TCEP) prior to adding 30 microlitres to test ligands. Assay plates were incubated for one hour at room temperature before adding 10 microlitres tritiated 2-(4-(ethylsulfonyl)phenyl)-N-(4-(2-(methoxymethyl)phenyl)thiophen-2-yl)acetamide to test plates in assay buffer (final concentration, 25 nM). Test plates were incubated for 16 hours and read using a LEADseeker Multimodality imaging instrument.
- Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 ??L. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3K?? assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 ??M PIP2, 2 ??M ATP, 0.5 ??Ci [??-33P]ATP, 3.4 nM PI3K??. Reactions were incubated for 120 min and terminated by the addition of 40 ??L SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer).
- Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 uL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 uM PIP2, 20 uM ATP, 0.2 uCi [gamma-33P] ATP, 4 nM PI3Kdelta. Reactions were incubated for 210 min and terminated by the addition of 40 uL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 uM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes.
- Time-Resolved Endpoint Proteolysis Assay Inhibitor IC50s at purified human autoBACE-2 were determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3x the desired final concentration in 1x BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO were pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1x BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30 C. The assay was initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1x BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C.
- Time-Resolved Endpoint Proteolysis Assay Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies).
- Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) Assay The assay measures the phosphorylation level of a biotinylated peptide substrate by the ASK1 kinase using HTRF detection (6.1). This is a competitive, time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay, based on HTRF KinEASE-STK manual from Cisbio (6.1). Test compound, 1 uM STK3 peptide substrate, 4 nM of ASK1 kinase are incubated with 10 mM MOP buffer, pH. 7.0 containing 10 mM Mg-acetate, 0.025% NP-40, 1 mM DTT, 0.05% BSA and 1.5% glycerol for 30 minutes then 100 uM ATP is added to start the kinase reaction and incubated for 3 hr. Peptide antibody labeled with 1x Eu3+ Cryptate buffer containing 10 mM EDTA and 125 nM Streptavidin XL665 are added to stop the reaction and phosphorylated peptide substrate is detected using Envision 2103 Multilabeled reader from PerkinElmer. The fluorescence is measured at 615 nm (Cryptate) and 665 nm (XL665) and a ratio of 665 nm/615 nm is calculated for each well.
- Time-Resolved Fluorescence Resonance energy transfer (TR-FRET) Immunoassay The assay measures the phosphorylation level of a biotinylated peptide substrate by the ASK1 kinase using HTRF detection. This is a competitive, time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay, based on HTRF KinEASE-STK manual from Cisbio. Test compound, 1 uM STK3 peptide substrate, 4 nM of ASK1 kinase were incubated with 10 mM MOP buffer, pH. 7.0 containing 10 mM Mg-acetate, 0.025% NP-40, 1 mM DTT, 0.05% BSA and 1.5% glycerol for 30 minutes then 100 uM ATP was added to start the kinase reaction and incubated for 3 hr. Peptide antibody labeled with 1xEu3+ Cryptate buffer containing 10 mM EDTA and 125 nM Streptavidin XL665 were added to stop the reaction and phosphorylated peptide substrate was detected using Envision 2103 Multilabeled reader from PerkinElmer. The fluorescence was measured at 615 nm (Cryptate) and 665 nm (XL665) and a ratio of 665 nm/615 nm was calculated for each well.
- hADAMTS-5 assay The basis for the assay is the cleavage of the substrate TBIS-1 (5 FAM-TEGEARGSVILLK (5TAMRA)K-NH2) (SEQ ID NO: 2) by human ADAMTS-5.For the dose response (10 point), 4 μL of a dilution series of compound (2 mM highest concentration, 1/5 dilution in DMSO further diluted 1 in 10 in water, corresponding to a final highest concentration of 20 μM), is transferred to 384 well Fluotrac 200 plate (Greiner, cat#781076) and incubated at room temperature for 30 min with a 26 μL buffer solution (50 mM Hepes pH7.5, 100 mM NaCl, 5 mM CaCl2, 0.1% CHAPS, 5% glycerol) containing hADAMTS-5 (0.5 ng/μL) (it will be appreciated by the skilled person that the potency read out is independent of the enzyme concentration).The reaction is initiated by adding to the assay plate TBIS-1 (10 μL, 4.5 μM, Anaspec) in the same buffer.Finally, the fluorescence is read on the Envision (Perkin Elmer) after an incubation of 60 min at Room Temperature (Excitation 485 nm, emission 530).
- kinase Assay The final concentration of DMSO is 5%. 10 μL of the B-Raf (V600E)-kinase solution are pipetted in (containing 0.5 ng B-Raf (V600E)-kinase in 20 mM Tris-HCl pH 7.5, 0.1 mM EDTA, 0.1 mM EGTA, 0.286 mM sodium orthovanadate, 10% glycerol, 1 mg/mL bovine serum albumin, 1 mM dithiothreitol) and the mixture is incubated for 24 h at RT under with shaking. The kinase reaction is started by the addition of 20 μL ATP solution [final concentration: 250 μM ATP, 30 mM Tris-HCl pH 7.5, 0.02% Brij, 0.2 mM sodium orthovanadate, 10 mM magnesium acetate, 0.1 mM EGTA, phosphatase cocktail (Sigma, # P2850, dilution recommended by the manufacturer), 0.1 mM EGTA] and 10 μL MEK1 solution [containing 50 ng biotinylated MEK1 (prepared from purified MEK1 according to standard procedure, e.g. with EZ-Link Sulpho-NHS-LC-Biotin reagent, Pierce, #21335) and carried out for 60 min at RT with constant shaking.
- BACE-1 Ki Assay (BACE-1 HTRF FRET Assay) The compounds of the invention were assessed for their ability to inhibit BACE-1 using the following assay. The resulting values are reported in the tables above.The following reagents were used in this assay. Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE-1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide.A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE-1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE-1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE-1 enzyme. Inhibition of BACE-1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE-1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 milisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined μm value of 8 μM for the QSY7-APPswe-Eu substrate at BACE-1.
- Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 hours with 1 mL of anti-FLAG resin (Sigma catalog #A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 μg/ml 3×FLAG peptide).The ability of new chemical matter to inhibit the ATR catalytic activity in this ATR/ATRIP complex was assessed using a Caliper-based assay. A 2× enzyme solution (i.e., 4 nM enzyme) was prepared using 1× Kinase Reaction Buffer (25 mM HEPES pH 8, 0.0055% Brij-35, 10 mM MnCl2, and 1 mM DTT). A 2× peptide solution was then prepared consisting of 10 uM FAM-labeled RAD17 peptide (GL Biochem, catalog #524315) in 1× Kinase Reaction Buffer supplemented with 2 μM ATP. 10 μL of the 2× enzyme solution was transferred to an assay plate containing 60 nL of test compound (from a 3× serial dilution) in 100% DMSO. Following a 30 minute incubation at 28° C., 10 μL of the 2× peptide solution was then transferred to the same assay plate. The reaction was allowed to incubate at 28° C. for 6 hours. After adding 30 μL of stop buffer (100 mM HEPES pH 7.5, 0.015% Brij-35, 0.2% Coating-3 Reagent (PerkinElmer, catalog # PN760050), and 50 mM EDTA), data were collected on a Caliper instrument.
- Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 hours with 1 mL of anti-FLAG resin (Sigma catalog #A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 μg/ml 3×FLAG peptide).The ability of new chemical matter to inhibit the ATR catalytic activity in this ATR/ATRIP complex was assessed using a Caliper-based assay. A 2x enzyme solution (i.e., 4 nM enzyme) was prepared using 1× Kinase Reaction Buffer (25 mM HEPES pH 8, 0.0055% Brij-35, 10 mM MnCl2, and 1 mM DTT). A 2x peptide solution was then prepared consisting of 10 uM FAM-labeled RAD17 peptide (GL Biochem, catalog #524315) in 1× Kinase Reaction Buffer supplemented with 2 μM ATP. 10 μL of the 2× enzyme solution was transferred to an assay plate containing 60 nL of test compound (from a 3× serial dilution) in 100% DMSO. Following a 30 minute incubation at 28° C., 10 μL of the 2× peptide solution was then transferred to the same assay plate. The reaction was allowed to incubate at 28° C. for 6 hours. After adding iL of stop buffer (100 mM HEPES pH 7.5, 0.015% Brij-35, 0.2% Coating-3 Reagent (PerkinElmer, catalog #PN760050), and 50 mM EDTA), data were collected on a Caliper instrument.
- HCMV Polymerase Scintillation Proximity Assay The assay conditions are the following: 10 mM HEPES pH 7.5, 25 mM KCl, 7.5 mM NaCl, 5 mM MgCl2, 0.2 mg BSA/mL, 1 mM TCEP, 1.5% glycerol, 2 μM dTTP, 90 nM 3H-dTTP (minor variations in concentration are possible due to specific activity of stock), 26 nM Poly(dA)/190 nM BioTEG-dT19; 5% DMSO. The assay volume is 30 μL. Each reagent is added at a 3× conc.: 10 μL a+10 μL b+10 μL c; a: compound diluted in 10 mM Hepes pH 7.5, 25 mM KCl, 5 mM MgCl2, 1 mM TCEP with 15% DMSO; b: enzyme (GST-UL54) in 10 mM Hepes pH 7.5, 25 mM KCl, 5 mM MgCl2, 22.5 mM NaCl, 4.5% Glycerol, 0.6 mg BSA/mL, 1 mM TCEP w/o DMSO (1 nM GST-UL54 is present in the assay); c: substrate in 10 mM Hepes pH 7.5, 25 mM KCl, 5 mM MgCl2, 1 mM TCEP, 6 μM dTTP, 270 nM 3H-dTTP, 78 nM Poly(dA)/570 nM BioTEG-dT19 w/o DMSO. To perform the assay, 10 μL enzyme solution is added to columns 2-12 and 14-24. The enzyme is substituted by the blank solution (b solution without enzyme) for columns 1 and 13 (blanks). The plate is centrifuged at 200×g for 30 sec. 10 μL of substrate solution is added to each well. The plate is centrifuged at 200×g for 30 sec. The plates are incubated at 37 °C. for 40 min. To stop the reaction, 25 μL of SPA beads (5 mg/mL in 0.5 M EDTA) are added and mixed by pipetting up and down. The plates are incubated at RT for at least 15 min. 35 μL of 5 M CsCl is added to the bottom of each well. TopSeal is applied to the plate and the plate is incubated at RT for at least 90 min prior to reading. The signal is read on TopCount plate reader (Perkin-Elmer) or equivalent.
- Axl Kinase Assay Certain compounds of formula (I) were tested for their potency in inhibiting Axl kinase. Inhibition of Axl kinase activity by a test compound was calculated by AlphaScreen (PerkinElmer 6760620M). Standard assay conditions included 1 ng of recombinant Axl kinase (SignalChem) with 3-10 ng Poly-(GT)-Biotin (Cisbio) in the assay buffer, i.e., 40 μM ATP (Sigma), 10 mM MOPs, pH7.0 (Sigma M-1254), 0.21 mM EDTA (Sigma E-6758), 0.5% glycerol (J. T Baker 2136-1), 1 mg/ml BSA (Bio-Rad 500-0007), 0.01% 2-mercaptoethanol (BDH 441433A), and 0.001% Brij35 (Sigma P1254) in a final volume of 25 μL. Reactions were incubated at 30° C. for 30 minutes and stopped by adding 5 μL of 50 mM EDTA. Product analysis was performed using the AlphaScreen kit and counted with Enspire Alpha (PerkinElmer). Screen values of inhibitors were determined after carrying out assays with eight serially diluted concentrations in duplication. Results were analyzed using linear regression software (GraphPad Prism 4; GraphPad Software Inc.).
- Binding Assay A stable CHO (Chinese hamster ovary) cell line expressing cloned human glucagon receptor was maintained as described (Chicchi, et. al. J Biol Chem 272, 7765-9 (1997); Cascieri, et. al. J Biol Chem 274, 8694-7 (1999)). To determine antagonistic binding affinity of compounds, 0.001-0.003 mg of cell membranes from these cells were pre-incubated with 0.100 mg WGA-coated PVT SPA beads (Amersham) for 20 minutes at room temperature in 25 μL of a buffer containing 50 mM Tris-HCl (pH 7.5), 5 mM MgCl2, 2 mM EDTA, 0.1% BSA and 3% glycerol in Costar 384 well plates with clear bottoms (#3706). Next, 25 μL of 125I-Glucagon (New England Nuclear, MA) (1×10−14 mol per well) and either 1 μL solutions of test compounds or 0.001 mM unlabeled glucagon or DMSO were added and mixed. After 4-12 hours incubation at room temperature, the radioactivity bound to the cell membranes was determined in a radioactive emission detection counter (Wallac-Microbeta).
- Enzyme Assay An on-bead solid phase homogeneous assay was used in a 384-well format to assess NS5B inhibitors (WangY-K, Rigat K, Roberts S, and Gao M (2006) Anal Biochem, 359: 106-111). The biotinylated oligo dT12 primer was captured on streptavidin-coupled imaging beads (GE, RPNQ0261) by mixing primer and beads in 1X buffer and incubating at room temperature for three hours. Unbound primer was removed after centrifugation. The primer-bound beads were resuspended in 3X reaction mix (20 mM Hepes buffer, pH 7.5, dT primer coupled beads, poly A template, 3H-UTP, and RNAse inhibitor (Promega N2515)). Compounds were serially diluted 1:3 in DMSO and aliquoted into assay plates. Equal volumes (10 uL) of water, 3X reaction mix, and enzyme in 3X assay buffer (60 mM Hepes buffer, pH 7.5, 7.5 mM MgCl2, 7.5 mM KCl, 3 mM DTT, 0.03 mg/mL BSA, 6% glycerol) were added to the diluted compound on the assay plate. Final concentration of components in 384-well assay: 0.36 nM template, 15 nM primer.
- Enzyme Assay An on-bead solid phase homogeneous assay was used in a 384-well format to assess NS5B inhibitors (WangY-K, Rigat K, Roberts S, and Gao M (2006) Anal Biochem, 359: 106-111). The biotinylated oligo dT12 primer was captured on streptavidin-coupled imaging beads (GE, RPNQ0261) by mixing primer and beads in 1x buffer and incubating at room temperature for three hours. Unbound primer was removed after centrifugation. The primer-bound beads were resuspended in 3x reaction mix (20 mM Hepes buffer, pH 7.5, dT primer coupled beads, poly A template, 3H-UTP, and RNAse inhibitor (Promega N2515)). Compounds were serially diluted 1:3 in DMSO and aliquoted into assay plates. Equal volumes (5 uL) of water, 3x reaction mix, and enzyme in 3x assay buffer (60 mM Hepes buffer, pH 7.5, 7.5 mM MgCl2, 7.5 mM KCl, 3 mM DTT, 0.03 mg/mL BSA, 6% glycerol) were added to the diluted compound on the assay plate. Final concentration of components in 384-well assay: 0.36 nM template, 15 nM primer.
- Enzyme Assay Materials: All chemicals are available from Sigma-Aldrich (St. Louis, Mo.) except for IMAP reagents (reaction buffer, binding buffer, FL-GMP and IMAP beads), which are available from Molecular Devices (Sunnyvale, Calif.).Assay: The following phosphodiesterase enzymes may be used: 3',5'-cyclic-nucleotide-specific bovine brain phosphodiesterase (Sigma, St. Louis, Mo.) and recombinant full length human PDE1A and PDE1B (r-hPDE1A and r-hPDE1B, respectively) which may be produced e.g., in HEK or SF9 cells by one skilled in the art. The PDE1 enzyme is reconstituted with 50% glycerol to 2.5 U/ml. One unit of enzyme will hydrolyze 1.0 umole of 3',5'-cAMP to 5'-AMP per min at pH 7.5 at 30 C. One part enzyme is added to 1999 parts reaction buffer (30 uM CaCl2, 10 U/ml of calmodulin (Sigma P2277), 10 mM Tris-HCl pH 7.2, 10 mM MgCl2, 0.1% BSA, 0.05% NaN3) to yield a final concentration of 1.25 mU/ml. 99 ul of diluted enzyme solution is added into each assay.
- HIF-1alpha transactivation assays HaCaT-EPO-Luc cells were maintained at 37° C. in a humidified atmosphere containing 5% CO2 in DMEM supplemented with 10% fetal calf serum (FBS), and 1% (v/v) penicillin/streptomycin. The cells (1×105/well in 24-well plates) were seeded the day before the assay and then stimulated with increasing concentrations of either Cannabidiol (CBD), VCE-004 or compounds II to X. After six hours of stimulation the cells were lysed in 25 mM Tris-phosphate pH 7.8, 8 mM MgCi2, 1 mM DTT, 1% Triton X-100, and 7% glycerol during 15 min at RT in a horizontal shake. Luciferase activity was measured in the cell lysates as indicated for NIH3T3-EPO-Luc cells. The RLUs are calculated and the EC50 and IRA (Intrinsic relative activity) values in both cell lines were determined relative to 150 μM deferoxamine (DFX) using the following equation: IRA coefficient=(EC50-DFX×Emax)/(EC50×Emax-DFX), where EC50 and Emax denote EC50 and Emax of the agonist, and EC50-DFX and Emax-DFX denote EC50 and Emax values of the standard agonist DFX.
- HTRF FRET Assay BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies).
- HTRF FRET Assay The compounds of the invention were determined to be potent inhibitors of BACE-1 using the following assay.The following reagents were used in this assay. Na+-Acetate pH 5.0; 1% Brij-35; Glycerol; Dimethyl Sulfoxide (DMSO); Recombinant human soluble BACE-1 catalytic domain (>95% pure); APP Swedish mutant peptide substrate (QSY7-APPswe-Eu): QSY7-EISEVNLDAEFC-Europium-amide.A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE-1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE-1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE-1 enzyme. Inhibition of BACE-1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.
- Inhibition Assay A rapid plate DNA synthesis assay was performed using optimized conditions. Briefly, a 1.2:1 ratio of a 20-mer oligonucleotide primer (5′-GCGAATGAATGACCGCTGAC-3′, SEQ ID No. 1) and a 5′-end biotinylated 100-mer oligonucleotide template (5′-Biotin-AGCACTATTGACATTACAGAGTCGCCTTGGCTCTCTGGCTGTTCGTTGCGGGCTCCGCG TGCGTTGGCTTCGGTCGTCCCGTCAGCGGTCATTCATTGGC-3′) were annealed and loaded into a 96-well microtiter streptavidin-coated plate (Streptawell plates, Roche Applied Science, Indianapolis, Ind., USA) at 5 pmol/well. The wells were incubated at 37 C for 90 min, and washed with 100 L PBS. The reaction was conducted in low salt buffer (20 mM Tris-HCl pH 7.4, 3 mM MgCl2, 0.1 mM EDTA, 0.5 mM DTT, 2% glycerol, 40 ug/mL BSA, 5 uM dNTPs, 1 uM digoxigenin-11-2′-deoxyuridine-5′-triphosphate (DIG-dUTP, Roche Applied Science) with 1 μL vaccinia infected cell lysate or 1 uL of in vitro translated E9 DNA polymerase. The reaction plates were incubated at 37° C
- Inhibition of Caspase Activity Assay Caspase-1 was diluted to 10 U/μl in assay buffer consisting of 50 mM HEPES, pH 7.4, 100 mM NaCl, 0.1% CHAPS, 1 mM EDTA, 10% glycerol and 10 mM DTT.Reaction Conditions:45 μl of assay buffer was added into ½ volume microtiter plate. The plate was allowed to equilibrate to assay temperature. 5 μl of Caspase-1 (10 U/μl) was added to each appropriate well. Two 2 blank wells containing just assay buffer without Caspase-1 were included on the plate.The reaction was started by the addition of 50 μl Ac-YVAD-pNA substrate, for a final substrate concentration of 200 μM. The reaction was continuously monitored at 405 nm.The data was graphed as OD405 nm vs time, and the slope was determined over the linear portion of the curve. The rates in OD/min were converted to substrate/min using an extinction coefficient for p-nitroaniline of 10,500 M-1 cm-1, and were adjusted for pathlength of sample. Similarly, assays were conducted for Caspase-3, Caspase-8 and Caspase-9.
- Inhibitory Activity Assay The MAO-B inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK. A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 uL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1-(test compound count-blank)/(control-blank))x100The count of the MAO-B enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-B enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- Kinase Assay Pharmacol 2002, 62 58-62) The compounds named in the specified Examples were tested as follows for inhibition of ALK-5 autophosphorylation activity and of the ALK-5 phosphorylation of α-Casem Materials. Buffer 50 mM HEPES, pH 76, with 10 mM NaCI, 10 mM MgCI2, and 1 mM DTT GST-ALK-5 protein - 0 44 mg/ml (roughly 7 μM stock) A 1 350 dilution gives a 20 nM stock, which translates to 2 nM final in assay Human ALK-5 was expressed in Sf9 insect cells infected with Bacul ovirus expressing a ALK-5 truncation sequence (amino acids H149 -M503), fused at the N-terminus to Glutathione S-transferase GST, in a pFastBac vector (Invitrogen) The cells were disrupted by sonication at 4 0C The lysate was centrifuged at 40,000 x g for 45 minutes, and the supernantant applied to a 10 ml column of Glutathione Sepharose 4 Fast Flow (AmershamBioscienses) equilibrated with 100 mM Tπs-HCI pH 76 buffer containing 300 mM NaCI, 10% glycerol, 1 % NP40, 2 mM dithiothreitol (DTT) and one Protease...
- MAO-B Inhibitory Activity The MAO-B inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula.inhibitory rate (%)=(1−(test compound count−blank)÷(control−blank))×100The count of the MAO-B enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-B enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- MAO-B Inhibitory Assay The MAO-B inhibitory activity evaluation described below followed the protocol of MAO-Glo (registered trademark) Assay of Promega KK.A test compound dissolved in DMSO was added to a reaction solution (100 mM HEPES (pH 7.5), 5% glycerol, 10% DMSO) containing MAO-B enzyme (Sigma-Aldrich Co. LLC.), and the mixture was reacted at room temperature for 15 min. MAO substrate (Promega KK) was added to start the reaction. After reaction at room temperature for 60 min, Luciferine detection reagent (Promega KK) (50 μL) was added to terminate the reaction. After reaction at room temperature for 20 min with stirring, the luminescence was measured by Envision (PerkinElmer). The MAO-B inhibitory rate (%) of the test compound was calculated by the following formula. inhibitory rate (%)=(1−(test compound count−blank) (control−blank))×100The count of the MAO-B enzyme reaction mixture under compound non-addition conditions is indicated as control, and the count under compound non-addition and MAO-B enzyme non-addition conditions is indicated as blank. A concentration necessary for achieving 50% inhibitory rate was taken as IC50 value.
- Modulation of Endogenous Assay The human leukemia Jurkat T-cell line was maintained in RPMI 1640 (Cambrex) supplemented with 10% fetal calf serum and 50 ng/ml Geutamycin. Before treatment cells were washed, resuspended at a density of about 106 cells/milliliter in medium containing 1% fetal calf serum and incubated in the presence of indicated mounts of drug for two hours. Cells were recovered by centrifugation, lysed using a hypotonic buffer (20 mM Tris/HCl pH 7.4; 2 mM EDTA; 5 mM EGTA; 10 mM mercaptoethanol; 10 mM NaF; 1 uM Okadaic acid; 10% v/v glycerol; 0.05% NP-40; 1% Protease Inhibitor Cocktail) and protein from the cleared lysate was diluted to 1 microgram per microliter in Assay Dilution Buffer (ADB; 20 mM MOPS, pH 7.2, 25 mM β-glycerolphosphate, 5 mM EGTA, 1 mM sodium orthovanadate and 1 mM dithiothreitol). To 20 microliters of diluted protein was added 10 microliters of substrate peptide (RRRDDDSDDD, dissolved in ADB at a concentration of 1 mM) and 10 microliters of PKA Inhibitor cocktail (Upstate).
- Omnia Assay Briefly, 10x stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13x ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1x kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10x stock, KB002A) and 0.2 mM DTT (DS001A). 5 uL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25° C. with a 0.5 uL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 uL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics.
- Scintillation Proximity Assay PI3K-gamma:The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 uL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kgamma assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 uM PIP2, 2 uM ATP, 0.5 uCi [gamma-33P] ATP, 13 nM PI3Kgamma. Reactions were incubated for 120 min and terminated by the addition of 40 uL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay PI3Kdelta: The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 uL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kdelta assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 uM PIP2, 2 uM ATP, 0.5 uCi [gamma-33P] ATP, 3.4 nM PI3Kdelta. Reactions were incubated for 120 min and terminated by the addition of 40 L SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 uL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 uM PIP2, 20 uM ATP, 0.2 uCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 uL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 uM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer).
- Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 uL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 uM PIP2, 20 uM ATP, 0.2 uCi [gamma-33P]ATP, 4 nM PI3Kdelta. Reactions were incubated for 210 min and terminated by the addition of 40 uL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 uM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer).
- TR-FRET Assay Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2× Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 pM, and PI3Kγ at 2 nM. The compounds were added to the assay solution and incubated for 30 minutes at 25° C. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIPS, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 μs delay and 500 μs read window).
- Time-Resolved Endpoint Proteolysis Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3x the desired final concentration in 1ÿBACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1ÿBACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1xBACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay.
- Time-Resolved Endpoint Proteolysis Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% fin
- Time-Resolved Endpoint Proteolysis Assay Inhibitor compounds, prepared at 3× the desired final concentration in 1× BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1× BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1× BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) Assay The test detects the phosphorylation of the substrate GFP-4EBP1 using a terbium-labelled antibody that is specific for the phospho-Thr46 epitope. Binding of the Tb-antibody to the phosphorylated GFP peptide allows the transfer of energy from Tb, excited at 340 nm, to GFP with an increase in the fluorescence emission of the GFP at 520 nm. The test is performed in 96-well format (Corning/Costar 96 black flat-bottomed half-wells plate, ref. 3694) in a total volume of 30 ul. To 1 ul of inhibitor in 100% DMSO are added (final concentrations) 400 nM of GFP-4EBP1 (Invitrogen PV4759), 8 uM of ATP, 200 ng/ml of enzyme (human recombinant aa mTOR 1360-2549, Invitrogen PV4753) in a buffer of HEPES 50 mM pH 7.5, EGTA 1 mM, MnCl2 10 mM, BSA 0.1 mg/ml, glycerol 0.5%, NV-10 0.1 mg/ml, DTT 2 mM. The mixture is incubated for 30 minutes at room temperature. 10 ul of solution are taken up and the reaction is quenched by adding 10 ul of Tb-antibody solution (Invitrogen PV4757)/EDTA.
- Time-Resolved Fluorescence Resonance Energy transfer (TR-FRET) Assay Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2× Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, 1% (v/v) DMSO at the following concentrations for each isoforms: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 pM, and PI3Kγ at 2 nM. After an assay reaction time of 30 minutes at 25° C., reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 10lps delay and 500 μs read window).
- Urease Inhibition Assay Briefly, 50 mL broth cultures (2.0 × 10^8 CFU/mL) were centrifuged (5000g, 4°C)to collect the bacteria, and after washing twice with phosphate-buffered saline (pH 7.4), the H. pylori precipitation was stored at −80°C. H. pylori was returnedto room temperature, and after the addition of 3 mL of distilled water and protease inhibitors, sonication was performed for 60 s. Following centrifugation(15,000g, 4°C), the supernatant was desalted through SephadexG-25 column (PD-10 columns, Amersham-Pharmacia Biotech, Uppsala, Sweden). The resultant crude urease solution was added to an equal volume of glycerol and stored at 4°C until use in the experiment. The mixture, containing 25 μL (4U) of H. pylori urease (100 mM HEPES, pH 6.8) and 25 μL of the test compounds of various concentrations, was preincubated for 3 h at room temperature in a 96-well assay plate. After preincubation, 0.2 mL of 100 mM HEPES (pH 6.8) buffer containing 500 mM urea and 0.002% phenol red were added and incubated at 37°C.
- Fluorescence Polarization Assay Expression and purification of the BRD4(I) recognition domain: colonies of newly transformed plasmid DNA from E. coli BL21(DE3)-condon plus-RIL cells were cultivated in 50 mL of Terrific Broth medium containing 50 μg/mL kanamycin and 34 μg/mL chloramphenicol at 37° C. overnight (starting culture). The starting culture was then diluted 100-fold in 1 L of fresh TB medium and the cells were grown at 37° C. to an optical density of about 0.8 at OD600 and then the temperature was lowered to 16° C. When the system was equilibrated at 16° C., the optical density at OD600 was approximately 1.2, and protein expression was induced with 0.2 mmol of isopropyl-β-D-thiogalactopyranoside (IPTG) overnight at 16° C. Bacteria were harvested by centrifugation (4000×g, 20 minutes, 4° C.) and stored as a pellet at −80° C. The cells expressing His 6-tagged protein was resuspend in lysis buffer [50 mmol 4-hydroxyethylpiperazineethanesulfonic acid (HEPES), 25° C., pH 7.5, 500 mmol NaCl, 10 mmol imidazole, 5% glycerol and freshly added 0.5 mmol of tris(2-carboxyethyl)phosphine hydrochloride (TCEP) and 1 mmol of phenylmethanesulfonyl fluoride (PMSF)] and lysed at 4° C. using JN 3000PLUS high pressure homogenizer (JNBIO-Guangzhou, China). The lysate was clarified by centrifugation (12,000×g for 1 hour at 4° C.) and applied to a nickel-nitriloacetate agarose column. The column was washed once with 50 mL of wash buffer containing 30 mmol of imidazole. The protein was eluted using imidazole in an elution buffer in a stepwise elution (100-250 mmol imidazole in 50 mmol HEPES, 25° C., pH 7.5, 500 mmol NaCl, 5% glycerol). All fractions were collected and monitored by SDS-polyacrylamide gel electrophoresis (Bio-Rad Criterion TM Precast Gels, 4-12% Bis-Tris, 1.0 mm, from Bio-Rad, CA). After 1 mmol of dithiothreitol (DTT) was added, the eluted proteins were treated with tobacco plaque virus (TEV) protease overnight at 4° C. to remove the His6 tag. The protein was concentrated and further purified by size exclusion chromatography on a Superdex 75 16/60 HiLoad gel filtration column. The samples were monitored by SDS-polyacrylamide gel electrophoresis and concentrated to 8-10 mg/mL with gel filtration buffer, 10 mmol Hepes pH 7.5, 500 mM NaCl, 1 mmol DTT, and used for protein binding assays and crystallization.
- AlphaScreen Assay Compounds of the invention were tested for ACK1 inhibition activity. 1 uL compounds prepared at 15× in 4 mM DMSO were combined with 9 uL ATP solution in assay buffer containing 50 mM Hepes, 1% glycerol, 1.665 mM MnCl2 and Poly-(GT)-Biotin (Cisbio #61GT0BLD, 1:1500 dilution) in ProxiPlate-384 Plus plate (PerkinElmer #6008280). Final DMSO concentration was 0.25% with an ATP final concentration of 100 uM. The reaction was started by adding 5 uL ACK1 solution (Carna, 15 pg/uL final in assay) in an enzyme buffer containing 50 mM Hepes, 0.24 mM EGTA, 0.024% Brij-35, 3 mM DTT, 0.01% BSA. Reaction was allowed to occur for 20 min., shaking, at RT. Anti PT66 acceptor beads and Streptavidin donor beads (PerkinElmer #6760602R) were prepared by adding each at 1:160 dilution in a detection buffer containing 25 mM Tris-HCl, 250 mM NaCl, 100 mM EDTA, 0.25% BSA. Prepared beads were added to assay plate at 5 uL well and allowed to incubate protected from light, shaking, for 2 hrs at RT. Plates were read on AlphaQuest reader.
- Binding Assay Test A1: Briefly, in Test A1 the assay was run in 384 well format in 10 mM Tris-HCl, pH 7.5, 0.5 mM EDTA 20 mM NaMoO4, 0.1 mM DTT and 10% glycerol at rt. Compounds were tested in a 7 (Test A1) or 10 (Test A2) concentration response curve ranging from 10 nM to 10 μM (Test A1) or 1 nM to 37 μM (Test A2). Compounds were spotted at the bottom of a well of a 384-well PE Opti-Plate to yield final DMSO concentrations in the assay of 2%. Pre-made MBP-MR/P23 lysate: 3H-aldosterone mix (final assay concentration 7 μg/mL MBP-MR LBD/P23 lysate; 5 nM aldosterone) was added onto the top of the spotted compound and preincubated for 1 h at RT. After 1 h an equal volume anti-rabbit SPA beads coupled with rabbit anti-MBP were added to the assay mixture and incubated for 3 hrs at rt. The inhibition of the scintillation signal by displacement of the bound 3H-aldosterone by test compounds is measured by scintillation counting using a Microbeta Trilux (Wallac).
- Binding Assay Test A2: Briefly, in Test A1 the assay was run in 384 well format in 10 mM Tris-HCl, pH 7.5, 0.5 mM EDTA 20 mM NaMoO4, 0.1 mM DTT and 10% glycerol at rt. Compounds were tested in a 7 (Test A1) or 10 (Test A2) concentration response curve ranging from 10 nM to 10 μM (Test A1) or 1 nM to 37 μM (Test A2). Compounds were spotted at the bottom of a well of a 384-well PE Opti-Plate to yield final DMSO concentrations in the assay of 2%. Pre-made MBP-MR/P23 lysate: 3H-aldosterone mix (final assay concentration 7 μg/mL MBP-MR LBD/P23 lysate; 5 nM aldosterone) was added onto the top of the spotted compound and preincubated for 1 h at RT. After 1 h an equal volume anti-rabbit Imaging beads coupled with rabbit anti-MBP were added to the assay mixture and incubated for >8 h at rt. The inhibition of the scintillation signal by displacement of the bound 3H-aldosterone by test compounds is measured by scintillation counting using a CCD camera detection using a LEADseeker (PerkinElmer).
- CONFA Assay Confirmatory Assay (CONFA) used as a secondary screen for confirming the mechanism of action of compounds identified as hits using the ALA assay. The assay is performed using a similar procedure as ALA except that it utilizes SDS-PAGE for visualization and quantification of tau monomer and aggregated species (dimer, trimer, tetramer, pentamer, etc.). Only a single construct of tau without epitope tags is necessary, but the assay can use the same target prepared for the ALA assay also.For the CONFA assay, Tau target (300 nM) was prepared in buffer (Tris-HCl pH 7.4) and was incubated at room temperature for 3 hours with vehicle control (DMSO) and a dose range of a compound of the disclosure (0.098 uM-50 uM). Samples were mixed with an equal volume of 2×SDS sample buffer (4% SDS, 20% glycerol, 0.004% bromphenol blue, 125 mM Tris HCl, pH 7.0) to resolve tau monomer and disulfide-linked oligomers on 4-20% gradient polyacrylamide gels (Biorad) along with positive control (non-oligomerized tau target). The gels were stained with Oriole Fluorescent Gel Stain (BioRad) and imaged using the FluorChem R system (Protein Simple). AlphaView software (Protein Simple) was used for quantification of tau monomer and oligomers.
- Enzyme Assay Assay: The following phosphodiesterase enzymes may be used: 3′,5′-cyclic-nucleotide-specific bovine brain phosphodiesterase (Sigma, St. Louis, Mo.) (predominantly PDE1B) and recombinant full length human PDE1A and PDE1B (r-hPDE1A and r-hPDE1B respectively) which may be produced e.g., in HEK or SF9 cells by one skilled in the art. The PDE1 enzyme is reconstituted with 50% glycerol to 2.5 U/ml. One unit of enzyme will hydrolyze 1.0 μmole of 3′,5′-cAMP to 5′-AMP per min at pH 7.5 at 30° C. One part enzyme is added to 1999 parts reaction buffer (30 μM CaCl2, 10 U/ml of calmodulin (Sigma P2277), 10 mM Tris-HCl pH 7.2, 10 mM MgCl2, 0.1% BSA, 0.05% NaN3) to yield a final concentration of 1.25 mU/ml. 99 μl of diluted enzyme solution is added into each well in a flat bottom 96-well polystyrene plate to which 1 μl of test compound dissolved in 100% DMSO is added. The compounds are mixed and pre-incubated with the enzyme for 10 min at room temperature.
- Enzyme Assay Assay: The following phosphodiesterase enzymes may be used: 3′,5′-cyclic-nucleotide-specific bovine brain phosphodiesterase (Sigma, St. Louis, Mo.) and recombinant full length human PDE1A and PDE1B (r-hPDE1A and r-hPDE1B, respectively) which may be produced e.g., in HEK or SF9 cells by one skilled in the art. The PDE1 enzyme is reconstituted with 50% glycerol to 2.5 U/ml. One unit of enzyme will hydrolyze 1.0 μmole of 3′,5′-cAMP to 5′-AMP per min at pH 7.5 at 30° C. One part enzyme is added to 1999 parts reaction buffer (30 μM CaCl2, 10 U/ml of calmodulin (Sigma P2277), 10 mM Tris-HCl pH 7.2, 10 mM MgCl2, 0.1% BSA, 0.05% NaN3) to yield a final concentration of 1.25 mU/ml. 99 μl of diluted enzyme solution is added into each well in a flat bottom 96-well polystyrene plate to which 1 μl of test compound dissolved in 100% DMSO is added. The test compounds are mixed and pre-incubated with the enzyme for 10 min at room temperature.
- FRET Assay The protocol is a modified FRET-based assay (v_02) from In Vitro Resistance Studies of HCV Serine Protease Inhibitors, 2004, JBC, vol. 279, No. 17, pp 17508-17514. Inherent potency of compounds was assessed against A156S, A156T, D168A, and D168V mutants of the HCV NS3/4A 1b protease enzyme as follows: 10× stocks of NS3/4A protease enzyme from Bioenza (Mountain View, Calif.) and 1.13× 5-FAM/QXL™520 FRET peptide substrate from Anaspec (San Jose, Calif.) were prepared in 50 mM HEPES, pH 7.8, 100 mM NaCl, 5 mM DTT and 20% glycerol. 5 μL of each enzyme were pre-incubated in a Corning (#3573) 384-well, black, non-treated microtiter plate (Corning, N.Y.) for 30 min at 25° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Protease reactions were started with the addition of 45 μL of the FRET substrate and monitored for 120 minutes at λex487/λem514 through Quad monochromoters in a Synergy4 plate reader from BioTek (Winooski, Vt.).
- In Vitro Enzyme Activity and Drug Binding Ub-charging of E2 enzyme was performed for 90 min at 30° C. in a reaction containing 0.1 μM GST-E1, 3.3 μM E2/UbcH7, 10 μM FLAG-Ub and 0.188 μM PINK1 (all R&D systems). In a separate reaction 0.75 μM Parkin (Ubiquigent) was preincubated with 20 μM compound 4 (or equal volume of DMSO). Both reactions were diluted in Ub buffer (final concentration: 20 mM HEPES pH 7.2, 10 mM MgCl2, 0.1 mM EGTA, 500 μM TCEP and 10% ATP regeneration system (20 mM HEPES pH 7.6, 10 mM ATP, 300 mM phosphocreatine, 10 mM MgCl2, 10% glycerol, 1.5 mg/mL creatine phosphokinase (all Sigma Aldrich))). 1 U Apyrase (Sigma) was added per 9 μL reaction and both reactions were combined and incubated for an additional 30 min. 100 μL of 1×LDS buffer was added per 10 μL reaction and samples were split for −/+DTT (20 mM final).
- KDM4C Enzymatic Screening Assay High-throughput MS assays were carried out using truncated KDM4C in 384-well V-bottom polypropylene plates (Greiner, Inc.). His-tagged recombinant KDM4C (1-350) was overexpressed and purified in-house from Escherichia coli BL21(DE3) to near-homogeneity. The demethylation reaction buffer contained 50 mM Tris-HCl, pH 7.5, 0.01% Triton X-100, 5% glycerol, 1 mM sodium ascorbate (Sigma), 5 μM 2-OG (Sigma) and 20 μM Fe2(NH4)2(SO4)2 (Sigma). Compounds were added to the plates from 10 mM DMSO stocks either as mixtures of eight compounds for screening (25 nl each, 10 μM final) or as serial dilutions of single compounds for IC50 determinations. Additional DMSO was added as a backfill (final DMSO: 0.8% (vol/vol)) using a LabCyte Echo 550. In 25-μl demethylation reactions, 400 nM recombinant KDM4C and 20 μM H3K9me3 peptide (1-21 amino acids, New England Peptide) were incubated with compounds for 10 min, and then 2-OG and Fe2(NH4)2(SO4)2 were added to initiate the reaction
- Kinase Profile Screening Assay Briefly, according to the requirements of different kinase reactions, 0.2 μL test compound (50 μM, dissolved in dimethyl sulfoxide (DMSO)) is added to reaction buffer containing specific kinase (the buffer system containing 20 mM MOPS, 1 mM EDTA, 0.01% Brij-35, 5% Glycerol, 0.1% β-mercaptoethanol, 1 mg/mL BSA, or 50 mM TRIS, 0.1 mM EGTA, 0.1 mM Na3VO4, 0.1% β-mercaptoethanol, 1 mg/mL BSA, based on the type of kinase used). Subsequently, a kinase specific substrate at a final concentration of 50 μM (specific substrate used for specific kinase), 10 mM Mg Acetate and isotope-labeled γ-33P ATP (radio-activity of about 500 cpm/pmol) are sequentially added to a total volume of 10 μL for the reaction system. After incubation at room temperature for 40 min, the reaction is terminated by adding 3% phosphoric acid solution. The mixture is then transferred to a filter-type low temperature spray dryer (P30 filtermat), and washed by 75 mM phosphoric acid solution for 3 times and by methanol once. After drying, radio-activity is detected.
- Kinetic Inhibition Assay Purified CtBP2 in 50% glycerol was added to 150 μM NADH and variable amounts of MTOB and HIPP in buffer containing 25 mM HEPES, pH 7.1, 25 mM potassium chloride, and 1mM DTT. The final concentration of CtBP was 40 μg/mL (986 nM) per reaction. HIPP was dissolved in DMSO (1% total volume). Final MTOB concentrations were the following: 36, 24, 12, 8, 4, 2, 1, and 0 μM for 0 μM HIPP; 64, 48, 24, 12, 8, 4, 2, and 0uM for 500nM HIPP; 80, 64, 48, 24, 12, 8, 4, and 0 μM for 1 μM HIPP; 96, 80, 64, 48, 36, 24, 12, and 0 μM for 2 μM HIPP. Reaction components wereadded to 96-well UV-Star Microplates (Greiner Bio-One). Upon addition of CtBP,reactions were mixed vigorously and immediately read by a Synergy H1 microplatereader (BioTek). Absorbance was recorded at A=340nm every 7 seconds for 7 minutes at 25°C to measure CtBP dehydrogenase function (NADH, but not NAD+ absorbs light at 340nm).
- Mer Kinase Assay Certain compounds of formula (I) were tested for their potency in inhibiting Mer kinase. Inhibition of Mer kinase activity by a test compound was calculated by AlphaScreen (PerkinElmer 6760620M). Standard assay conditions included 2 ng of recombinant Mer kinase (SignalChem) with 5 ng Poly-(GT)-Biotin (Cisbio) in the assay buffer, i.e., 10 μM ATP (Sigma), 8 mM MOPs, pH7.0 (Sigma M-1254), 0.2 mM EDTA (Sigma E-6758), 0.5% glycerol (J. T Baker 2136-1), 0.1 mg/ml BSA (Bio-Rad 500-0007), 0.01% 2-mercaptoethanol (BDH 441433A), 0.001% Brij35 (Sigma P1254), 10 mM MgCl2, and 10 mM MnCl2 in a final volume of 25 μL. Reactions were incubated at 30° C. for 30 minutes and stopped by adding 5 μL of 50 mM EDTA. Product analysis was performed using the AlphaScreen kit and counted with Enspire Alpha (PerkinElmer). Screen values of inhibitors were determined after carrying out assays with each compound at serially diluted concentrations in duplication. Results were analyzed using linear regression software (GraphPad Prism 4; GraphPad Software Inc.).
- Met Kinase Assay Certain compounds of formula (I) were tested for their potency in inhibiting Met kinase. Inhibition of Met kinase activity by a test compound was calculated by AlphaScreen (PerkinElmer 6760620M). Standard assay conditions included 1 ng of recombinant Mer kinase (SignalChem) with 3 ng Poly-(GT)-Biotin (Cisbio) in the assay buffer, i.e., 10 μM ATP (Sigma), 8 mM MOPs, pH7.0 (Sigma M-1254), 0.2 mM EDTA (Sigma E-6758), 0.5% glycerol (J. T Baker 2136-1), 0.1 mg/ml BSA (Bio-Rad 500-0007), 0.01% 2-mercaptoethanol (BDH 441433A), 0.001% Brij35 (Sigma P1254), 10 mM MgCl2, and 10 mM MnCl2 in a final volume of 25 μL. Reactions were incubated at 30° C. for 30 minutes and stopped by adding 5 μL of 50 mM EDTA. Product analysis was performed using the AlphaScreen kit and counted with Enspire Alpha (PerkinElmer). Screen values of inhibitors were determined after carrying out assays with each compound at serially diluted concentrations in duplication. Results were analyzed using linear regression software (GraphPad Prism 4; GraphPad Software Inc.).
- PI3Kδ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer).
- PI3Kδ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 M ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- PI3K-γ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay Example A3: The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 LM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay PI3Kδ Assay A3: The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay PI3Kδ:The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay To determine the affinity of the compounds of the present invention a SPA is used. The assay is run in a 384-plate format (OptiPlate-384) where each well contains a mix of 5 μL of test compound, 5 μL NR1s1s2 (ligand binding domains of the NMDA receptor, MW 35.6 kDa, 0.075 ug/well final), 5 μL [3H]-MDL-105,519 (radiolabelled, high affinity N-methyl-D-aspartate (NMDA) glutamate receptor antagonist at the glycine site, final concentration 5 nM, Kd=1.3 nM), 5 μL streptavidin coated imaging beads (Perkin Elmer cat. No.: RPNQ0273, 8 ug/well). The assay buffer contains 100 mM HEPES-NaOH, 150 mM NaCl, 1 mM EDTA, 10% glycerol at pH 7.4 in ultra-pure water. Non-specific binding is defined by inclusion of 10 μM L-689,560 (highly potent NMDA antagonist) and total binding by 1% DMSO. Following 30 minutes incubation in the dark (shaker, Multi-microplate Genie), the SPA beads are allowed to settle for 3 hours after which the signal is read on a Viewlux instrument (Perkin Elmer). Normalized data are used to calculate Ki values.
- Kinase Assay ALK-5 kinase assay methods have been described in the art (see e.g., Laping et al. (2002) Mol. Pharmacol. 2002; 62: 58-62). The compounds named in the specified Examples were tested as follows for inhibition of ALK-5 autophosphorylation activity and of the ALK-5 phosphorylation of α-Casein.Materials: Buffer. 50 mM HEPES, pH 7.6, with 10 mM NaCl, 10 mM MgCl2, and 1 mM DTT. GST-ALK-5 protein—0.44 mg/ml (roughly 7 μM stock). A 1:350 dilution gives a 20 nM stock, which translates to 2 nM final in assay. Human ALK-5 was expressed in Sf9 insect cells infected with Baculovirus expressing a ALK-5 truncation sequence (amino acids H149-M503), fused at the N-terminus to Glutathione S-transferase GST, in a pFastBac vector (Invitrogen). The cells were disrupted by sonication at 4° C. The lysate was centrifuged at 40,000×g for 45 minutes, and the supernatant applied to a 10 ml column of Glutathione Sepharose 4 Fast Flow (Amersham Bioscienses) equilibrated with 100 mM Tris-HCl pH 7.6 buffer containing 300 mM NaCl, 10% glycerol, 1% NP40, 2 mM dithiothreitol (DTT) and one Protease Inhibitor complete EDTA-free tablet per 50 ml (Roche). The column was washed with 5 column volumes of 50 mM Tris HCl pH 8.0 containing 150 mN NaCl, 10% glycerol, 2 mM DTT and one Protease Inhibitor complete EDTA-free tablet per 100 ml. The column was eluted with wash buffer containing 8 mM reduced glutathione. Fractions were collected and dialyzed overnight in 20 mM Tris HCl pH 8.0 containing 10% glycerol, 150 mM NaCl, 2 mM DTT and 1 mM 4-(2-aminoethyl)-bezenesulfonylfluoride.HCl (AEBSF) (Sigma) at 4° C. α-Casein (Sigma, #C8032) is made up at 2 mM in Buffer (50 mg/ml). Cold ATP contains 10 μM cold ATP (from a 10 mM stock in Buffer). Hot ATP consists of 0.5 μCi/well □-33P-ATP (Amersham, AH9968) in Buffer. Assay Buffer—Per 10 ml Buffer 1 ml of 500 mM HEPES (pH 7.6) 20 μl of 5 M NaCl 100 μl of 1 M MgCl2 10 μl of 1 M DTT (dithiothreitol) Assay Method:In a 96 well filter-bottom plate (Millipore, #MSDV N6B 50), 58 μl Assay Buffer is added to reach well. Add 10 μl of Cold ATP mix in Assay Buffer, then 10 μl of a 1:10 dilution of α-Casein stock. Then add 2 μl of compound being tested (DMSO) at a 50× final concentration. Hot ATP mix (10 μl) is added, and the reaction is started with the addition of 10 μl of a 1:350 dilution of the ALK-5 protein (2 nM final) in Assay Buffer with 0.05% BSA (Bovine Serum Albumin). The reaction is mixed for 5 minutes at room temperature, and then continued for 145 minutes at room temperature. The reaction is then stopped with the addition of 100 μl of ice-cold 20% TCA (trichloroacetic acid). The assay is then incubated for at least 1 hour at 4° C., and then the contents of each well are filtered by suction through the filter. The wells are washed three times with 200 μl ice-cold 10% TCA. The plate bottom is blotted before and after removing plastic sub-base, and dried overnight at room temperature. Add 30 μl of scintillation fluid, and count 1 minute per well on a Wallac Tri-Lux scintillation counter.
- Binding Assay The binding of potential ligands to RORγ is measured by competition with [3H]25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA). The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromatography. 15 μg/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 μM to 0.28 nM, for 10 min at rt in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% glycerol (Sigma Cat # G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat # RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer). The competition data of the test compound over a range of concentrations was plotted as percentage inhibition of radioligand specifically bound in the absence of test compound (percent of total signal). After correcting for non-specific binding, IC50 values were determined.
- ALK2 HTRF Assay ALK2 (aa 147-end) was obtained from BPS biosciences. The enzymatic assays were conducted in white 384-well polystyrene plates in a final volume of 8 μL. The inhibitors were serially diluted in DMSO and added to the plate wells prior to addition of the other reaction components. The assays were carried out at 25° C. in the assay buffer (50 mM HEPES, pH 7.0, 10% Glycerol, 0.01% Brij50, 10 mM MgCl2, 1 mM EGTA, 5 mM DTT, and 0.01% BSA), containing 50 nM LANCE Ultra ULight-DNA Topoisomerase 2-alpha peptide (Perkin Elmer TRF0130), and 3 μM ATP. The final concentration of DMSO in the assay was 1% and the enzyme concentration was 0.5 nM for ALK2. The reactions were allowed to proceed for 2 hr for ALK2 after which, the reaction was quenched by addition of EDTA at a final concentration of 20 mM along with 1.5 nM LANCE Ultra Europium-anti-phospho-DNA Topoisomerase 2-alpha (Thr1342) antibody (Perkin Elmer TRF0218). The reaction was incubated at 25° C. for 1 hr and read on a PHERAstar FS plate reader (BMG Labtech). IC50 determination was performed by fitting percent control activity versus the log of the inhibitor concentration using the IDBS XLFit and GraphPad Prism 5.0 software.
- Apoptosis Signal-Regulating Kinase Assay The assay measures the phosphorylation level of a biotinylated peptide substrate by the ASK1 kinase using HTRF detection. This is a competitive, time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay, based on HTRF® KinEASE™-STK manual from Cisbio. Test compound, 1 μM STK3 peptide substrate, 4 nM of ASK1 kinase were incubated with 10 mM MOP buffer, pH. 7.0 containing 10 mM Mg-acetate, 0.025% NP-40, 1 mM DTT, 0.05% BSA and 1.5% glycerol for 30 minutes then 100 μM ATP was added to start the kinase reaction and incubated for 3 hr. Peptide antibody labeled with 1× Eu3+ Cryptate buffer containing 10 mM EDTA and 125 nM Streptavidin XL665 were added to stop the reaction and phosphorylated peptide substrate was detected using Envision 2103 Multilabeled reader from PerkinElmer. The fluorescence was measured at 615 nm (Cryptate) and 665 nm (XL665) and a ratio of 665 nm/615 nm was calculated for each well. The resulting TR-FRET level (a ratio of 665 nm/615 nm) was proportional to the phosphorylation level. Under these assay conditions, the degree of phosphorylation of peptide substrate was linear with time and concentration for the enzyme.
- Binding Assay Compounds were tested in a competition binding assay using 3H-MK591 as tracer. (Preparation of MK-591 is described in Bioorg. Med. Chem. Lett. 1999, 9, 2391). A 100,000×g pellet from COS-7 cells stably transfected with a plasmid expressing human ALOX5AP was the source of FLAP. Membrane pellets were resuspended in buffer (100 mM Tris-HCl, 0.05% Tween-20, 140 mM NaCl, 2 mM EDTA, 0.5 mM DTT, 5% Glycerol, pH 7.5) to give a final protein concentration of 12 mg/mL (2 μg/well). To perform assays, 1.4 μL compounds were dispensed into 96-well plates in 3-fold dilution series in triplicate. 84 μL radioligand (25000 CPM, 2 nM final concentration in assay) was then added followed by 84 μL membrane suspension and incubation at rt for 60 min. Following filtration, filter plates were dried 12 h at RT (or 50° C. for 1 hour). 50 μL scintillant was then added, the filterplates were sealed and radioactivity was measured in a microbeta counter. Specific binding was defined as total binding minus non-specific binding. Total binding was defined as 3H-MK591 bound to membranes in the absence of competitor, non-specific binding was defined as 3H-MK591 in the presence of 0.1 mM MK-591.
- Binding Assay Human eIF4E (aa 28-217) with a C-terminal His tag (HH-eIF4E) was expressed in E. coli in inclusion bodies. The protein was solubilized with 8 M urea and purified under denaturing conditions using nickel-charged HisTrap HP columns (GE Healthcare). The protein was refolded by diluting to approximately 0.25 mg/mL with 6 M urea, 20 mM Hepes pH 7.0, 500 mM NaCl, 1 mM DTT, 1 mM EDTA, and 0.5 M arginine»HCl, and then dialyzing overnight into the same buffer without the urea. The protein was further dialyzed into 20 mM Hepes pH 6.5, 50 mM NaCl, 1 mM EDTA, and 1 mM DTT, filtered, and then concentrated using Hitrap SP sepharose FF columns (GE Healthcare). The protein was dialyzed into 20 mM Hepes pH 7.0, 500 mM NaCl, 5 mM DTT, and 10% glycerol and stored at -80 °C until use. Test compounds (1.6 mM stock in DMSO) were diluted 3 fold in series in DMSO. Compound solutions were diluted 4 fold in Assay Buffer (50 mM sodium phosphate, pH 6.5, 50 mM KC1, 1 mM DTT and 0.5 mg/mL gammaglobulin).
- Bruton's Tyrosine Kinase (BTK) Inhibition Assay The assay is a capture of radioactive 33P phosphorylated product through filtration. The interactions of BTK, biotinylated SH2 peptide substrate (Src homology), and ATP lead to phosphorylation of the peptide substrate. Biotinylated product is bound streptavidin sepharose beads. All bound, radiolabeled products are detected by scintillation counter.Plates assayed are 96-well polypropylene (Greiner) and 96-well 1.2 μm hydrophilic PVDF filter plates (Millipore). Concentrations reported here are final assay concentrations: 10-100 μM compounds in DMSO (Burdick and Jackson), 5-10 nM BTK enzyme (His-tagged, full-length), 30 μM peptide substrate (Biotin-Aca-AAAEEIYGEI-NH2), 100 μM ATP (Sigma), 8 mM imidazole (Sigma, pH 7.2), 8 mM glycerol-2-phosphate (Sigma), 200 μM EGTA (Roche Diagnostics), 1 mM MnCl2 (Sigma), 20 mM MgCl2 (Sigma), 0.1 mg/ml BSA (Sigma), 2 mM DTT (Sigma), 1 μCi 33P ATP (Amersham), 20% streptavidin sepharose beads (Amersham), 50 mM EDTA (Gibco), 2 M NaCl (Gibco), 2 M NaCl w/1% phosphoric acid (Gibco), microscint-20 (Perkin Elmer).
- CYP51 Inhibition Assay Briefly, the reaction mixture contained 1 uM CYP51, 2 uM cytochrome P450 reductase, 100 uM dilauroyl-alpha-phosphatidylcholine, 0.4 mg/ml isoctrate dehydrogenase, and 25mM sodium isocitrate in 20mM MOPS (pH 7.4), 50 mM KCl, 5 mM MgCl2, and 10% glycerol. After the addition of the 3H-radiolabeled sterol substrate (~2000 cpm/nmol, final concentration 50 uM) the mixture was preincubated for 5 min at 37 °C in a shaking water bath (GCA Precision Scientific). The reaction was initiated by the addition of 100 uM NADPH and stopped by extraction of the sterols with ethyl acetate. The reaction products were dried, dissolved in methanol, and analyzed by a reverse-phase HPLC system (Waters) equipped with a beta-RAM detector (INUS Systems, Inc.) using a Nova-Pak C18 column (particle size 4 uM, 3.9 x 150 mm) and a linear gradient consisting of water:acetonitrile:methanol (1.0:4.5:4.5) (solvent A) and methanol (solvent B) at a flow rate of 1 ml/min. Under these conditions the retention time for eburicol, obtusifoliol, and lanosterol was 26, 23, and 25 min, respectively. The retention time for the reaction intermediates, 14alpha-alcohol and 14alpha-aldehyde derivatives of obtusifoliol (30) (as seen in Fig. 3, L. infantum CYP51), was 10 and 12 min, respectively.
- Enzyme Assay For the enzymatic test, human MetAP2 protein was obtained from a culture supernatant of insect cells (sf9) infected with MetAP2 recombinant baculovirus.Before performing the experiment, dialysis of the MetAP2 supernatant was performed over 24 hours at 4° C. in a buffer (10 mM Hepes, 100 mM KCl, 10% glycerol, pH 7.4) in the presence of EDTA (1 mM) over the first 12 hours.The dialysis supernatant was recovered and manganese, used as cofactor, was added to a final concentration of 300 μM.The enzymatic test is a two steps procedure.In a first step, it consists in placing in contact the compound according to the invention, the dialysed MetAP2 protein and the substrate (Met-Pro-Arg-pNa peptide synthesized by Neosystem), the N-terminal methionine of which can be cleaved with MetAP2, and which bears at the C-terminal end a para-nitroaniline (pNa) chromophore, which can itself be released by another peptidase only when the N-terminal methionine has been cleaved beforehand.Consequently, the second step consists in reacting the peptides cleaved in the preceding step with a second peptidase in order to release the chromophore. The peptidase used in this second step is cathepsin, which comes from the TagZyme “DAPase” kit (Quiagen, 34366).The MetAP2 activity is proportional to the amount of para-nitroaniline released, which is measured by absorbance at 405 nm.
- Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1, 1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;
- Enzyme Inhibition Assay Enzyme inhibition was evaluated by measuring NO production with the hemoglobin capture assay, which was performed with purified NOSs in 96-well plates using a Biotek Gen5™ microplate reader. Purified NOSs used in this study, rat nNOS, human nNOS, murine macrophage iNOS, bovine eNOS, and human eNOS, are recombinant enzymes, expressed in E. coli and purified by reported procedures.37-39 For rat and human nNOS, bovine and human eNOS, the assays were performed at 37° C. in 100 mM HEPES buffer with 10% glycerol (pH 7.4) in the presence of 10/M L-arginine and tetrahydrobiopterin, 100 μM NADPH, 0.83 mM CaCl2, 320 units/mL of calmodulin, and 3 μM human oxyhemoglobin. For iNOS, the assay was performed at 37° C. in HEPES buffer in the presence of L-arginine and cofactors (NADPH, H4B, and human oxyhemoglobin). For all the assays, NO production was read by monitoring the absorbance at 401 nm, and kinetic readouts were recorded for 6 min. The inhibition constants (K,) for all NOSs were calculated from the IC50 values and Km (human nNOS: 1.6 M; rat nNOS: 1.3 μM; murine iNOS: 8.2 μM; bovine eNOS: 1.7 μM; human eNOS: 3.9 μM)40 using the Cheng-Prusoff equation: Ki=IC50/(1+[S]/Km).41
- HTRF Assay (1 mM ATP) ALK2 (aa 147-end) was obtained from BPS biosciences. The enzymatic assays were conducted in white 384-well polystyrene plates in a final volume of 8 μL. The inhibitors were serially diluted in DMSO and added to the plate wells prior to addition of the other reaction components. The assays were carried out at 25° C. in the assay buffer (50 mM HEPES, pH 7.1, 10% Glycerol, 0.01% Brij50, 10 mM MgCl2, 1 mM EGTA, 5 mM DTT, and 0.01% BSA), containing 50 nM LANCE Ultra ULight™-DNA Topoisomerase 2-alpha peptide (Perkin Elmer TRF0130), and 1 mM ATP. The final concentration of DMSO in the assay was 1% and the enzyme concentration was 2.5 nM for ALK2. The reactions were allowed to proceed for 2-4 hr after which, the reaction was quenched by addition of EDTA at a final concentration of 20 mM along with 1.5 nM LANCE Ultra Europium-anti-phospho-DNA Topoisomerase 2-alpha (Thr1342) antibody (Perkin Elmer TRF0218). The reaction was read on a PHERAstar FS plate reader (BMG Labtech). IC50 determination was performed by fitting percent control activity versus the log of the inhibitor concentration using the IDBS XLFit and GraphPad Prism 5.0 software.
- HTRF Assay (100 uM ATP) ALK2 (aa 147-end) was obtained from BPS biosciences. The enzymatic assays were conducted in white 384-well polystyrene plates in a final volume of 8 μL. The inhibitors were serially diluted in DMSO and added to the plate wells prior to addition of the other reaction components. The assays were carried out at 25° C. in the assay buffer (50 mM HEPES, pH 7.1, 10% Glycerol, 0.01% Brij50, 10 mM MgCl2, 1 mM EGTA, 5 mM DTT, and 0.01% BSA), containing 50 nM LANCE Ultra ULight™-DNA Topoisomerase 2-alpha peptide (Perkin Elmer TRF0130), and 100 uM ATP. The final concentration of DMSO in the assay was 1% and the enzyme concentration was 2.5 nM for ALK2. The reactions were allowed to proceed for 2-4 hr after which, the reaction was quenched by addition of EDTA at a final concentration of 20 mM along with 1.5 nM LANCE Ultra Europium-anti-phospho-DNA Topoisomerase 2-alpha (Thr1342) antibody (Perkin Elmer TRF0218). The reaction was read on a PHERAstar FS plate reader (BMG Labtech). IC50 determination was performed by fitting percent control activity versus the log of the inhibitor concentration using the IDBS XLFit and GraphPad Prism 5.0 software.
- HTRF Assay (3 uM ATP) ALK2 (aa 147-end) was obtained from BPS biosciences. The enzymatic assays were conducted in white 384-well polystyrene plates in a final volume of 8 μL. The inhibitors were serially diluted in DMSO and added to the plate wells prior to addition of the other reaction components. The assays were carried out at 25° C. in the assay buffer (50 mM HEPES, pH 7.1, 10% Glycerol, 0.01% Brij50, 10 mM MgCl2, 1 mM EGTA, 5 mM DTT, and 0.01% BSA), containing 50 nM LANCE Ultra ULight™-DNA Topoisomerase 2-alpha peptide (Perkin Elmer TRF0130), and 3 uM ATP. The final concentration of DMSO in the assay was 1% and the enzyme concentration was 2.5 nM for ALK2. The reactions were allowed to proceed for 2-4 hr after which, the reaction was quenched by addition of EDTA at a final concentration of 20 mM along with 1.5 nM LANCE Ultra Europium-anti-phospho-DNA Topoisomerase 2-alpha (Thr1342) antibody (Perkin Elmer TRF0218). The reaction was read on a PHERAstar FS plate reader (BMG Labtech). IC50 determination was performed by fitting percent control activity versus the log of the inhibitor concentration using the IDBS XLFit and GraphPad Prism 5.0 software.
- HTRF FRET Assay This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence. Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 μl are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window Inhibitor.
- HTRF FRET Assay This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence. Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window.
- Inhibition Assay 5 uM ATP: Test compounds dissolved and diluted in DMSO (2 μl) were added to a reaction mixture comprising 10 μl of 5× Reaction Buffer (40 mM MOPS pH 7.0, 5 mM EDTA), 10 μl of recombinant human PIM2 solution (4 ng PIM-2 dissolved in dilution buffer (20 mM MOPS pH 7.0; EDTA 1 mM; 5% Glycerol; 0.01% Brij 35; 0.1%; 0.1% 2-mercaptoethanol; 1 mg/ml BSA)) and 8 ul of water. Reactions were initiated by the addition of 10 ul of ATP Solution (49% (15 mM MgCl2; 5 uM ATP) 1% ([γ-33P]ATP: Stock 1 mCi/100 μl; 3000 Ci/mmol (Perkin Elmer)) and 10 ul of substrate peptide solution (RSRSSYPAGT (SEQ ID NO.: 6), dissolved in water at a concentration of 1 mM), Reactions were maintained for 10 min at 30° C. The reactions were quenched with 100 ul of 0.75% Phosphoric acid, then transferred to and filtered through a Phosphocellulose filter plate (Millipore, MSPH-N6B-50). After washing each well 4 times with 0.75% Phosphoric acid, scintillation fluid (20 uL) was added to each well and
- Inhibition Assay Test compounds dissolved and diluted in DMSO (2 μl) were added to a reaction mixture comprising 10 μl of 5× Reaction Buffer (40 mM MOPS pH 7.0, 5 mM EDTA), 10 μl of recombinant human PIM2 solution (4 ng PIM-2 dissolved in dilution buffer (20 mM MOPS pH 7.0; EDTA 1 mM; 5% Glycerol; 0.01% Brij 35; 0.1%; 0.1% 2-mercaptoethanol; 1 mg/ml BSA)) and 8 ul of water. Reactions were initiated by the addition of 10 ul of ATP Solution (49% (15 mM MgCl2; 75 uM ATP) 1% ([γ-33P]ATP: Stock 1 mCi/100 μl; 3000 Ci/mmol (Perkin Elmer)) and 10 ul of substrate peptide solution (RSRSSYPAGT (SEQ ID NO.: 6), dissolved in water at a concentration of 1 mM), Reactions were maintained for 10 min at 30° C. The reactions were quenched with 100 ul of 0.75% Phosphoric acid, then transferred to and filtered through a Phosphocellulose filter plate (Millipore, MSPH-N6B-50). After washing each well 4 times with 0.75% Phosphoric acid, scintillation fluid (20 uL) was added to each well and the resid
- Inhibition Assay The assay is a capture of radioactive 33P phosphorylated product through filtration. The interactions of BTK, biotinylated SH2 peptide substrate (Src homology), and ATP lead to phosphorylation of the peptide substrate. Biotinylated product is bound streptavidin sepharose beads. All bound, radiolabeled products are detected by scintillation counter.Plates assayed are 96-well polypropylene (Greiner) and 96-well 1.2 μm hydrophilic PVDF filter plates (Millipore). Concentrations reported here are final assay concentrations: 10-100 μM compounds in DMSO (Burdick and Jackson), 5-10 nM BTK enzyme (His-tagged, full-length), 30 μM peptide substrate (Biotin-Aca-AAAEEIYGEI-NH2), 100 μM ATP (Sigma), 8 mM imidazole (Sigma, pH 7.2), 8 mM glycerol-2-phosphate (Sigma), 200 μM EGTA (Roche Diagnostics), 1 mM MnCl2 (Sigma), 20 mM MgCl2 (Sigma), 0.1 mg/ml BSA (Sigma), 2 mM DTT (Sigma), 1 μCi 33P ATP (Amersham), 20% streptavidin sepharose beads (Amersham), 50 mM EDTA (Gibco), 2 M NaCl (Gibco), 2 M NaCl w/1% phosphoric acid (Gibco), microscint-20 (Perkin Elmer).
- Inhibition Assay The inhibition of DGAT-1 activity can be assessed in intestinal microsome preparations by monitoring the incorporation of radiolabeled fatty acyl-CoA into DAG.Methods: Commercial microsomal preparations containing 60 ug of protein are incubated in assay buffer [20 uM 1,2-didecanloyl glycerol, 5 uM 14C decanoyl-CoA, 5 mM MgCl2, 0.4% BSA, 0.1% dimethyl sulfoxide (DMSO), 50 mM HEPES-pH 7.5] in the presence of varying concentrations of inhibitors that are dispensed from 100% DMSO stock solutions. Final assay volumes are 200 uL. Reactions are carried out for 45 minutes in 96-well polystyrene microtiter plates at ambient temperature. Following the ambient temperature incubation, assay mixtures are applied to a 96-well filter plate (Catalog # MSHVN4510, Millipore Inc.; Billerica, Mass.) under vacuum. The filter plate is pre-equilibrated with 100 uL of 70% ethanol followed by 200 uL of assay buffer. Filters are dried, removed and placed in scintillation vials with 4 mL of scintillation cocktail (Catalog #6013329; PerkinElmer Inc.; Waltham, Mass.). De novo 14C-TAG formed in the assay and trapped on the filters is quantified with use of a liquid scintillation counter (Model # LS6500 Beckman Coulter, Inc.; Fullerton, Calif.). The IC50 is defined as the concentration of compound that results in a 50% reduction in TAG synthesis.
- Kinase Assay of RIPK1 Materials: Recombinant full-length RIPK1 protein with N-terminal GST-tag (Cat#R07-34G) was purchased from SignalChem. The ADP-Glo kinase assay kit (Cat#V9102) was from Promega. MBP (cat# M2295) protein and all the other chemicals were from Sigma. The 384-well assay plates (Cat#3674, white, opaque) were purchased from Corning. Kinase activity assay and data analysis: The RIPK1 kinase assay was performed in white 384-well plate. The assay buffer contained 25 mM HEPES (pH7.2), 20 mM MgCl2, 12.5 mM MnCl2, 5 mM EGTA, 2 mM EDTA, 12.5 mM β-glycerol phosphate and 2 mM DTT. RIPK1 was first incubated with compounds or DMSO control for 15 mM, then ATP/MBP substrate mixture was added to initiate the reaction. The final concentration of RIPK1 was 161 nM, while the final concentration of ATP was 50 uM, and MBP 20 uM. After 90 min reaction at room temperature, the ADP-Glo reagent and detection solution were added following the technical manual of ADP-Glo kinase assay kit (Promega). The luminescence was measured on PerkinElmer Enspire. The data was analyzed using Graphpad Prism (GraphPad Software; www.graphpad.com). The curves were fitted using a non-linear regression model with a sigmoidal dose response.
- PI3Kδ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kδ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kδ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3K6 assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3K6. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kδ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- PI3K-γ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3K-γ Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kdelta Scintillation Proximity Assay A3 The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- SPA Binding Assay The binding of potential ligands to RORγ is measured by competition with [3H]25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA) binding assay. The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromatography. 15 μg/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 μM to 0.28 nM for 10 min at room temperature in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% Glycerol (Sigma Cat # G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat # RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer). The competition data of the test compound over a range of concentrations was plotted as percentage inhibition of radioligand specifically bound in the absence of test compound (percent of total signal). After correcting for non-specific binding, IC50 values were determined.
- SPA Binding Assay The binding of potential ligands to RORγ is measured by competition with [3H]25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA) binding assay. The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromatography. 15 ug/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 μM to 0.28 nM for 10 min at room temperature in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% Glycerol (Sigma Cat# G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat # RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer). The competition data of the test compound over a range of concentrations was plotted as percentage inhibition of radioligand specifically bound in the absence of test compound (percent of total signal). After correcting for non-specific binding, IC50 values were determined.
- Scintillation Proximity Assay (SPA) To determine the affinity of the compounds of the present invention a SPA is used. The assay is run in a 384-plate format (OptiPlate-384) where each well contains a mix of 5 μL of test compound, 5 μL NR1s1s2 (ligand binding domains of the NMDA receptor, MW 35.6 kDa, 0.075 ug/well final), 5 μL [3H]-MDL-105,519 (radiolabelled, high affinity N-methyl-D-aspartate (NMDA) glutamate receptor antagonist at the glycine site obtained fromSigma Aldrich, final concentration 5 nM, Kd=1.3 nM), 5 μL streptavidin coated imaging beads (Perkin Elmer cat. No.: RPNQ0273, 8 ug/well). The assay buffer contains 100 mM HEPES-NaOH, 150 mM NaCl, 1 mM EDTA, 10% glycerol at pH 7.4 in ultra-pure water. Non-specific binding is defined by inclusion of 10 μM L-689,560 (highly potent NMDA antagonist) and total binding by 1% DMSO. Following 30 minutes incubation in the dark (shaker, Multi-microplate Genie), the SPA beads are allowed to settle for 3 h after which the signal is read on a Viewlux instrument (Perkin Elmer). Normalized data are used to calculate IC50 and Ki values.
- Scintillation Proximity Assay Assay A3: The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P]ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- Scintillation Proximity Assay The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 M PIP2, 20 M ATP, 0.2 μCi [γ-33P]ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 M ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- ATR/ATRIP Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 hours with 1 mL of anti-FLAG resin (Sigma catalog # A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 m/ml 3×FLAG peptide).The ability of new chemical matter to inhibit the ATR catalytic activity in this ATR/ATRIP complex was assessed using a Caliper-based assay. A 2× enzyme solution (i.e., 4 nM enzyme) was prepared using 1× Kinase Reaction Buffer (25 mM HEPES pH 8, 0.0055% Brij-35, 10 mM MnCl2, and 1 mM DTT). A 2× peptide solution was then prepared consisting of 10 uM FAM-labeled RAD17 peptide (GL Biochem, catalog #524315) in 1× Kinase Reaction Buffer supplemented with 2 μM ATP. 10 μL of the 2× enzyme solution was transferred to an assay plate containing 60 nL of test compound (from a 3× serial dilution) in 100% DMSO. Following a 30 minute incubation at 28° C., 10 μL of the 2× peptide solution was then transferred to the same assay plate. The reaction was allowed to incubate at 28° C. for 6 hours. After adding 30 μL of stop buffer (100 mM HEPES pH 7.5, 0.015% Brij-35, 0.2% Coating-3 Reagent (PerkinElmer, catalog # PN760050), and 50 mM EDTA), data were collected on a Caliper instrument. Conversion values were converted to inhibition values via the following equation: % inhibition=(max−conversion)/(max−min)*100, whereby “max” corresponds to the DMSO control and “min” corresponds to the low control. IC50 values were calculated using the following equation in XLFit: Y=Bottom+(Top-Bottom)/1+(IC50/X){circumflex over ( )}HillSlope).
- ATR/ATRIP Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 h with 1 mL anti-FLAG resin (Sigma catalog #A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 μg/ml 3×FLAG peptide).The ability of new chemical matter to inhibit the ATR catalytic activity in this ATR/ATRIP complex was assessed using a Caliper-based assay. A 2× enzyme solution (i.e., 4 nM enzyme) was prepared using 1× Kinase Reaction Buffer (25 mM HEPES pH 8, 0.0055% Brij-35, 10 mM MnCl2, and 1 mM DTT). A 2× peptide solution was then prepared consisting of 10 uM FAM-labeled RAD17 peptide (GL Biochem, catalog #524315) in 1× Kinase Reaction Buffer supplemented with 2 μM ATP. 10 μL of the 2× enzyme solution was transferred to an assay plate containing 60 nL of test compound (from a 3× serial dilution) in 100% DMSO. Following a 30-min incubation at 28° C., 10 μL of the 2× peptide solution was then transferred to the same assay plate. The reaction incubated at 28° C. for 6 h. After adding 30 μL stop buffer (100 mM HEPES pH 7.5, 0.015% Brij-35, 0.2% Coating-3 Reagent (PerkinElmer, catalog #PN760050), and 50 mM EDTA), data were collected on a Caliper instrument. Conversion values were converted to inhibition values via the following equation: % inhibition=(max−conversion)/(max−min)*100, wherein “max” corresponds to the DMSO control, and “min” corresponds to the low control. IC50 values were calculated using the following equation in XLFit: Y=Bottom+(Top−Bottom)/1+(IC50/X){circumflex over ( )}HillSlope).
- ATR/ATRIP Enzymatic Assay Human full-length FLAG-TEV-ATR and His6-ATRIP were co-expressed in HEK293 cells. The cell pellet (20 g) was harvested and lysed in 100 mL of lysis buffer (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 1% (v/v) Tween-20, 0.1% (v/v) NP-40, complete protease inhibitor cocktail tablets, phosphatase inhibitor cocktail tablets, 2 mM MgCl2, 0.2 mM EDTA, and 1 mM ATP). After sonication and centrifugation, the supernatant was incubated at 4° C. for 3 hours with 1 mL of anti-FLAG resin (Sigma catalog # A2220) that had been pre-equilibrated in buffer A (20 mM Tris-HCl pH 7.5 at room temperature, 137 mM NaCl, 10% glycerol, 1 mM DTT, 2 mM MgCl2, and 0.2 mM EDTA). The sample was loaded into a column, and then washed with buffer A three times. Protein was subsequently eluted with 2 ml of buffer B (buffer A+200 μg/ml 3×FLAG peptide).The ability of new chemical matter to inhibit the ATR catalytic activity in this ATR/ATRIP complex was assessed using a Caliper-based assay. A 2× enzyme solution (i.e., 4 nM enzyme) was prepared using 1× Kinase Reaction Buffer (25 mM HEPES pH 8, 0.0055% Brij-35, 10 mM MnCl2, and 1 mM DTT). A 2× peptide solution was then prepared consisting of 10 uM FAM-labeled RAD17 peptide (GL Biochem, catalog #524315) in 1× Kinase Reaction Buffer supplemented with 2 μM ATP. 10 μL of the 2× enzyme solution was transferred to an assay plate containing 60 nL of test compound (from a 3× serial dilution) in 100% DMSO. Following a 30 minute incubation at 28° C., 10 μL of the 2× peptide solution was then transferred to the same assay plate. The reaction was allowed to incubate at 28° C. for 6 hours. After adding μL of stop buffer (100 mM HEPES pH 7.5, 0.015% Brij-35, 0.2% Coating-3 Reagent (PerkinElmer, catalog # PN760050), and 50 mM EDTA), data were collected on a Caliper instrument. Conversion values were converted to inhibition values via the following equation: % inhibition=(max−conversion)/(max−min)*100, whereby “max” corresponds to the DMSO control and “min” corresponds to the low control. IC50 values were calculated using the following equation in XLFit: Y=Bottom+(Top−Bottom)/1+(IC50/X){circumflex over ( )}HillSlope).
- HCMV Polymerase LANCE TR-FRET Assay The assay conditions are the following: 10 mM HEPES pH 7.5, 25 mM KCl, 7.5 mM NaCl, 5 mM MgCl2, 0.2 mg BSA/mL, 1 mM TCEP, 1.5% glycerol, 5% DMSO, 235 nM dATP, 350 nM dCTP, 350 nM dGTP, 235 nM dTTP, 12 nM biotin-16-dUTP, 23.5 nM Dig-primer/template, 2 nM GST-UL54. The assay volume is 10 μL. Each reagent is added as follow: 4 μL a+3 μL b+3 μL c; a: compound diluted in compound dilution buffer to obtain 12.5% DMSO; b: enzyme (GST-UL54) in 10 mM Hepes pH 7.5, 25 mM KCl, 5 mM MgCl2, 25 mM NaCl, 5% Glycerol, 0.67 mg BSA/mL, 1 mM TCEP w/o DMSO (2 nM GST-UL54 is present in the assay); c: substrate in 10 mM HEPES pH 7.5, 25 mM KCl, 5 mM MgCl2, 1 mM TCEP, 783 nM dATP, 1166 nM dCTP, 1166 nM dGTP, 783 nM dTTP, 40 nM biotin-16-dUTP, 78 nM Dig-primer (5'-/Dig/AGC TCG TTT AGT GAA CC-3')/template (5'-GAG GTC AAA ACA GCG TGG ATG GCG TCT CCA GGC GAT CTG ACG GTT CAC TAA ACG AGC T-3') w/o DMSO. The primer and template are annealed in 10 mM Tris-HCl pH 7.5, 50 mM NaCl at a respective concentration of 50 μM. They are incubated at 95 °C. for 5 min in a dry batch block. The block is removed from the dry bath and allowed to cool to RT. Aliquots are made and stored at −20 °C. To perform the assay, 3 μL of the enzyme solution is added to columns 2-12 and 14-24. The enzyme is substituted by the blank solution (b solution without enzyme) for columns 1 and 13 (blanks). The plate is centrifuged at 200×g for 30 sec. 3 μL of substrate solution is added to each well. The plate is centrifuged at 200×g for 30 sec. Plates are incubated at 37 °C. for 30 min. 5 μL of conjugate solution is added (25 mM Hepes pH 7.5, 0.1 M NaCl, 0.25% Tween-20, 1 mg/mL BSA, 12 mM EDTA, 24 nM Sreptavidin-APC, 342 ng/mL Anti-Dig-Europium). The plates are incubated at RT for at least 120 min. The signal is read on the Envision plate reader (Perkin-Elmer) or equivalent.
- BCA Protein Assay Escherichia coli BL21*DE3 pET30a-Ec yeaWX #1 (Ec YeaWX) strain was generated as described below. The contiguous Escherichia coli coding sequence yeaW (equivalent to uniprot ID P0ABR7.1 (YeaW) (SEQ ID NO: 2)) and yeaX (equivalent to uniprot ID P76254.1 (YeaX) (SEQ ID NO: 3)) were PCR amplified from Escherichia coli strain K-12 substr. BW25113 genomic DNA. PCR primers (YeaW_Nde I_fwd2-SEQ ID NO: 4; YeaX_rev2-SEQ ID NO: 5) were designed to create a 5′ NdeI restriction site including the ATG start codon of yeaW and create a PstI restriction site just 3′ of the yeaX TAG stop codon.The bacteria were grown aerobically in 50 mL LB broth (Difco #244620; 10 g/L Tryptone, 5 g/L yeast extract, 10 g/L NaCl, 50 μg/mL kanamycin), in a 500 mL Erlenmeyer flask. The cultures were inoculated from glycerol stock of BL21*DE3 pET30a-Ec yeaWX #1 strain. Strains were cultured all day at 37° C. with 250 rpm shaking. Two 300 mL Minimal M9 Medium (6 g/L Na2HPO4, 3 g/L KH2PO4, 0.5 g/L NaCl, 1 g/L NH4Cl, 0.1 mM CaCl2, 1 mM MgSO4, 0.2% Dextrose, 1 mg/L Thiamine, 50 μg/mL kanamycin), in 1 L Erlenmeyer flasks, were inoculated with 5 mL of the LB broth day culture and cultured overnight at 37° C. with 250 rpm shaking. The overnight cultures were used to inoculate twelve 1 L cultures of Minimal M9 media in 2.8 L fluted Erlenmeyer flasks to an OD 600 nm of 0.05 (typically approximately 28 mLs), which were grown at 37° C. with 250 rpm shaking until an OD600 of approximately 0.4 was reached. Expression of YeaWX was induced with 1 mM IPTG and the induced cultures were further grown overnight at 37° C. with 250 rpm shaking. The biomass was pelleted by centrifugation at 6000×g for 12 minutes at 4° C. The cell pellet was suspended in 240 mL of ice-cold 1× Phosphate Buffered Saline (Ca2+ and Mg2+ free). Ninety micrograms of Lysozyme (Sigma #L6876 Lot #SLBG8654V; Sigma-Aldrich Corp., St. Louis, Mo.) was added and incubated with 320 rpm shaking for 30 minutes at 4° C. Lysis was achieved via French press with a 4° C. prechilled 1″ diameter chamber at 1000 psi (high ratio; internal PSI equivalent ˜16000). The lysate was centrifuged at 6,000×g for 12 minutes at 4° C. to pellet extra debris. Glycerol was added to the centrifuged lysate supernatant at a final concentration of 15% A protein concentration of the centrifuged lysate supernatant was determined by a BCA Protein Assay Kit (Pierce #23225), typically in the 2.5 to 4.5 mg/ml range. The centrifuged Ec YeaWX lysate supernatant was aliquoted into 20 mL volumes and stored frozen at −80° C.Ec YeaWX lysate was diluted to 2.0 mg/mL protein with 1× Dulbecco's phosphate buffered saline (DPBS) plus 15% glycerol. Nicotinamide adenine dinucleotide phosphate (NADPH) was added to 250 μM. One hundred and fifty microliters of Ec YeaWX lysate was dispensed into a deep-well plate (polypropylene, 2 mL volume, Corning Axygen catalogue #P-DW-20-C). Candidate IC50 compounds from TABLE 1 and vehicle control (respective vehicle control of DMSO or water), or control compounds (IC50 control, 8-Quinolinol hemisulfate salt (Sigma Catalog #55100)) were added at a 1:100 dilution (e.g., 1.5 μL per well). The plates were agitated on a plate shaker for 1 minute. d9-carnitine chloride (1.5 μL of 5 mM) was added to all wells to reach a final d9-carnitine chloride concentration of 50 μM.
- Binding Assay Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. #NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. #RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader.
- Chelation-Enhanced Fluorescence (CHEF) Assay CDK4/Cyclin D1 and CDK6/Cylcin D3: The Chelation-Enhanced Fluorescence (CHEF) monitors the phosphorylation state in real time where the level of fluorescence is directly proportional to the amount of phosphorylated substrate. CHEF exploits a synthetic α-amino acid with a side chain bearing an 8-hydroxyquinoline derivative (sulfonamido-oxine, Sox) which, upon coordination to Mg(II), relays information on the phosphorylation state of a proximal serine, threonine or tyrosine residue in peptide-based kinase substrates. Phosphorylation of a specific peptide (Catalog # AQT0258) from AssayQuant Technologies results in an increase in fluorescence at the excitation and emission wavelengths of 360 nm Ex/485 nm Em.Examples along with DMSO (negative) and Palbociclib (positive) controls were added to 384-well plates at 100-fold their final concentrations followed by the addition of 10 nM CDK4/Cyclin D1 (LJIC-2007F1) or 10 nM CDK6/Cyclin D3 (LJIC-2009H2) for a 20 minute pre-incubation in assay buffer containing 40 mM HEPES, 1 mM Dithiothreito (DTT, 10 mM MgCl2, 1% Glycerol, 0.1% BSA. Enzyme reactions were initiated by the addition of AssayQuant Technologies peptide and ATP substrates (10 μM CHEF peptide (Catalog # AQT0258), 2 mM ATP) and allowed to proceed for 2 hours followed by fluorescence read of the reaction. Ki determinations were made from a plot of the fractional velocity as a function of inhibitor concentration fit to the Morrison equation with the enzyme concentration as a variable.
- Competition Binding Assay Run the competition binding assay in a buffer containing 50 mM HEPES, pH 7.5, 1.5 mM EDTA, 150 mM NaCl, 10% glycerol, 1 mg/mL ovalbumin, and 5 mM DTT, using 0.025 μCi per well 3H-estradiol (118 Ci/mmol, 1 mCi/mL), 7.2 ng/well ERα (wild type), or 7.2 ng/well ERα (Y537S mutant) or 7.7 ng/well ERβ receptor. Add the test compound at 10 different concentrations ranging from 10,000 nM to 0.5 nM, and determine nonspecific binding in the presence of 1 μM of 1713 estradiol. Incubate the binding reaction (140 μL) for 4 hours at room temperature, and then add cold dextran-charcoal buffer (70 μL) (containing per 50 mL of assay buffer, 0.75 g of charcoal and 0.25 g of dextran) to each reaction. Mix the plates for 8 minutes on an orbital shaker at 4° C. and then centrifuge at 3000 rpm at 4° C. for 10 minutes. Transfer an aliquot (120 μL) of the mixture to another 96-well, white flat bottom plate (Costar) and add Perkin Elmer Optiphase Supermix scintillation fluid (175 μL) to each well. Seal the plates and shake vigorously on an orbital shaker. After an incubation of 2.5 hours, read the plates in a Wallac Microbeta counter.
- EN PA FRET Inhibition Assay EN PA FRET inhibition assay was performed using a 19 nucleotide synthetic oligoribonucleotide substrate: 5′-FAM-AUUUUGUUUUUAAUAUUUC-BHQ-3′ (Integrated DNA Technologies, Inc., Coralville, Iowa) (SEQ. ID. NO. 1). Upon RNA cleavage, the fluorescent FAM group is released from the BHQ quencher. The PA sequence used to produce active enzyme is derived from any one of multiple influenza A virus strains (e.g., A/goose/Nanchang/3-120/01 (H3N2), A/Victoria/3/1975 (H3N2), A/Brisbane/10/2007 (H3N2), A/WSN/33 (H1N1), A/CA/4/2009 (H1N1), A/CA/5/2009 (H1N1), A/Shanghai/1/2013 (H7N9), A/Guizhou/1/2009 (H5N1)). The full length recombinant protein was expressed from a baculovirus vector in insect cells. Full length EN PA was used in this assay at an effective concentration of 1 to 10 nM, together with 50 nM FRET probe with a final volume of 20 ml cleavage buffer (20 mM Tris Ph8, 100 mM NaCl, 5% Glycerol, 10 mM 3-ME, 0.0003% Tween-20, 5 mM MgC2).Compounds described herein were added to a 384-well black polypropylene plate. Fluorescence was measured in a continuous mode up to 120 minutes with a Wallac 1420 Victor3V multilabel counter (PerkinElmer Life Sciences, Shelton, Conn.) (excitation 485 nm; emission 535 nm).
- Enzyme Assay Data on TC-PTP The assay was carried out at room temperature in 96 well plates. The reaction mixture in 170 μl contained 50 mM Bis-Tris (pH=6.3), 2 mM EDTA, 5 mM N,N′-dimethyl-N,N′bis(mercaptoacetyl)hydrazine (DMH) and 10 μM fluorescein diphosphare (FDP) or 6,8-difluoro-4-methylumbelliferyl phosphate (DiFMUP). 10 μl of 10 concentrations (serial dilution) of the test compound (inhibitor) dissolved in DMSO or DMSO alone for control was added to each well and the plate was mixed for 2 min. The reaction was initiated by adding 20 μl of diluted TC-PTP (50 nM for FDP, 0.5 nM for DiFMUP in 50 mM Bis/Tris (pH=6.3), 2 mM EDTA, 5 mM DMH, 20% glycerol and 0.01% Triton X-100. The phosphatase activity was followed by monitoring the appearance of the fluorescent product fluorescein monophosphate (FMP) or 6,8-difluoro-7-hydroxyl-4-coumarin (DiFMU) continuously for 15-30 min, using the Spectromax Gemini fluorescent plate reader (Molecular probes) with excitation of 440 nm and emission at 530 nm (cutoff filter at 525 nm) for FDP and excitation at 360 nm and emission at 450 nm (cutoff filter at 435 nm) for DiFMUP. All the assays were done at least in duplicate. The initial rate of FMP or DiFMU formation is plotted against the concentration of inhibitor and the data was fitted to 4-parameter equation and the inflection point of the fit is the IC50.
- Enzyme Assay HIS-tagged IDO1 protein was recombinantly expressed in Escherichia coli using ZYP5052 autoinduction media supplemented with 500 μM delta aminolevulinic acid for 48 h at 16° C. IDO1 protein was purified using Ni2+-affinity resin and size exclusion chromatography. Purified protein was then diluted in assay buffer (50 mM Tris pH 7.0, 1% glycerol, 20 μM methylene blue, 0.05% Tween-20, 20 mM sodium ascorbate, 100 units/mL catalase to obtain a final IDO1 concentration of 40 nM. IDO1 solution (30 μM) or buffer alone (30 μM) were dispensed to wells of the assay plate using a BioRAPTR liquid dispenser (Beckman Coulter). Assay plates containing compound and IDO1 enzyme were incubated at RT for 30 min. Afterwards, 10 μL of 400 μM tryptophan in assay buffer were added to each well of the assay plate using a BioRAPTR liquid dispenser. Plates were incubated at RT for 60 min and reactions were quenched by addition of 10 μL of 0.5 M methyl isonipecotate in dimethyl sulfoxide. Plates were sealed and incubated at 37° C. for 4 h or 50° C. for 2 h. The plates are allowed to cool and then centrifuged for 1 min at 1000×g. The resulting fluoresence was measured in an Envision plate reader (Perkin Elmer) with a 400/25 nm excitation filter and an 510/20 nm emission filter.
- Enzyme Assay HIS-tagged IDO1 protein was recombinantly expressed in Escherichia coli using ZYP5052 autoinduction media supplemented with 500 μM delta aminolevulinic acid for 48 hours at 16 degrees Celsius. IDO1 protein was purified using Ni2+-affinity resin and size exclusion chromatography. Purified protein was then diluted in assay buffer (50 mM Tris pH 7.0, 1% glycerol, 20 μM methylene blue, 0.05% Tween-20, 20 mM sodium ascorbate, 100 units/mL catalase to obtain a final IDO1 concentration of 40 nM. IDO1 solution (30 μM) or buffer alone (30 μM) was dispensed to wells of the assay plate using a BioRAPTR liquid dispenser (Beckman Coulter). Assay plates containing compound and IDO1 enzyme were incubated at room temperature for 30 minutes. Afterwards, 10 μL of 400 μM tryptophan in assay buffer were added to each well of the assay plate using a BioRAPTR liquid dispenser. Plates were incubated at room temperature for 60 minutes and reactions were quenched by addition of 10 μL of 0.5 M methyl isonipecotate in dimethyl sulfoxide. Plates were sealed and incubated at 37 degrees Celsius for 4 hours or 50 degrees Celsius for 2 hours. The plates are allowed to cool and then centrifuged for 1 minute at 1000×g. The resulting fluorescence was measured in an Envision plate reader (Perkin Elmer) with a 400/25 nm excitation filter and an 510/20 nm emission filter.
- Enzyme Assay HIS-tagged IDO1 protein was recombinantly expressed in Escherichia coli using ZYP5052 autoinduction media supplemented with 500 μM delta aminolevulinic acid for 48 hours at 16 degrees Celsius. IDO1 protein was purified using Ni2+-affinity resin and size exclusion chromatography. Purified protein was then diluted in assay buffer (50 mM Tris pH 7.0, 1% glycerol, 20 μM methylene blue, 0.05% Tween-20, 20 mM sodium ascorbate, 100 units/mL catalase to obtain a final IDO1 concentration of 40 nM. IDO1 solution (30 μM) or buffer alone (30 μM) were dispensed to wells of the assay plate using a BioRAPTR liquid dispenser (Beckman Coulter). Assay plates containing compound and IDO1 enzyme were incubated at room temperature for 30 minutes. Afterwards, 10 μL of 400 μM tryptophan in assay buffer were added to each well of the assay plate using a BioRAPTR liquid dispenser. Plates were incubated at room temperature for 60 minutes and reactions were quenched by addition of 10 μL of 0.5 M methyl isonipecotate in dimethyl sulfoxide. Plates were sealed and incubated at 37° C. for 4 hours or 50° C. for 2 h. The plates are allowed to cool and then centrifuged for 1 minute at 1000×g. The resulting fluoresence was measured in an Envision plate reader (Perkin Elmer) with a 400/25 nm excitation filter and an 510/20 nm emission filter.
- Enzyme Assay HIS-tagged IDO1 protein was recombinantly expressed in Escherichia coli using ZYP5052 autoinduction media supplemented with 500 uM delta aminolevulinic acid for 48 h at 16° C. IDO1 protein was purified using Ni2+-affinity resin and size exclusion chromatography. Purified protein was then diluted in assay buffer (50 mM Tris pH 7.0, 1% glycerol, 20 uM methylene blue, 0.05% Tween-20, 20 mM sodium ascorbate, 100 units/mL catalase to obtain a final IDO1 concentration of 40 nM. IDO1 solution (30 uM) or buffer alone (30 uM) were dispensed to wells of the assay plate using a BioRAPTR liquid dispenser (Beckman Coulter). Assay plates containing compound and IDO1 enzyme were incubated at RT for 30 min. Afterwards, 10 uL of 400 uM tryptophan in assay buffer were added to each well of the assay plate using a BioRAPTR liquid dispenser. Plates were incubated at RT for 60 min and reactions were quenched by addition of 10 uL of 0.5 M methyl isonipecotate in dimethyl sulfoxide. Plates were sealed and incubated at 37° C. for 4 h or 50° C. for 2 h. The plates are allowed to cool and then centrifuged for 1 min at 1000 ug. The resulting fluorescence was measured in an Envision plate reader (Perkin Elmer) with a 400/25 nm excitation filter and an 510/20 nm emission filter.
- Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1, 1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.
- Enzyme Inhibition Assay Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C.
- Enzyme Inhibition Assay Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row 0. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C.
- Enzyme Inhibition Assay Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C.
- Fluorescence MPro inhibition assay Compounds were seeded into assay-ready plates (Greiner 384 low volume, cat 784900) using an Echo 555 acoustic dispenser, and DMSO was back-filled for a uniform concentration in assay plates (DMSO concentration maximum 1%) Screening assays were performed in duplicate at 20uM and 50uM. Hits of greater than 50% inhibition at 50uM were confirmed by dose response assays. Dose response assays were performed in 12 point dilutions of 2-fold, typically beginning at 100uM. Highly active compounds were repeated in a similar fashion at lower concentrations beginning at 10uM or 1uM. Reagents for Mpro assay were dispensed into the assay plate in 10ul volumes for a final volume of 20uL. Final reaction concentrations were 20mM HEPES pH7.3, 1.0mM TCEP, 50mM NaCl, 0.01% Tween-20, 10% glycerol, 5nM Mpro, 375nM fluorogenic peptide substrate ([5-FAM]-AVLQSGFR-[Lys(Dabcyl)]-K-amide). Mpro was pre-incubated for 15 minutes at room temperature with compound before addition of substrate and a further 30 minute incubation. Protease reaction was measured in a BMG Pherastar FS with a 480/520 ex/em filter set. Raw data was mapped and normalized to high (Protease with DMSO) and low (No Protease) controls using Genedata Screener software. Normalized data was then uploaded to CDD Vault (Collaborative Drug Discovery). Dose response curves were generated for IC50 using nonlinear regression with the Levenberg–Marquardt algorithm with minimum inhibition = 0% and maximum inhibition = 100%.
- Fluorogenic Inhibition Assay Boc-Lys(Ac)-7-amino-4-methylcoumarin (Boc-Lys(Ac)-AMC) was used as substrate for the HDAC assays. Substrate solution was prepared as follow: Boc(Lys-Ac)-AMC was dissolved in DMSO and diluted with HDAC buffer (15 mM Tris-HCl [pH 8.1], 250 μM EDTA, 250 mM NaCl, 10% glycerol) to give 1 mM solutions containing 1.7% DMSO. Trypsin was used to stop the reaction, releasing free AMC. The trypsin solution was prepared as follow: trypsin was dissolved in HDAC buffer to give a concentration of 10 mg/mL. Release of AMC was monitored by measuring the fluorescence at 460 nm (lex=390 nm) with a microplate reader (SpectraMax Gemini) at 37° C. The AMC signals were recorded against a blank with buffer, substrate and trypsin but without the enzyme. All experiments were carried out at least in triplicate. For HDAC inhibition assays, inhibitor diluted in 50 μL of HDAC buffer was mixed with 10 μL of diluted enzyme solution in HDAC buffer at room temperature. The HDAC reaction was started by adding 40 μL of substrate solution in HDAC buffer followed by 30 min of incubation with stirring at 37° C. The reaction was stopped by adding 100 μL, of trypsin solution. After a 10 min incubation with stirring at 37° C., the release of AMC was monitored by measuring the fluorescence.
- General RORgamma SPA binding assay The binding of potential ligands to RORγ is measured by competition with [3H]25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA). The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromatography. 15 μg/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 μM to 0.28 nM, for 10 min at rt in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% glycerol (Sigma Cat#G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat # RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer). The competition data of the test compound over a range of concentrations was plotted as percentage inhibition of radioligand specifically bound in the absence of test compound (percent of total signal). After correcting for non-specific binding, IC50 values were determined. The IC50 value is defined as the concentration of test compound needed to reduce [3H] 25-hydroxycholesterol specific binding by 50% and is calculated using the four parameter logistic equation to fit the normalized data.
- HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window.
- Inhibition of IDH1 R132H in a Biochemical Assay IDH1 R132H catalyzes the NADPH-dependent reduction of alpha-ketoglutarate (α-KG) to (2R)-2-hydroxyglutarate (2-HG). NADPH consumption is determined by luminescence.The biochemical reactions were carried out at 32° C. in a 384-well titre plate in a reaction volume of 41 μL in each case and under the following buffer conditions: 50 mM Tris pH 7.5, 100 mM NaCl, 20 mM MgCl2, 0.05% BSA, 0.01% Brij, 1 μM NADPH, and 250 μM α-KG. The IDH1 R132H enzyme was used at a final concentration of 1.5 nM. Test compounds were assayed in a concentration range of 0.002 to 10 μM. The final DMSO concentration was 2.4%.The reaction was incubated for 30 minutes, after which 40 μL of a detection mixture (0.75 μg/ml luciferase, 0.02 U/ml oxidoreductase, 4 μg/mL FMN, 2 μL/ml decanal/ethanol, 50 mM Tris pH 7.5, 0.5% glycerol, 0.01% Tween 20, 0.05% BSA) were added. The luminescence was determined using a luminescence reader (10 seconds measurement time, 1 second integration period, 30% sensitivity). The drop in luminescence is proportional to the activity of mlDH1. IC50 values were determined by interpolation from plots of the relative luminescence against the inhibitor concentration.
- Kinase Assay FLT3: Inhibition of FLT3 kinase activity by a test compound disclosed herein was estimated by radiometric assay. Standard assay conditions were 5 ng of recombinant FLT3 (Thermo Fisher) with 2 μg of substrate Poly-(Glu 4:Tyr 1) (sigma) in the assay buffer in kinase reaction buffer (10 mM MOPS pH 7.0, 0.21 mM EDTA, 0.5% glycerol, 0.001% Brij-35, 0.01 2-mercaptoehtanol, 1 mg/ml BSA, MgCl2 10 mM, 10 μM ATP, 0.1 μCi per well [33P]-ATP, in the presence of test compound (diluted in final concentration of 4% DMSO) or DMSO control, with a final volume of 25 μl for 60 minutes at 30° C. The reaction was stopped by adding 5 μl of 3% phosphoric acid solution. Total reaction solution was then harvested onto a filter plate (UniFilter-96 GF/B, PerkinElmer), and washed 20 times for 5 min with dH2O. 30 μl of MicroScint™-20 Cocktail (PerkinElmer) was added to dried plate. The plate was sealed and counted using a TopCount scintillation detector (PerkinElmer). The readout from control reaction (complete reaction mixture) was designated as 0% inhibition and the readout for the reaction without enzyme as 100% inhibition. The IC50 values of quinoxaline compounds of this invention against FLT3 kinase were determined using the GraphPad Prism 5 software.
- Kinase Assay PDGFRβ: Inhibition of PDGFRβ kinase activity by a test compound disclosed herein was estimated by radiometric assay. Standard assay conditions were 10 ng of recombinant PDGFRβ (SignalChem) with 2 μg of substrate Poly-(Glu 4:Tyr 1) (sigma) in the assay buffer in kinase reaction buffer (10 mM MOPS pH 7.0, 0.21 mM EDTA, 0.5% glycerol, 0.001% Brij-35, 0.01 2-mercaptoehtanol, 1 mg/ml BSA, 10 mM MgCl2, 10 mM MnCl2, 10 μM ATP, 0.1 μCi per well [33P]-ATP), in the presence of test compound (diluted in final concentration of 4% DMSO) or DMSO control, with a final volume of 25 μl for 60 minutes at 30° C. The reaction was stopped by adding 5 μl of 3% phosphoric acid solution. Total reaction solution was then harvested onto a filter plate (UniFilter-96 GF/B, PerkinElmer), and washed 20 times for 5 min with dH2O. 30 μl of MicroScint™-20 Cocktail (PerkinElmer) was added to dried plate. The plate was sealed and counted using a TopCount scintillation detector (PerkinElmer). The readout from control reaction (complete reaction mixture) was designated as 0% inhibition and the readout for the reaction without enzyme as 100% inhibition. The IC50 values of quinoxaline compounds of this invention against PDGFRβ kinase were determined using the GraphPad Prism 5 software.
- Kinase Assay c-KIT: Inhibition of c-KIT kinase activity by a test compound disclosed herein was estimated by radiometric assay. Standard assay conditions were 20 ng of recombinant c-Kit (SignalChem) with 2 μg of substrate Poly-(Glu 4:Tyr 1) (sigma) in the assay buffer in kinase reaction buffer (10 mM MOPS pH 7.0, 0.21 mM EDTA, 0.5% glycerol, 0.001% Brij-35, 0.01 2-mercaptoehtanol, 1 mg/ml BSA, 10 mM MgCl2, 10 mM MnCl2, 10 μM ATP, 0.1 μCi per well [33P]-ATP, in the presence of test compound (diluted in final concentration of 4% DMSO) or DMSO control, with a final volume of 25 μl for 60 minutes at 30° C. The reaction was stopped by adding 5 μl of 3% phosphoric acid solution. Total reaction solution was then harvested onto a filter plate (UniFilter-96 GF/B, PerkinElmer), and washed 20 times for 5 min with dH2O. 30 μl of MicroScint™-20 Cocktail (PerkinElmer) was added to dried plate. The plate was sealed and counted using a TopCount scintillation detector (PerkinElmer). The readout from control reaction (complete reaction mixture) was designated as 0% inhibition and the readout for the reaction without enzyme as 100% inhibition. The IC50 values of quinoxaline compounds of this invention against c-KIT kinase were determined using the GraphPad Prism 5 software.
- Mobility Shift Assay The purpose of the CDK6/Cyclin D3 assay is to evaluate the inhibition (% inhibition, Kiapp and Ki values) in the presence of small molecule inhibitors by using a fluorescence based microfluidic mobility shift assay. CDK6/Cyclin D3 catalyzes the production of ADP from ATP that accompanies the phosphoryl transfer to the substrate peptide 5-FAM-Dyrktide (5-FAM-RRRFRPASPLRGPPK) (SEQ ID NO:1). The mobility shift assay electrophoretically separates the fluorescently labeled peptides (substrate and phosphorylated product) following the kinase reaction. Both substrate and product are measured and the ratio of these values is used to generate % conversion of substrate to product by the LabChip EZ Reader. Typical reaction solutions contained 2% DMSO (±inhibitor), 2% glycerol, 10 mM MgCl2, 1 mM DTT, 3.5 mM ATP, 0.005% Tween 20 (TW-20), 3 μM 5-FAM-Dyrktide, 4 nM (active sites) activated CDK6/Cyclin D3 in 40 mM HEPES buffer at pH 7.5.Inhibitor Ki determinations for activated CDK6/Cyclin D3 (LJIC-2009G1/2010+PO4) were initiated with the addition of ATP (50 μL final reaction volume), following a eighteen minute pre-incubation of enzyme and inhibitor at 22° C. in the reaction mix. The reaction was stopped after 95 minutes by the addition of 50 μL of 30 mM EDTA. Ki determinations were made from a plot of the fractional velocity as a function of inhibitor concentration fit to the Morrison equation with the enzyme concentration as a variable.
- Processive DNA synthesis assay Processive DNA synthesis was assessed by two types of assays: the Rapid Plate Assay and the M13 assay. The Rapid Plate Assay was performed as previously described. Briefly, a 5′-biotinylated 100-nucleotide template that contains adenines only at its 5′ distal end was annealed with a 15-nucleotide primer to its 3′ end and attached to streptavidin-coated 96-plate wells (Roche Applied Science). DNA synthesis was carried out in 50 μL reaction mixture containing 100 mM (NH)2S04, 20 mM Tris-HCl (pH 7.5), 3 mM MgCl2, 0.1 mM EDTA, 0.5 mM DTT, 2% glycerol, 40 μg/ml BSA, 5 μM dATP, 5 μM dCTP, 5 μM dGTP, 1 μM digoxigenin-11-dUTP, and E9/A20/D4 proteins. The TNT reticulocyte lysate or in vitro translated luciferase was used as a negative control. After incubation at 37° C. for 30 min, the plate was washed extensively with phosphate-buffered saline (PBS). The wells were then incubated with anti-digoxigenin-peroxidase antibody (Roche) for 1 h at 37° C., followed by washing with PBS. The substrate 2,2′-azino-bis(3-ethylbenzthiazoline)-sulfonate (Roche) was added, and plates were gently rocked to allow color development. DNA synthesis was quantified by measuring the absorbance of each reaction at 405 nm with a microplate reader (Tecan).
- ROR gamma SPA Binding Assay The binding of potential ligands to RORγ is measured by competition with [3H]25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA) binding assay. The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromatography. 15 ug/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 μM to 0.28 nM for 10 min at room temperature in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% Glycerol (Sigma Cat# G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat # RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer). The competition data of the test compound over a range of concentrations was plotted as percentage inhibition of radioligand specifically bound in the absence of test compound (percent of total signal). After correcting for non-specific binding, IC50 values were determined. The IC50 value is defined as the concentration of test compound needed to reduce [3H] 25-hydroxycholesterol specific binding by 50% and is calculated using the four parameter logistic equation to fit the normalized data.
- Radioligand Binding Assay Compounds of the invention were assessed in a competition binding assay where different concentrations of compounds were incubated with the LXR ligand binding domain (LBD) in the presence of radiolabeled LXR ligand [3H]T0901317. The amount of the LXR-LBD that complexed with [3H]T0901317 was measured by scintillation proximity assay (SPA) employing non-specific binding of LXR-LBD to poly-lysine coated Yttrium silicate beads. Partially purified LXR α or β LBD protein (15-45 nM) was incubated at rt for 30 min with 15 nM [3H]T0901317 (25-40 Ci/mmol) and different concentrations of test compounds in 80 μL of phosphate buffered saline (PBS) buffer containing 2.5% DMSO, 1% glycerol, 2 mM EDTA, 2 mM CHAPS and 5 mM DTT in 96-well plates. Poly-lysine SPA beads (50 μg) were added to each well and the total volume was adjusted to 120 μL. The plates were shaken on an orbital shaker for 20 min and then allowed to settle for 10 more minutes at rt before a brief centrifugation at 2,000 rpm for 1 min. The SPA signal was measured on a MicroBeta® liquid scintillation counter (Perkin Elmer, Waltham, MA), and the results were used for calculating IC50 values based on the total binding (DMSO control) and non-specific binding (5 μM of unlabeled T0901317) controls.
- Radioligand Binding Assay In the GR radioligand binding assay, test compounds were serially diluted in semi-log steps (10 concentrations) with a final concentration of 10 μM. Test compounds (1 μL) and controls (1 μL) in 100% DMSO were added to 96 Greiner V-bottom polypropylene plates. 0% control was 6.7% DMSO (final concentration in assay) and 100% control was 6.7 μM Dexamethasone.The full length GR was diluted to a final concentration of 3.3% (0.495 mg/ml) in assay buffer (20 mM Tris-HCl, 1 mM EDTA, 10% (w/v) Glycerol, 20 mM Sodium molybdate, pH 7.4). 45 μL of GR was added to each well and the plates were incubated for 15 min at room temperature. 3H-dexamethasone solution was diluted to a concentration of 70 nM in assay buffer (7 nM final assay concentration) and 5 μL was added to each well. The samples were mixed for 5 min using a plate shaker at 700 rpm, before incubation for 2 h at room temperature.50 μL ice-cold charcoal solution (pH 7.4: 2% Charcoal, 0.2% Dextran T70 in 20 mM Tris-HCl, 1 mM EDTA and 20 mM Sodium molybdate) was added to each well and the samples were mixed on plate shaker for 5 minutes.
- SPA Assay The assays were performed in U-bottom 384-well optiplates. The final assay volume was 15 μl prepared from 7.5 μl additions of microsomes (prepared as a high-speed pellet from homogenized HEK2 cells stably transfected with CYP17), substrates (3H-Pregnenolone and NADPH) and test compounds in assay buffer (50 mM Potassium phosphate pH 7.2, 10% glycerol). The reaction was initiated by the combination of the microsomes and substrates in wells containing compound. The reaction was incubated at room temperature for 45 minutes and terminated by adding 7.5 μl of 0.2N HCl to each well. Following an incubation period of 10 minutes, anti-DHEA-coated SPA beads were added to the terminated reaction. The plate was sealed and incubated overnight with shaking at 4° C. The beads were allowed to settle in the plate for 1 hour and the plate read on a TOPCOUNT® (Perkin-Elmer) plate reader.Inhibition data were calculated by comparison to no enzyme control reactions for 100% inhibition and vehicle-only reactions for 0% inhibition. The final concentration of reagents in the assays are NADPH, 2 mM; 3H-Pregnenolone, 1 uM; microsomes, 1.25 ug/ml; Anti-DHEA-SPA beads (0.125 mg/well) in 0.5% Triton X-100 and DMSO, 0.05%. Dose response curves were generated to determine the concentration required inhibiting 50% of enzyme activity (IC50). Compounds were dissolved at 10 mM in dimethylsulfoxide (DMSO) and evaluated at eleven concentrations, each in duplicate. IC50 values were derived by non-linear regression analysis.
- Scintillation Proximity Assay (SPA) The binding of potential ligands to RORγ is measured by competition with [3H] 25-hydroxycholesterol (Perkin Elmer NET674250UC) using a scintillation proximity assay (SPA) binding assay. The ligand binding domain of human RORγ (A262-S507) with an N-terminal His tag is expressed in E. coli and purified using nickel affinity chromatography. 15 ug/well RORγ (A262-S507) is incubated with test compound at varying concentrations in 3-fold serial dilution, with final concentrations ranging from 16.6 uM to 0.28 nM for 10 min at room temperature in PBS buffer (Invitrogen #14190-144) containing 0.5% fatty acid free BSA (Gemini Bio-Products, Cat. #700-107P) and 0.1% Glycerol (Sigma Cat#G5516). 10 nM of [3H] 25-hydroxycholesterol is then added, and the reaction is incubated for 10 min. 10 mg/mL of Copper-His Tag-PVT beads (Perkin Elmer cat #RPNQ0095) are added, and the mixture is incubated for 60 min. The reaction is read on a TopCount Microplate scintillation plate reader (Perkin Elmer). The competition data of the test compound over a range of concentrations was plotted as percentage inhibition of radioligand specifically bound in the absence of test compound (percent of total signal). After correcting for non-specific binding, IC50 values were determined. The IC50 value is defined as the concentration of test compound needed to reduce [3H] 25-hydroxycholesterol specific binding by 50% and is calculated using the four parameter logistic equation to fit the normalized data.
- Surface Plasmon Resonance (SPR) Binding Surface plasmon resonance (SPR) STING agonist binding studies were carried out using a Biacore T200 instrument (GE Healthcare) at 4° C. in a 150 mM KCl, 25 mM Hepes (pH 7.5), 1 mM TCEP, 2.5 mM MgCl2, 5% (v/v) glycerol, 0.005% (v/v) P20, 1% (v/v) DMSO running buffer. The recombinant protein immobilized on the streptavidin chip was either human WT or H232R STING. A truncated construct of STING was used in all studies. The STING constructs were comprised of residues 155-341 with both N- and C-terminal truncations; the N-terminal transmembrane domains were removed (1-154), as well as the C-terminal tail (342-379). A highly specific N-terminal biotinylation was achieved enzymatically with the E. coli biotin ligase (BirA) and inclusion of the high-affinity biotinylation peptide AviTag™. A Carboxymethylated dextran pre-immobilized with streptavidin (series S Streptavidin CM5 Sensor Chip) was used to capture the biotinylated STING protein. Test compound injections were made at a flow rate of 100 μl per minute with a 60 second association time and variable dissociation time. A three-fold dilution series from a 10 μM starting concentration was used for all test compounds. Data analysis was performed using the BiacoreT200 data evaluation software package (GE Healthcare).
- Time-Resolved Endpoint Proteolysis Assay BACE-2: Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are preincubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- Time-Resolved Endpoint Proteolysis Assay BACE-2: Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are preincubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 s delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- Time-Resolved Endpoint Proteolysis Assay BACE2: Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are preincubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration. Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- Time-Resolved Endpoint Proteolysis Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (SEQ ID 1) (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1× BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (SEQ ID 1) (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- Time-Resolved Endpoint Proteolysis aAssay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- ASK1 Inhibitor Effect Determined by ASK1 Enzymatic Assay The purpose of this assay is to determine the effect of ASK1 inhibitors on the production of ADP by ASK1. The recombinant human ASK1 (hASK1) catalytic domain tagged with Glutathione S-transferase is used, and histidine-tagged full-length human MAP kinase kinase 6 (MKK6) and ATP are the substrate and cofactor, respectively.The assay is done using an ADP-Glo™ Kinase Assay Kit (Promega, Catalog #V9102) according to the manufacturer's protocol with the following modifications. Briefly, hASK1 (0.25 nM) and MKK6 (300 nM) in a buffer (10 mM MOPS pH 7.0; 10 mM Mg-Acetate; 1 mM DTT; 0.025% NP-40; 0.05% BSA; 1.5% glycerol) are incubated with ASK1 inhibitors at varying concentrations ranging from 10.00 uM to 0.17 nM for 15 minutes, followed by incubation with ATP (100 uM) for 30 minutes at room temperature. ADP-Glo™ Reagent is added to terminate the kinase reaction and deplete the remaining ATP. The Kinase Detection Reagent is then added to convert ADP to ATP. The newly synthesized ATP is measured using a luciferase/luciferin reaction, and the luminescence determined by Envision (PerkinElmer). The luminescence intensities are analyzed by GeneData, and fit to a 4 parameter dose response-inhibitor logistics curve to determine IC50 values, using the effects of 5-(4-cyclopropyl-1H-imidazol-1-yl)-2-fluoro-4-methyl-N-{6-[4-(propan-2-yl)-4H-1,2,4-triazol-3-yl]pyridin-2-yl}benzamide as a standard and DMSO vehicle for 100% and 0% inhibition, respectively.
- BACE-2 Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50s are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively.
- BACE-2 Assay The compounds of the invention were determined to be potent inhibitors of BACE-2 using the following assay. Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values.
- DNA Methylation Assay Assays (0.1 ml) were conducted in 96-well black half-area plates in either a Wallac VICTOR2 or Biotek Synergy Neo plate reader at 37 °C in 10 mM Tris, pH 7.5, 100 mM potassium glutamate, 1 mM MgCl2, 1 mM DTT, 0.1 mg/ml BSA, and 5% glycerol. Assays contained varying amounts of oligonucleotide 8006 (5'-FAM-CCTATGCGmCATCAGTTTTCTGATGmCGmCATAGG-3'-Iowa Black, in which mC denotes 5-methyldeoxycytidylate residues (Integrated DNA Technologies, Coralville, IA), AdoMet (HPLC-purified, Sigma), and small molecule inhibitors (5-azaC, Sigma; SGI-1027, generous gift of Dr. Jian Jin, University of North Carolina; LCA, TCI America). Other anthraquinone compounds examined were purchased from ChemBridge Corp, San Diego, CA (UI1055 is N,N-diethyl-1-nitro-9,10-dioxo-9,10-dihydroanthracene-2-carboxamide; UI1060 is ethyl N-{[1-(butylthio)-9,10-dioxo-9,10-dihydroanthra-cen-2-yl] carbonyl}glycinate; UI1061 is 1-(butylsulfonyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid) and Sigma (anthraquinon and anthraquinone 2-carboxylic acid). All assays were conducted in triplicate and contained either human Dnmt1 (621-1600), human Dnmt1 (351-1600), human Dnmt3a (590-912), or M.SssI methyltransferase (New England Biolabs) and 0.8 units of Gla I (Sibenzyme, West RoxRoxbury, MA), except for the Gla I control assay, which did not contain a methyltransferase. Data were fitted using Prism (GraphPad Software, Inc).
- FAAH Assay 1 T84 frozen cell pellets or transfected SK-N-MC cells (contents of 1×15 cm culture dishes) were homogenized in 50 mL of FAAH assay buffer (125 mM Tris, 1 mM EDTA, 0.2% Glycerol, 0.02% Triton X-100, 0.4 mM Hepes, pH 9). The assay mixture consisted of 50 μL of the cell homogenate, 10 μL of the test compound, and 40 μL of anandamide [1-3H-ethanolamine] (3H-AEA, Perkin-Elmer, 10.3 Ci/mmol), which was added last, for a final tracer concentration of 80 nM. The reaction mixture was incubated at rt for 1 h. During the incubation, 96-well Multiscreen filter plates (catalog number MAFCNOB50; Millipore, Bedford, Mass., USA) were loaded with 25 μL of activated charcoal (Multiscreen column loader, catalog number MACL09625, Millipore) and washed once with 100 μL of MeOH. Also during the incubation, 96-well DYNEX MicroLite plates (catalog number NL510410) were loaded with 100 μL of MicroScint40 (catalog number 6013641, Packard Bioscience, Meriden, Conn., USA). After the 1 h incubation, 60 μL of the reaction mixture were transferred to the charcoal plates, which were then assembled on top of the DYNEX plates using Centrifuge Alignment Frames (catalog number MACF09604, Millipore). The unbound labeled ethanolamine was centrifuged through to the bottom plate (5 min at 2000 rpm), which was preloaded with the scintillant, as described above. The plates were sealed and left at rt for 1 h before counting on a Hewlett Packard TopCount.
- FAAH Assay 2 Transfected SK-N-MC cells (contents of 1×15 cm culture dishes) were homogenized in 50 mL of FAAH assay buffer (125 mM Tris, 1 mM EDTA, 0.2% Glycerol, 0.02% Triton X-100, 0.4 mM Hepes, pH 9). The assay mixture consisted of 50 μL of the cell homogenate, 10 μL of the test compound, and 40 μL of anandamide [1-3H-ethanolamine] (3H-AEA, Perkin-Elmer, 10.3 Ci/mmol), which was added last, for a final tracer concentration of 80 nM. The reaction mixture was incubated at rt for 1 h. During the incubation, 96-well Multiscreen filter plates (catalog number MAFCNOB50; Millipore, Bedford, Mass., USA) were loaded with 25 μg of activated charcoal (Multiscreen column loader, catalog number MACL09625, Millipore) and washed once with 100 μL of MeOH. Also during the incubation, 96-well DYNEX MicroLite plates (catalog number NL510410) were loaded with 100 μL of MicroScint40 (catalog number 6013641, Packard Bioscience, Meriden, Conn., USA). After the 1 h incubation, 60 μL of the reaction mixture were transferred to the charcoal plates, which were then assembled on top of the DYNEX plates using Centrifuge Alignment Frames (catalog number MACF09604, Millipore). The unbound labeled ethanolamine was centrifuged through to the bottom plate (5 min at 2000 rpm), which was preloaded with the scintillant, as described above. The plates were sealed and left at rt for 1 h before counting on a Hewlett Packard TopCount.
- FLAP Binding Assay (Test A) Compounds were tested in a competition binding assay using 3H-MK591 as tracer. (Preparation of MK-591 is described in Bioorg. Med. Chem. Lett. 1999, 9, 2391). A 100,000×g pellet from COS-7 cells stably transfected with a plasmid expressing human ALOX5AP was the source of FLAP. Membrane pellets were resuspended in buffer (100 mM Tris-HCl, 0.05% Tween-20, 140 mM NaCl, 2 mM EDTA, 0.5 mM DTT, 5% Glycerol, pH 7.5) to give a final protein concentration of 12 mg/mL (2 μg/well). To perform assays, 1.4 μL compounds were dispensed into 96-well plates in 3-fold dilution series in triplicate. 84 μL radioligand (25000 CPM, 2 nM final concentration in assay) was then added followed by 84 μL membrane suspension and incubation at rt for 60 min. Following filtration, filter plates were dried 12 h at RT (or 50° C. for 1 hour). 50 μL scintillant was then added, the filterplates were sealed and radioactivity was measured in a microbeta counter. Specific binding was defined as total binding minus non-specific binding. Total binding was defined as 3H-MK591 bound to membranes in the absence of competitor, non-specific binding was defined as 3H-MK591 in the presence of 0.1 mM MK-591. IC50 values were determined by plotting % inhibition versus log compound concentration and using a one site dose response model.
- HTRF Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50s are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively.
- HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves.
- IDO1 Enzyme Assay HIS-tagged IDO1 protein was recombinantly expressed in Escherichia coli using ZYP5052 autoinduction media supplemented with 500 μM delta aminolevulinic acid for 48 hours at 16 degrees Celcius. IDO1 protein was purified using Ni2+-affinity resin and size exclusion chromatography. Purified protein was then diluted in assay buffer (50 mM Tris pH 7.0, 1% glycerol, 20 μM methylene blue, 0.05% Tween-20, 20 mM sodium ascorbate, 100 units/mL catalase to obtain a final IDO1 concentration of 40 nM. IDO1 solution (30 μM) or buffer alone (30 μM) were dispensed to wells of the assay plate using a BioRAPTR liquid dispenser (Beckman Coulter). Assay plates containing compound and IDO1 enzyme were incubated at room temperature for 30 minutes. Afterwards, 10 μL of 400 μM tryptophan in assay buffer were added to each well of the assay plate using a BioRAPTR liquid dispenser. Plates were incubated at room temperature for 60 minutes and reactions were quenched by addition of 10 μL of 0.5 M methyl isonipecotate in dimethyl sulfoxide. Plates were sealed and incubated at 37 degrees Celcius for 4 hours or 50 degrees Celcius for 2 hours. The plates are allowed to cool and then centrifuged for 1 minute at 1000×g. The resulting fluoresence was measured in an Envision plate reader (Perkin Elmer) with a 400/25 nm excitation filter and an 510/20 nm emission filter.
- In Vitro Assay A test compound is prepared as 10 mM stock in DMSO and diluted to 50× final concentration in DMSO, for a 50 μl reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutaric acid is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH1-R132 homodimer enzyme is diluted to 0.125 μg/ml in 40 μl of Assay Buffer (150 mM NaCl, 20 mM Tris-Cl pH 7.5, 10 mM MgCl2, 0.05% BSA, 2 mM b-mercaptoethanol); 1 μl of test compound dilution in DMSO is added and the mixture is incubated for 60 minutes at room temperature. The reaction is started with the addition of 10 μl of Substrate Mix (20 μl NADPH, 5 mM alpha-ketoglutarate, in Assay Buffer) and the mixture is incubated for 90 minutes at room temperature. The reaction is terminated with the addition of 25 μl of Detection Buffer (36 μg/ml diaphorase, 30 mM resazurin, in 1× Assay Buffer), and is incubated for 1 minute before reading on a SpectraMax platereader at Ex544/Em590.Compounds are assayed for their activity against IDH1 R132C following the same assay as above with the following modifications: Assay Buffer is (50 mM potassium phosphate, pH 6.5; 40 mM sodium carbonate, 5 mM MgCl2, 10% glycerol, 2 mM b-mercaptoethanol, and 0.03% BSA). The concentration of NADPH and alpha-ketoglutarate in the Substrate Buffer is 20 μM and 1 mM, respectively.
- In Vitro Assay The method employed was adapted from the scientific literature and described in detail by Osbourn et al. (1993, Biochemistry, 32, 6229-6236). Recombinant human ERα and ERβ proteins were purified from transfected Sf9-cells. The in vitro assays involved the use of either ERα or ERβ proteins and [3H]E2, at a fixed concentration of 0.5 nM, as the labeled ligand. Recombinant human ERα or ERβ proteins were dissolved in binding buffer (10 mM Tris-HCL, pH 7.5, 10% glycerol, 1 mM DTT, 1 mg/ml BSA) and duplicate aliquots were then incubated with [3H]E2 at a final concentration of 0.5 nM, together with a vehicle control (0.4% DMSO), or the same amount of vehicle containing increasing concentrations of unlabeled steroid ligands as competitors. After incubation for 2 h at 25° C., the unbound ligands were removed and the amounts of [3H]E2 bound to either ERα or ERβ proteins were measured. The average amounts of [3H]E2 bound to either ERα or ERβ proteins at each concentration of competitor were used to make inhibition curves. IC50 values were subsequently determined by a non-linear, least squares regression analysis. Inhibition constants (Ki) were calculated using the equation of Cheng and Prusoff (Cheng et al., 1973, Biochem. Pharmacol., 22, 3099-3108), using the measured IC50 of the tested compounds, the concentration of radioligand employed in the assay, and the historical values for the Kd of the radioligand, which were established as 0.2 nM and 0.13 nM for ERα and ERβ, respectively.
- In Vitro Assays A test compound is prepared as 10 mM stock in DMSO and diluted to 50× final concentration in DMSO, for a 50 μl reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutaric acid is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH1-R132 homodimer enzyme is diluted to 0.125 μg/ml in 40 μl of Assay Buffer (150 mM NaCl, 20 mM Tris-Cl pH 7.5, 10 mM MgCl2, 0.05% BSA, 2 mM b-mercaptoethanol); 1 μl of test compound dilution in DMSO is added and the mixture is incubated for 60 minutes at room temperature. The reaction is started with the addition of 10 μl of Substrate Mix (20 μl NADPH, 5 mM alpha-ketoglutarate, in Assay Buffer) and the mixture is incubated for 90 minutes at room temperature. The reaction is terminated with the addition of 25 μl of Detection Buffer (36 μg/ml diaphorase, 30 mM resazurin, in 1× Assay Buffer), and is incubated for 1 minute before reading on a SpectraMax platereader at Ex544/Em590.Compounds are assayed for their activity against IDH1 R132C following the same assay as above with the following modifications: Assay Buffer is (50 mM potassium phosphate, pH 6.5; 40 mM sodium carbonate, 5 mM MgCl2, 10% glycerol, 2 mM b-mercaptoethanol, and 0.03% BSA). The concentration of NADPH and alpha-ketoglutarate in the Substrate Buffer is 20 μM and 1 mM, respectively.
- In Vitro Assays for IDH1m (R132H or R132C) Inhibitors A test compound is prepared as 10 mM stock in DMSO and diluted to 50× final concentration in DMSO, for a 50 μl reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutaric acid is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH1-R132 homodimer enzyme is diluted to 0.125 μg/ml in 40 of Assay Buffer (150 mM NaCl, 20 mM Tris-C1 pH 7.5, 10 mM MgCl2, 0.05% BSA, 2 mM b-mercaptoethanol); 1 μl of test compound dilution in DMSO is added and the mixture is incubated for 60 minutes at room temperature. The reaction is started with the addition of 10 of Substrate Mix (20 μl NADPH, 5 mM alpha-ketoglutarate, in Assay Buffer) and the mixture is incubated for 90 minutes at room temperature. The reaction is terminated with the addition of 25 μl of Detection Buffer (36 μg/ml diaphorase, 30 mM resazurin, in 1× Assay Buffer), and is incubated for 1 minute before reading on a SpectraMax platereader at Ex544/Em590.Compounds are assayed for their activity against IDH1 R132C following the same assay as above with the following modifications: Assay Buffer is (50 mM potassium phosphate, pH 6.5; 40 mM sodium carbonate, 5 mM MgCl2, 10% glycerol, 2 mM b-mercaptoethanol, and 0.03% BSA). The concentration of NADPH and alpha-ketoglutarate in the Substrate Buffer is 20 μM and 1 mM, respectively.
- In Vitro DGAT2 Assay For determination of IC50 values, the reactions were carried out in 384-well white Polyplates (Perkin Elmer) in a total volume of 20 μL. To 14 of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 μL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 20 minutes. To this mixture, 10 μL of hDGAT2 membrane fraction (0.01 mg/mL) diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical; dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock) was added. After this mixture was preincubated at room temperature for 2 hours, DGAT2 reactions were initiated by the addition of 4 μL of substrates containing 30 μM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 μM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 μL of 1% H3PO4. After the addition of 45 μL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.).
- LCMS Assay The MGAT enzyme reactions were performed in Corning FALCON® 96-well Polypropylene plates, in a total volume of 60 μL of 50 mM Potassium Phosphate buffer pH 7.4, containing a final concentration of 100 μM 2-oleoylglycerol, 15 μM oleoyl-Coenzyme A and 0.0013 μg/μL Human or Mouse MGAT-2 or 0.0026 μg/μL Rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 μL of ice cold methanol containing 1 μg/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters Symmetry C8, 50×2.1 mm column, was used for the chromatography of enzyme products. The buffer system consists of 0.1% formic acid in water with a mobile phase consisting 0.1% formic acid in methanol. The shallow gradient is 90-100% mobile phase in 0.2 min with a total run time of 2.3 min. The first 0.5 minutes of each injection was diverted to waste to eliminate the presence of Phosphate buffer in the enzymatic reaction. The column was run at 0.6 mL/min and a temperature of 65° C.
- LCMS Assay The MGAT enzyme reactions were performed in Corning FALCON® 96-well Polypropylene plates, in a total volume of 60 μL of 50 mM Potassium Phosphate buffer pH 7.4, containing a final concentration of 100 μM 2-oleoylglycerol, 15 μM oleoyl-Coenzyme A and 0.0013 μg/μL Human or Mouse MGAT-2 or 0.0026 μg/μL Rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 μL of ice cold methanol containing 1 μg/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters Symmetry C8, 50×2.1 mm column, was used for the chromatography of enzyme products. The buffer system consists of 0.1% formic acid in water with a mobile phase consisting 0.1% formic acid in methanol. The shallow gradient is 90-100% mobile phase in 0.2 min with a total run time of 2.3 min. The first 0.5 minutes of each injection was diverted to waste to eliminate the presence of Phosphate buffer in the enzymatic reaction. The column was run at 0.6 mL/min and a temperature of 65° C. Mass spectrometry analysis of the samples was performed on a ThermoFisher Quantum Triple quad utilizing APCI (+) as the mode of ionization.
- Luciferase Assay The stock cultures are grown, at 37° C. and under 5% CO2, in DMEM/F12 medium containing 10% FCS (fetal calf serum) and in each case split 1:10 after 2-3 days. Test cultures are seeded in 384-well plates with 2000 cells per well and grown at 37° C. for approx. 48 hours. The medium is then replaced with a physiological sodium chloride solution (130 mM sodium chloride, 5 mM potassium chloride, 2 mM calcium chloride, 20 mM HEPES, 1 mM magnesium chloride hexahydrate, 5 mM sodium bicarbonate, pH 7.4). The substances to be tested, which are dissolved in DMSO, are pipetted into the test cultures (maximum final concentration of DMSO in the test mixture: 0.5%) in a dilution series of from 5x10-11 M to 3x10-6 M (final concentration). 10 minutes later, forskolin is added to the A1 cells and all the cultures are subsequently incubated at 37° C. for four hours. After that, 35 ul of a solution which is composed of 50% lysis reagent (30 mM disodium hydrogenphosphate, 10% glycerol, 3% TritonX100, 25 mM TrisHCl, 2 mM dithiotreitol (DTT), pH 7.8) and 50% luciferase substrate solution (2.5 mM ATP, 0.5 mM luciferin, 0.1 mM coenzyme A, 10 mM tricine, 1.35 mM magnesium sulfate, 15 mM DTT, pH 7.8) are added to the test cultures, which are shaken for approx. 1 minute and the luciferase activity is measured using a camera system.
- Omnia Assay Briefly, 10x stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13xATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1x kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM beta-glycerophosphate, 5% glycerol (10x stock, KB002A) and 0.2 mM DTT (DS001A). 5 uL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 uL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at lamda ex360/lamda em485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to 30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).
- Omnia Assay Briefly, 10x stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 27° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 30-90 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).
- Omnia Assay Protocol for Potency Assessment Against BTK Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM 3-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 27° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 30-90 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).
- Scintillation Proximity Assay (SPA) HIF-2a: The total assay volume was about 100 uL in the following configuration: 2 uL compound in 100% DMSO, 88 uL buffer with protein and probe and 10 uL of SPA beads. The compound was diluted in a master plate consisting of a 10-point dose response with a 3-fold compound dilution from 100 nM to 5 nM. Assays were run on a 96-well plate in which one column, designated as the high signal control, contained DMSO with no compound and another column, designated as the low signal control, contained no protein. Prior to plating out of compound, a buffer solution, consisting of 25 mM TRIS pH 7.5 (Sigma), 150 mM NaCl (Sigma), 15% Glycerol (Sigma), 0.15% BSA (Sigma), 0.001% Tween-20 (Sigma), 150 nM Compound 183 and 100 nM HIF-2α HIS TAG-PASB Domain, was made and allowed to equilibrate for 30 minutes. Compounds that were to be tested were then plated in to a 96-well white clear bottom Isoplate-96 SPA plate (Perkin Elmer). To the compounds, 88 uL of the buffer solution was then added, the plate was covered with a plastic cover and then aluminum foil, placed onto a shaker and equilibrated for 1 hour. After equilibration, 10 uL of a 2 mg/mL solution of YSi Cu His tagged SPA beads (Perkin Elmer) were then added to each well of the plate, covered and equilibrated for another 2 hours. The plates were then removed from the shaker, placed into a 1450 LSC and luminescence counter MicroBeta Trilux (Perkin Elmer) to measure the extent of probe displacement.
- Scintillation Proximity Assay (SPA) The total assay volume was about 100 μL in the following configuration: 2-μL compound in DMSO, 88 μL buffer with protein and probe and 10 μL of SPA beads. The compound was diluted in a master plate consisting of a 10-point dose response with a 3-fold compound dilution from 100 μM to 5 nM. Assays were run on a 96-well plate in which one column, designated as the high signal control, contained DMSO with no compound and another column, designated as the low signal control, contained no protein. Prior to plating out of a compound, a buffer solution, containing 25 mM TRIS pH 7.5 (Sigma), 150 mM NaCl (Sigma), 15% Glycerol (Sigma), 0.15% BSA (Sigma), 0.001% Tween-20 (Sigma), 150 nM Compound 120 and 100 nM HIF-2α HIS TAG-PASB Domain, was prepared and allowed to equilibrate for 30 minutes. Compounds that were to be tested were then plated in to a 96-well white clear bottom Isoplate-96 SPA plate (Perkin Elmer). To each compound, 88 μL of the buffer solution was then added. The plate was covered with a plastic cover and then aluminum foil, placed onto a shaker and equilibrated for 1 hour. After equilibration, 10 μL of a 2 mg/mL solution of YSi Cu His tagged SPA beads (Perkin Elmer) were then added to each well of the plate, covered and equilibrated for another 2-hours. The plates were then removed from the shaker, placed into a 1450 LSC and luminescence counter MicroBeta Trilux (Perkin Elmer) to measure the extent of probe displacement.
- TR-FRET ASK1 kinase assay The assay measures the phosphorylation level of a biotinylated peptide substrate by the ASK1 kinase using HTRF detection (6.1). This is a competitive, time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay, based on HTRF® KinEASE™-STK manual from Cisbio (6.1). Test compound, 1 μM STK3 peptide substrate, 4 nM of ASK1 kinase are incubated with 10 mM MOP buffer, pH. 7.0 containing 10 mM Mg-acetate, 0.025% NP-40, 1 mM DTT, 0.05% BSA and 1.5% glycerol for 30 minutes then 100 μM ATP is added to start the kinase reaction and incubated for 3 hr. Peptide antibody labeled with 1×Eu3+ Cryptate buffer containing 10 mM EDTA and 125 nM Streptavidin XL665 are added to stop the reaction and phosphorylated peptide substrate is detected using Envision 2103 Multilabeled reader from PerkinElmer. The fluorescence is measured at 615 nm (Cryptate) and 665 nm (XL665) and a ratio of 665 nm/615 nm is calculated for each well. The resulting TR-FRET level (a ratio of 665 nm/615 nm) is proportional to the phosphorylation level. Under these assay conditions, the degree of phosphorylation of peptide substrate was linear with time and concentration for the enzyme. The assay system yielded consistent results with regard to Km and specific activities for the enzyme. For inhibition experiments (IC50 values), activities were performed with constant concentrations of ATP, peptide and several fixed concentrations of inhibitors. Staurosporine, the nonselective kinase inhibitor, was used as the positive control. All enzyme activity data are reported as an average of quadruplicate determination.
- TR-FRET PI3K Beta Assay Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2× Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 μM, and PI3Kγ at 2 nM. The compounds were added to the assay solution and incubated for 30 minutes at 25° C. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 μs delay and 500 μs read window).The results were normalized based on positive (1 μM wortmanin) and negative (DMSO) controls, and the IC50 values for PI3K α, β, δ, and γ were calculated from the fit of the dose-response curves to a four-parameter equation. These assays generally produced results within 3-fold of the reported mean. As shown in Table 1, the compounds provided herein are inhibitors of PI3Kβ.
- BACE-2 Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 M for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50s are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s are obtained when using raw RFU data. The Ki values are calculated from the IC50 using the Cheng-Prusoff equation.
- BACE-2 Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 LM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50s are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s are obtained when using raw RFU data. The Ki values are calculated from the IC50 using the Cheng-Prusoff equation.
- BACE-2 Assay Inhibitor IC50s, at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1× BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1×BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 μs delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50 values are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s are obtained when using raw RFU data. The Ki values are calculated from the IC50 using the Cheng-Prusoff equation.
- BACE1 HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined μm value of 8 μM for the QSY7-APPswe-Eu substrate at BACE1.
- BACE1 HTRF FRET Assay This assay monitored the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contained an N-terminal QSY7 moiety that served as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence was low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors was manifested as a suppression of 620 nm fluorescence. Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul were preincubated with purified human BACE1 catalytic domain (3 nM in 10 Ml) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions were initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions were incubated at 30° C. for 1.5 hours. The 620 nm fluorescence was then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 μs delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values were derived from non-linear regression analysis of concentration response curves. Ki values were then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined m value of 8 μM for the QSY7-APPswe-Eu substrate at BACE1.
- Binding Assay Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. # T2320).
- Binding Assay A human STING [3H] 2′,3′-cGAMP scintillation proximity competition binding assay was utilized to detect binding of compounds to STING protein. The competition binding assay was conducted with either a wild-type (WT, SEQ ID NO: 1) or an AQ variant (SEQ ID NO: 2) of truncated human STING protein that lacks the N-terminal four transmembrane domains and contains amino acids 155-379. The protein encoding plasmid contained a HIS tag, followed by an Avi tag and then a SUMO tag, which were followed by the STING coding sequence within the pET-28a (+) vector. The plasmid was transfected into a BL21 (DE3)/BirA E. coli co-expression strain. Protein was purified from the bacterial lysate using a cobalt-affinity column. The purified protein was dialyzed against PBS and then 20% glycerol was added prior to storage at −80° C.The assay was conducted in a 384-well plate containing final concentration of 25 nM biotin-STING protein and 17.5 nM [3H] 2′,3′-cGAMP in assay buffer (50 mM Tris pH 7.5, 100 mM NaCl, 0.1% Fatty Acid Free BSA). Test compounds (2.5 μL) were added to the plate first followed by a 25 μL mixture of STING protein, streptavidin PVT SPA beads (Perkin Elmer) and 10 μL [3H] 2′,3′-cGAMP. Plates were incubated at room temperature for 18 hrs and read on a Wallac MicroBeta TriLux (Perkin Elmer). 2′,2′-cGAMP was used as a reference compound and had an IC50 of 0.562 μM using the WT STING protein and 0.098 M using the AQ STING protein.
- Binding Assay Compounds of the present invention were tested for ability to bind to ROR in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant RORFigure US09796710-20171024-P00001Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORFigure US09796710-20171024-P00001LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORFigure US09796710-20171024-P00001 inverse agonist T0901317 (SigmaAldrich, Cat. # T2320).
- Enzyme Assay Purified human glycoprotein IIb/IIIa (20 mM Tris-HCl, 0.1 M NaCl, 0.1% Triton X-100, 1 mM CaCl2, 0.05% NaN3, 50% Glycerol, pH 7.4) was purchased from Enzyme Research Laboratories Inc. (South Bend, Ind.). The GPIIb/IIIa receptor was diluted in phosphate-buffered saline (Dulbecco's Phosphate Buffered Saline (D-PBS (+)) with calcium and magnesium, GIBCO®, Invitrogen) with 0.01% bovine serum albumin (albumin from bovine serum-lyophilized powder, >96%, Sigma).The GPIIb/IIIa receptor was immobilized 48 hours at least (100 μL per well, 48 to maximum 96 hours) on a 96-well solid plate (Immuno Plate MaxiSorp, Nunc, Roskilde, Denmark) at 277 K to 280 K and at a concentration of 0.1 μg per well to 1 μg per well. As negative control one row of the plate (n=8) was incubated just with 2% bovine serum albumin (200 μL per well, albumin from bovine serum-lyophilized powder, >96%, Sigma, diluted in D-PBS (+)).After washing three times with the wash buffer (230 μL per well, Dulbecco's Phosphate Buffered Saline (D-PBS (−)) contains no calcium or magnesium, GIBCO®, Invitrogen) residual exposed plastic and unspecific binding sites were blocked by incubating the plate with a special blocking solution (200 μL per well, Roti®-Block, Carl Roth GmbH Co KG, Karlsruhe) containing 2% bovine serum albumin (Albumin from bovine serum-lyophilized powder, >96%, Sigma) 1 hour at room temperature.
- Enzyme Assay Rat and human nNOS, murine macrophage iNOS, and human eNOS were recombinant enzymes (expressed in E. coli and purified as reported previously in the literature). To test for NOS inhibition, the hemoglobin capture assay was used to measure nitric oxide production. The assay was performed at 37° C. in HEPES buffer (100 mM with 10% glycerol, pH 7.4) in the presence of 10 μM L-arginine. Also included were 100 μM NADPH, 0.83 mM CaCl2, approximately 320 units/mL of calmodulin, 10 μM H4B, and human oxyhemoglobin (3 μM). For iNOS, the CaCl2 and calmodulin were omitted and replaced with HEPES buffer (neither are required for activation of iNOS). The assay was performed in 96-well plates using a Synergy 4 BioTek hybrid reader. The dispensing of NOS enzyme and hemoglobin were automated, and after 30 sec (maximum delay), NO production was read by monitoring the absorbance at 401 nm (resulting from conversion of oxyhemoglobin to methemoglobin). Kinetic readouts were performed for 5 min. Each compound was assayed at least in duplicate, and six to nine concentrations (500 μM-50 nM or 100 μM-10 nM for eNOS and iNOS; 50 μM to 5 nM for rat and human nNOS) were used to construct dose-response curves. IC50 values were calculated by non-linear regression (variable slope, four parameters) using GraphPad Prism software, and Ki values were obtained using the Cheng-Prusoff equation [Ki=IC50/(1+[S]/Km)] with the following Km values: 1.3 μM (rat nNOS), 1.6 μM (human nNOS), 8.2 μM (murine macrophage iNOS), and 3.9 (human eNOS).
- Enzyme Assays and Inhibition Studies Cloning and Expression of the 3CL Protease of SARS-CoV-2 and FRET Enzyme Assays. The codon-optimized cDNA of full length of 3CLpro of SARS-CoV-2 (GenBank number MN908947.3) fused with sequences encoding six histidines at the N-terminal was synthesized by Integrated DNA (Coralville, IA). The synthesized gene was subcloned into the pET-28a(+) vector. The expression and purification of SARS-CoV-2 3CLpro were conducted following a standard procedure described previously. Briefly, a stock solution of an inhibitor was prepared in DMSO and diluted in assay buffer composed of 20 mM HEPES buffer, pH 8, containing NaCl (200 mM), EDTA (0.4 mM), glycerol (60%), and 6 mM dithiothreitol. The SARS-CoV-2 protease was mixed with serial dilutions of the inhibitor or with DMSO in 25 μL of assay buffer and incubated at 37 °C for 1 h, followed by the addition of 25 μL of assay buffer containing the substrate (FAM-SAVLQ/SG-QXL520, AnaSpec, Fremont, CA). The substrate was derived from the cleavage sites on the viral polyproteins of SARS-CoV. Fluorescence readings were obtained using an excitation wavelength of 480 nm and an emission wavelength of 520 nm on a fluorescence microplate reader (FLx800; Biotec, Winoosk, VT) for 1 h following the addition of the substrate. Relative fluorescence units were determined by subtracting background values (substrate-containing well without protease) from the raw fluorescence values, as described previously.25 The dose-dependent FRET inhibition curves were fitted with a variable slope using GraphPad Prism software (GraphPad, La Jolla, CA) in order to determine the IC50 values of the compounds. The expression and purification of the 3CLpro of MERS-CoV and the FRET enzyme assays were performed as described previously.
- Enzyme Inhibition Assay Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C.Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Enzyme Inhibition Assay Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2), 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Enzyme Inhibition Assay Human ATX: Assay working solutions were made as follows: Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0; ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer; MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- FAAH Activity Hydrolysis of [3H]-AEA by FAAH was determined as previously described in cell homogenates of U937 cells (0.18 mg protein) (Omeir et al., 1999, Biochem Biophys Res Commun, 264, 316-20; Mor et al., 2004, J Med Chem, 47, 4998-5008). Protein amounts of cell homogenates corresponded to 0.5×106 cells (U937), to assure best possible comparability of IC50 values as used for the AEA cellular uptake assays. URB597 was used as positive control. Protein quantification was performed using a BCA assay (Thermo Scientific). Enzyme activity was assessed by addition of vehicle or compounds in 10 μL DMSO to 490 μL homogenate in 10 mM Tris HCl, 1 mM EDTA, 0.1% (w/v) BSA fatty acid free, pH=8 and incubation for 15 min at 37° C. After, a mixture of AEA plus [ethanolamine-1-3H]-AEA (0.5 nM) at final 100 nM was added to the homogenates and incubated for 15 min at 37° C. The reaction was stopped by addition of 1 mL ice-cold CHCl3:MeOH (1:1) followed by vigorous vortexing. Phase separation was achieved by centrifugation at 10′000×g at 4° C. for 10 min. Radioactivity of the separated aqueous phase (upper phase) containing [3H-ethanolamine] or [3H-glycerol] was measured by liquid scintillation counting on a Tri-Carb 2100 TR liquid scintillation analyzer after addition of 3.5 mL Ultima Gold scintillation cocktail (PerkinElmer Life Sciences). Results are expressed as hydrolysis of tritium substrate in percent of vehicle treated control. IC50 values were calculated by GraphPad®. Data are reported as means of n=3 independent experiments performed in triplicates.
- FLT3 Kinase Test FLT3 is obtained from Invitrogen in 50 mM Tris (pH7.5); 100 mM NaCl; 0.05 mM EDTA, 0.05% NP-40, 2 mM DTT; 50% Glycerol # PV3182; Lot 286671; sequence see below). The enzyme is diluted to 720 nM (35 μg/ml) in enzyme dilution buffer and 10 μl aliquots are stored at −80° C.The activity of FLT3 is measured using the Z′-LYTE™ assay technology from Invitrogen (#PV3191)MethodThe assay is performed in 384 black plates from Corning (#3676) in a final volume of 10 μl by adding 5 μl of kinase peptide mix and 2.5 μl of compound dilution. The reaction is started by addition of 2.5 μl of the 4×ATP solution.Final concentration in assay: FLT3 2 nM, Tyr2 peptide 4 μM, ATP 470 μM (ATP Km for FLT3)Positive controls are reaction mixtures containing no test compound; negative controls (blanks) are reaction mixtures containing no kinase. As a further control, the phosphopeptide solution is added to wells without kinase (=100% phosphorylation control). The non inhibited kinase reaction will result in a phosphorylation corresponding to 20%-30% of the phosphorylation control.The reaction is performed for 1 h at room temperature before 5 μl of the development solution is added. After a further incubation for 1 h at room temperature 5 μl of the stop reagent is added. The plates are read on a Flex Station II 384 (Molecular Devices).To control for any potential inhibition of the protease present in the development solution, the phosphopeptide is incubated with the development solution in the presence of the highest concentration of the test compound (usually 100 μM or 10 μM).
- HIV Integrase Inhibitory Assay The donor DNA was diluted with TE buffer to 20 nM, of which 50 μL was added to each well of streptavidin-coated black plate (manufactured by PIAS Corporation) and allowed to adsorb at 37° C. for 20 min. The plate was washed with phosphate buffer (Dulbecco's PBS, Sanko Junyaku Co., Ltd.) containing 0.1% Tween 20 and phosphate buffer. Then, an enzyme reaction mixture (70 μL), a test substance (10 μL) diluted with the enzyme reaction mixture and 0.75 μM integrase protein (10 μL) were added to each well and the mixture was reacted at 37° C. for 60 min. composition of enzyme reaction mixture: 30 mM MOPS (3-morpholinopropanesulfonic acid), 5 mM magnesium chloride, 3 mM DTT (dithiothreitol), 0.1 mg/mL BSA (bovine serum albumin), 5% glycerol, 10% DMSO (dimethyl sulfoxide), 0.01% Tween 20.Then, 25 nM target DNA (10 μL) was added, and the mixture was reacted at 37° C. for 20 min and washed with phosphate buffer containing 0.1% Tween 20 to stop the reaction. Then, 100 mU/mL peroxidase labeled anti-digoxigenin antibody solution (Roche, 100 μL) was added, and the mixture was reacted at 37° C. for 60 min, followed by washing with phosphate buffer containing 0.1% Tween 20.Then, peroxidase fluorescence substrate solution (manufactured by PIAS Corporation, 100 μL) was added, and the mixture was reacted at room temperature for 20 min to 30 min. A reaction quenching liquid (manufactured by PIAS Corporation, 100 μL) was added to discontinue the reaction, and fluorescence intensity at excitation wavelength 325 nm/fluorescence wavelength 420 nm was measured.
- HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence. Varying concentrations of inhibitors at 3x the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 ul) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 ul of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 ul in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined um value of 8 uM for the QSY7-APPswe-Eu substrate at BACE1.
- HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3x the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 ul) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 ul of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 ul in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined um value of 8 uM for the QSY7-APPswe-Eu substrate at BACE1.
- HTRF FRET Assay BACE1: A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3× the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 μl) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 μl of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 μl in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined μm value of 8 μM for the QSY7-APPswe-Eu substrate at BACE1.
- IDH2 Enzymatic Assay Compounds were assayed for IDH2 R140Q inhibitory activity through a cofactor depletion assay. Compounds were preincubated with enzyme, then the reaction was started by the addition of NADPH and α-KG, and allowed to proceed for 60 minutes under conditions previously demonstrated to be linear with respect for time for consumption of both cofactor and substrate. The reaction was terminated by the addition of a second enzyme, diaphorase, and a corresponding substrate, resazurin. Diaphorase reduces resazurin to the highly fluorescent resorufin with the concomitant oxidation of NADPH to NADP, both halting the IDH2 reaction by depleting the available cofactor pool and facilitating quantitation of the amount of cofactor remaining after a specific time period through quantitative production of an easily detected fluorophore.Specifically, into each of 12 wells of a 384-well plate, 1 μl of compound dilution series was placed, followed by the addition of 40 μl of buffer (50 mM potassium phosphate, pH 7.5; 150 mM NaCl; 10 mM MgCl2, 10% glycerol, 0.05% bovine serum albumin, 2 mM beta-mercaptoethanol) containing 1.25 μg/ml IDH2 R140Q. The compound was then incubated for one hour at room temperature with the enzyme; before starting the IDH2 reaction with the addition of 10 μl of substrate mix containing 50 μM NADPH and 6.3 mM α-KG in the buffer described above. After a further one hour of incubation at room temperature, the reaction was halted and the remaining NADPH measured through conversion of resazurin to resorufin by the addition of 25 μl Stop Mix (36 μg/ml diaphorase enzyme and 60 μM resazurin; in buffer). After one minute of incubation the plate was read on a plate reader at Ex544/Em590.
- In Vitro Assays for IDH1m (R132H or R132C) Inhibitors A test compound is prepared as 10 mM stock in DMSO and diluted to 50× final concentration in DMSO, for a 50 μl reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutaric acid is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH1-R132 homodimer enzyme is diluted to 0.125 μg/ml in 40 μl of Assay Buffer (150 mM NaCl, 20 mM Tris-Cl pH 7.5, 10 mM MgCl2, 0.05% BSA, 2 mM b-mercaptoethanol); 1 μl of test compound dilution in DMSO is added and the mixture is incubated for 60 minutes at room temperature. The reaction is started with the addition of 10 μl of Substrate Mix (20 μl NADPH, 5 mM alpha-ketoglutarate, in Assay Buffer) and the mixture is incubated for 90 minutes at room temperature. The reaction is terminated with the addition of 25 μl of Detection Buffer (36 μg/ml diaphorase, 30 mM resazurin, in 1× Assay Buffer), and is incubated for 1 minute before reading on a SpectraMax platereader at Ex544/Em590.Compounds are assayed for their activity against IDH1 R132C following the same assay as above with the following modifications: Assay Buffer is (50 mM potassium phosphate, pH 6.5; 40 mM sodium carbonate, 5 mM MgCl2, 10% glycerol, 2 mM b-mercaptoethanol, and 0.03% BSA). The concentration of NADPH and alpha-ketoglutarate in the Substrate Buffer is 20 μM and 1 mM, respectively.
- In Vitro Assays for IDH1m (R132H or R132C) The following describes the experimental procedures that can be used to obtain data on columns 3 and 6 of Table 4.A test compound is prepared as 10 mM stock in DMSO and diluted to 50× final concentration in DMSO, for a 50 μl reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutaric acid is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH1-R132 homodimer enzyme is diluted to 0.125 μg/ml in 40 μl of Assay Buffer (150 mM NaCl, 20 mM Tris-Cl pH 7.5, 10 mM MgCl2, 0.05% BSA, 2 mM b-mercaptoethanol); 1 μl of test compound dilution in DMSO is added and the mixture is incubated for 60 minutes at room temperature. The reaction is started with the addition of 10 μl of Substrate Mix (20 μl NADPH, 5 mM alpha-ketoglutarate, in Assay Buffer) and the mixture is incubated for 90 minutes at room temperature. The reaction is terminated with the addition of 25 μl of Detection Buffer (36 μg/ml diaphorase, 30 mM resazurin, in 1× Assay Buffer), and is incubated for 1 minute before reading on a SpectraMax platereader at Ex544/Em590.Compounds are assayed for their activity against IDH1 R132C following the same assay as above with the following modifications: Assay Buffer is (50 mM potassium phosphate, pH 6.5; 40 mM sodium carbonate, 5 mM MgCl2, 10% glycerol, 2 mM b-mercaptoethanol, and 0.03% BSA). The concentration of NADPH and alpha-ketoglutarate in the Substrate Buffer is 20 μM and 1 mM, respectively.
- In Vitro Assays for IDH2m R140Q Inhibitors Compounds are assayed for IDH2 R140Q inhibitory activity through a cofactor depletion assay. Compounds are preincubated with enzyme and cofactor, then the reaction is started by the addition of α-KG, and allowed to proceed for 60 minutes under conditions previously demonstrated to be linear. The reaction is terminated by the addition of a second enzyme, diaphorase, and a corresponding substrate, resazurin. Diaphorase reduces resazurin to the highly fluorescent resorufin with the concomitant oxidation of NADPH to NADP, both halting the IDH2 reaction by depleting the available cofactor pool and facilitating quantitation of the amount of cofactor remaining after a specific time period through quantitative production of an easily detected fluorophore.Specifically, into each of 12 wells of a 384-well plate, 1 μl of 50× compound dilution series is placed, followed by the addition of 40 μl of buffer (50 mM potassium phosphate (K2HPO4), pH 7.5; 150 mM NaCl; 10 mM MgCl2, 10% glycerol, 0.05% bovine serum albumin, 2 mM beta-mercaptoethanol) containing 0.39 μg/ml IDH2 R140Q protein, 5 uM NADPH and 750 uM NADP. The test compound is then incubated for 16 hrs at room temperature with the enzyme and cofactors before starting the IDH2 reaction with the addition of 10 μl of substrate mix containing 8 mM α-KG (final concentration 1.6 mM) in the buffer described above. After a further 1 hour of incubation at room temperature, the reaction is halted and the remaining NADPH measured through conversion of resazurin to resorufin by the addition of 25 μl Stop Mix (36 μg/ml diaphorase enzyme and 60 μM resazurin; in buffer). After one minute of incubation the plate is read on a plate reader at Ex544/Em590.
- In Vitro Assays for IDH2m R140Q Inhibitors Compounds are assayed for IDH2 R140Q inhibitory activity through a cofactor depletion assay. Compounds are preincubated with enzyme and cofactor, then the reaction is started by the addition of α-KG, and allowed to proceed for 60 minutes under conditions previously demonstrated to be linear. The reaction is terminated by the addition of a second enzyme, diaphorase, and a corresponding substrate, resazurin. Diaphorase reduces resazurin to the highly fluorescent resorufin with the concomitant oxidation of NADPH to NADP, both halting the IDH2 reaction by depleting the available cofactor pool and facilitating quantitation of the amount of cofactor remaining after a specific time period through quantitative production of an easily detected fluorophore.Specifically, into each of 12 wells of a 384-well plate, 1 μl of 50× compound dilution series is placed, followed by the addition of 40 μl of buffer (50 mM potassium phosphate (K2HPO4), pH 7.5; 150 mM NaCl; 10 mM MgCl2, 10% glycerol, 0.05% bovine serum albumin, 2 mM beta-mercaptoethanol) containing 0.39 μg/ml IDH2 R140Q protein, 5 uM NADPH and 750 uM NADP. The test compound is then incubated for 16 hrs at room temperature with the enzyme and cofactors before starting the IDH2 reaction with the addition of 10 μl of substrate mix containing 8 mM α-KG (final concentration 1.6 mM) in the buffer described above. After a further 1 hour of incubation at room temperature, the reaction is halted and the remaining NADPH measured through conversion of resazurin to resorufin by the addition of 25 al Stop Mix (36 g/ml diaphorase enzyme and 60 μM resazurin; in buffer). After one minute of incubation the plate is read on a plate reader at Ex544/Em590.
- In Vitro Enzyme Activity Assay The full-length coding sequences of human TPH1 and TPH2 were PCR amplified, ligated into a MBP fusion vector (pMalc2x, New England Biolabs, MA, USA) and transformed into SCS1 (Stratagene, CA, USA) to amplify plasmid DNA. For the overexpression of TPH proteins, the constructs were transformed into Rosetta (DE3) (Novagen®/EMD Millipore, Mass., USA) and cultivated in terrific broth (TB) medium (AppliChem, Darmstadt, Germany) at 37° C. When the bacterial cultures reached an OD600≈2, expression was induced with 0.5 mM IPTG (AppliChem, Darmstadt, Germany) over night at 17° C. The purification of soluble proteins started with sonication-mediated cell disruption in lysis buffer (1×PBS pH 7.4, 0.5 M NaCl, 5% Glycerol+CHAPS, DTT, PMSF, benzonase), followed by affinity purification (MBPTrap, GE Healthcare, UK) and gel filtration (26/60 Superdex 200 prep grade, GE Healthcare, UK), according to the manufacturer's protocol. The quality of protein expression and solubility was controlled by SDS-PAGE and Coomassie blue staining.The enzymatic reaction was carried out in black 96-well flat bottom plates (Corning GmbH, Wiesbaden). TPH1 and TPH2 activities were measured in a reaction mixture containing 50 mM 4-Morpholineethanesulfonic acid (MES), pH 7.0, 40 μM tryptophan, 200 mM ammonium sulfate, 25 μM ferrous ammonium sulfate, 50 μM tetrahydrobiopterin, 25 μg/ml catalase, and 7 mM DTT. The reactions were initiated by adding TPH1 or TPH2 to a final concentration of 5 μg/ml. Initial velocity of the reactions was determined by following the change of fluorescence at 330 nm (excitation wavelength=300 nm) (Infinite M200, Tecan, Crailsheim).
- LXR alpha/beta Radioligand Binding Assay Compounds of the invention were assessed in a competition binding assay where different concentrations of compounds were incubated with the LXR ligand binding domain (LBD) in the presence of radiolabeled LXR ligand [3H]TO901317. The amount of the LXR-LBD that complexed with [3H]T0901317 was measured by scintillation proximity assay (SPA) employing non-specific binding of LXR-LBD to poly-lysine coated Yttrium silicate beads. Partially purified LXR α or β LBD protein (15-45 nM) was incubated at rt for 30 min with 15 nM [3H]TO901317 (25-40 Ci/mmol) and different concentrations of test compounds in 80 μL of phosphate buffered saline (PBS) buffer containing 2.5% DMSO, 1% glycerol, 2 mM EDTA, 2 mM CHAPS and 5 mM DTT in 96-well plates. Poly-lysine SPA beads (50 μg) were added to each well and the total volume was adjusted to 120 μL. The plates were shaken on an orbital shaker for 20 min and then allowed to settle for 10 more min at rt before a brief centrifugation at 2,000 rpm for 1 min. The SPA signal was measured on a MicroBeta® liquid scintillation counter (Perkin Elmer, Waltham, Mass.), and the results were used for calculating IC50 values based on the total binding (DMSO control) and non-specific binding (5 μM of unlabeled TO901317) controls. The Ki values were calculated according to equation 1, where [RL] is the final concentration of [3H]TO901317 in the assay, and the Kd values of 20 nM and 10 nM of TO901317 for LBDs of LXRα and LXRβ, respectively, were determined by direct titration of the radioligand with these proteins.
- Omnia Assay A 10× stock solution of FGFR4-WT (PR4380C), (from Invitrogen, Carlsbad, Calif.) corresponding to method a in Table 7, was prepared as described below. Alternatively, a 10× stock solution of FGFR4-WT (F01-11G), (SignalChem, Richmond, BC) corresponding to method b in Table 7, was prepared as described below. A solution of 1.4×ATP (AS001A) and 5×Tyr-Sox conjugated peptide substrate (KNZ3101) were prepared in IX kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of FGFR4 was pipetted into a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.), containing a 0.5 μL volume of 100% DMSO. The serially diluted compounds were prepared on a Tecan EVO100. A second addition of 10 μl of Tyr-Sox FGFR4 substrate was added to each well and the kinase reactions were started with the addition of 35 μL of 1.4×ATP. The reactions were monitored every 71 seconds for 240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to 60 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (seconds) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response (Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.)).
- Omnia Assay Protocol for Potency Assessment Against EGFR (WT) and EGFR (T790M/L858R) Active Enzymes Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).
- Omnia Assay The protocol below describes continuous-read kinase assays to measure potency of compounds against activated ERK1 enzyme. The mechanics of the assay platform are best described by the vendor (Invitrogen, Carlsbad, Calif.) on their website at the following URL: invitrogen.com/site/us/en/home.html.Briefly, a 1.25× stock of ERK1 enzyme (14-439-K) from Millipore (Billerica, Mass.), 5×ATP (AS001A) and ST17-Sox conjugated peptide substrate (KNZ1171C) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT. 10 μL of ATP/ST17-sox peptide substrate mix was combined with 0.5 μL volume of 100% DMSO and serially diluted compounds were prepared in 100% DMSO in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.). Kinase reactions were started with the addition of 40 μL of ERK1 solution and monitored every 71 seconds for 30-240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜30+ minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes or seconds) and then plotted against inhibitor concentration to estimate AppIC50 from log [Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).
- Q13822 Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Radio-Ligand Binding Assay Compounds described herein were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. # T2320).
- Time-Resolved Endpoint Proteolysis Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3x the desired final concentration in 1ÿBACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1xBACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1xBACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 us delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50s are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s are obtained when using raw RFU data. The Ki values are calculated from the IC50 using the Cheng-Prusoff equation.
- Time-Resolved Endpoint proteolysis Assay Inhibitor IC50's at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3x the desired final concentration in 1xBACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1xBACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1xBACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 us delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50s are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s are obtained when using raw RFU data. The Ki values are calculated from the IC50 using the Cheng-Prusoff equation.
- a time-resolved fluorescence resonance energy transfer (TR-FRET) assay Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2×Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 pM, and PI3Kγ at 2 nM. The compounds of Table 1 and Compound X, ((S)-2,4-diamino-6-((1-(5-chloro-4-oxo-3-phenyl-3,4-dihydroquinazolin-2-yl)ethyl)amino)pyrimidine-5-carbonitrile) were added to the assay solution and incubated for 30 minutes at 25° C. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 μs delay and 500 μs read window).The results were normalized based on positive (1 pM wortmanin) and negative (DMSO) controls, and the IC50 values for PI3K α, β, δ, and γ were calculated from the fit of the dose-response curves to a four-parameter equation. These assays generally produced results within 3-fold of the reported mean.
- kinetic binding analysis Dual histidine and Avi tagged human EIF4E (His6-3C-avi-eIF4E) was expressed in 8 L of TB Media. Induction by 0.4 mM IPTG occurred at 2.0 OD600, and cells were harvested at 15 OD600. 225 gram pellet was diluted in buffer (50 mM Tris, 500 mM NaCl, 2 mM MgCl2, 1 mM TCEP, pH 7.5 containing 10% glycerol, protease inhibitors, and DNase) to volume of 600 mL and passed once over the microfluidizer. Sample was run on 5 mL HisTrap HP IMAC at 4.0 mL/min IMAC with a 25 mM to 500 mM imidazole gradient for one column volume. GST-PreScission Protease (2 mg, made in-house) was added to sample and allowed to react overnight at 4° C. The cleaved pool was passed over 0.5 mL GST and 0.5 IMAC resin in a gravity column. Sample volume was increased to 800 mL using 50 mM Tris pH 7.5, 1 mM TCEP and passed over a 5 mL hiTrap SP FF at 4.0 mL/min with a 0 to 1 M NaCl gradient over 20 column volumes. Sample was then injected onto a 124 mL S75 Gel Filtration Column at 20 mg/mL. Final Avi-eIF4E (26931 Da) was diluted to 1 mg/mL in 1× Bicine buffer to a volume of 2.5 mg and mixed with ATP/Biotin Mix (10 mM ATP, 10 mM Mg(OAc)2, 50 μM d-biotin final). Biotin Ligase (25 μg BirA produced in house) was added to reaction. Reactions were performed with mixing (500 rpm) on Eppendorf ThermoMixer R at 30° C. for 60 minutes and checked for completeness using LC-MS. To the sample, 100 μl of immobilized glutathione (1:1 with buffer) was add and mixed for 15 min at 4° C. to bind C3 and Bir3 and removed by centrifugation. The sample was buffer exchanged using two consecutive PD-10 columns equilibrated with 20 mM HEPES, 100 mM KCl, 1 mM DTT, pH 7.5.Due to low eIF4E stability, the streptavidin coated chip was prepared and run at 10° C. on the Biacore T200. The eIF4E (0.04 mg/mL, 150 μl) was bound to the sample channel of Series S Sensor Chip SA (GE Life Sciences, BR-1005-31) to surface density of 5000 to 7000 RU (Response Units). Buffer flowed over the chip at 30 μL/min, using 1×PBS, 50 mM NaCl, 0.1% Glycerol, 0.1% CHAPS, and 1% DMSO. Samples of various cap analogs were diluted to various concentrations in a range of 100 μM to less than 1 nM. Samples were injected into the Biacore chip with a two minute association time and a five minute dissociation time. Several buffer injections were done for each sample for blank subtraction.Analysis was done for all sets using Biacore T200 evaluation software. Binding analysis for all compounds is reported as response units at 1 micromolar compound where a higher value for RU is interpreted as greater ligand binding to the surface immobilized eIF4E protein. A subset of compounds was further characterized to determine dissociation constants using kinetic binding. Steady State Affinity fits were done with default settings (4 seconds before injection stop with 5 second window). Kinetic fits were normally done with 1:1 binding model, with constant RI=0 and all other variables set to fit globally.
- Assay of Inhibition of Escherichia coli RNA Polymerase Fluorescence-detected RNA polymerase assays with E. coli RNA polymerase were performed by a modification of the procedure of Kuhlman et al., 2004 [Kuhlman, P., Duff, H. & Galant, A. (2004) A fluorescence-based assay for multisubunit DNA-dependent RNA polymerases. Anal. Biochem. 324, 183-190]. Reaction mixtures contained (20 μl): 0-100 nM test compound, 75 nM E. coli RNA polymerase σ70 holoenzyme, 20 nM 384 bp DNA fragment containing the bacteriophage T4 N25 promoter, 100 μM ATP, 100 μM GTP, 100 μM UTP, 100 μM CTP, 50 mM Tris-HCl, pH 8.0, 100 mM KCl, 10 mM MgCl2, 1 mM DTT, 10 μg/ml bovine serum albumin, and 5.5% glycerol. Reaction components other than DNA and NTPs were pre-incubated for 10 min at 37° C. Reactions were carried out by addition of DNA and incubation for 5 min at 37° C., followed by addition of NTPs and incubation for 60 min at 37° C. DNA was removed by addition of 1 μl 5 mM CaCl2 and 2 U DNaseI (Ambion, Inc.), followed by incubation for 90 min at 37° C. RNA was quantified by addition of 100 μl RiboGreen RNA Quantitation Reagent (Invitrogen, Inc.; 1:500 dilution in Tris-HCl, pH 8.0, 1 mM EDTA), followed by incubation for 10 min at 25° C., followed by measurement of fluorescence intensity [excitation wavelength=485 nm and emission wavelength=535 nm; QuantaMaster QM1 spectrofluorometer (PTI, Inc.)]. IC50 is defined as the concentration of inhibitor resulting in 50% inhibition of RNA polymerase activity.
- BACE1 HTRF FRET Assay A homogeneous time-resolved FRET assay can be used to determine IC50 values for inhibitors of the soluble human BACE1 catalytic domain. This assay monitors the increase of 620 nm fluorescence that resulted from BACE1 cleavage of an APPswedish APPswe mutant peptide FRET substrate (QSY7-EISEVNLDAEFC-Europium-amide). This substrate contains an N-terminal QSY7 moiety that serves as a quencher of the C-terminal Europium fluorophore (620 nm Em). In the absence of enzyme activity, 620 nm fluorescence is low in the assay and increased linearly over 3 hours in the presence of uninhibited BACE1 enzyme. Inhibition of BACE1 cleavage of the QSY7-APPswe-Eu substrate by inhibitors is manifested as a suppression of 620 nm fluorescence.Varying concentrations of inhibitors at 3ÿ the final desired concentration in a volume of 10 ul are preincubated with purified human BACE1 catalytic domain (3 nM in 10 ul) for 30 minutes at 30° C. in reaction buffer containing 20 mM Na-Acetate pH 5.0, 10% glycerol, 0.1% Brij-35 and 7.5% DSMO. Reactions are initiated by addition of 10 ul of 600 nM QSY7-APPswe-Eu substrate (200 nM final) to give a final reaction volume of 30 ul in a 384 well Nunc HTRF plate. The reactions are incubated at 30° C. for 1.5 hours. The 620 nm fluorescence is then read on a Rubystar HTRF plate reader (BMG Labtechnologies) using a 50 millisecond delay followed by a 400 millisecond acquisition time window. Inhibitor IC50 values are derived from non-linear regression analysis of concentration response curves. Ki values are then calculated from IC50 values using the Cheng-Prusoff equation using a previously determined um value of 8 uM for the QSY7-APPswe-Eu substrate at BACE1. The compounds of Examples 1, 2, and 3 were measured in this assay and each exhibited a Ki value of less than about 5 nM.
- Binding Assay Compounds described herein were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. #NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. #RPNQ0010) were added to achieve 50 ag of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. #T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves.
- Binding Assay Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. #NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. #RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. #T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves.
- Binding Assay Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy[26,27-3H]-cholesterol (PerkinElmer, Cat. #NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy[26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. #RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. #T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves.
- Biochemical Assay The mechanics of the assay platform are best described by the vendor (Invitrogen, Carlsbad, Calif.) on their web site at the following URL: www.invitrogen.com/content.cfm?pageid=11338 or www.invitrogen.com/site/us/en/home/Products-and-Services/Applications/Drug-Discovery/Target-and-Lead-Identification-and-Validation/KinaseBiology/KB-Misc/Biochemical-Assays/Omnia-Kinase-Assays.html.Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to 30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).
- Biological Assay Receptor competition binding assays are run in a buffer made up of DPBS (1 L) (Hyclone #SH30028.03), 2.2 g BSA Fraction v (Roche #9048-46-8), 100 mL glycerol (Fischer #56-81-5) and 40 mL DMSO (reagent grade). The final wells contain 20 μg/mL aprotinin and 20 μg/mL leupeptin and 10 μM Pefabloc. Typically, receptor binding assays include radio-labeled ligands, such as 7 nM [3H]-25-hydroxycholesterol for alpha binding, 20 nM [3H]-3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for beta binding, and 6 nM [3H]-25-hydroxycholesterol for gamma binding, and 0.5 μg RORa receptor, 0.03 μg RORb receptor, or 0.13 μg RORg receptor per well. Assays are typically run in 96-well format. Competing test compounds are added at various concentrations ranging from about 0.4 nM to 25 μM. Non-specific binding is determined in the presence of 250 nM 25-hydroxycholesterol for RORa and RORg binding, 250 nM 3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for RORb binding. The sample, label and receptor solutions are combined in a 96 well assay plate (Costar 3632) and incubated overnight at room temperature, then 25 μl beads (Amersham YSi (2-5 micron) copper His-tag Spa Beads, #RPNQ0096) for a final bead concentration of 1 mg/well is added to each reaction. Plates are mixed for 30 minutes on an orbital shaker at room temperature. After an incubation of 4 hours, plates are read in a Wallac MICROBETA® counter.
- FRET Activity Assay Expression and purification of the FXR-LBD: An overnight preculture of a transformed E. coli strain was diluted 1:20 in LB-Ampicillin medium and grown at 30° C. to an optical density of OD600=0.4-0.6. Gene expression was then induced by addition of 0.5 mM IPTG. Cells were incubated an additional 6 h at 30° C., 180 rpm. Cells were collected by centrifugation (7000×g, 7 min, rt). Per liter of original cell culture, cells were resuspended in 10 mL lysis buffer (50 mM Glucose, 50 mM Tris pH 7.9, 1 mM EDTA and 4 mg/mL lysozyme) and left on ice for 30 min. Cells were then subjected to sonication and cell debris removed via centrifugation (22000×g, 30 min, 4° C.). Per 10 mL of supernatant 0.5 mL prewashed Glutathione 4B sepharose slurry (Qiagen) was added and the suspension kept slowly rotating for 1 h at 4° C. Glutathione 4B sepharose beads were pelleted by centrifugation (2000×g, 15 sec, 4° C.) and washed twice in wash buffer (25 mM Tris, 50 mM KCl, 4 mM MgCl2 and 1M NaCl). The pellet was resuspended in 3 mL elution buffer per liter of original culture (elution buffer: 20 mM Tris, 60 mM KCl, 5 mM MgCl2 and 80 mM glutathione added immediately prior to use as powder). The suspension was left rotating for 15 min at 4° C., the beads pelleted and eluted again with half the volume of elution buffer than the first time. The eluates were pooled and dialysed overnight in 20 mM Hepes buffer (pH 7.5) containing 60 mM KCl, 5 mM MgCl2 as well as 1 mM dithiothreitol and 10% (v/v) glycerol. The protein was analysed by SDS-Page.
- HCT116 FOPFlash In preparation of the assay, the two cell lines were plated 24 hours before at 10000 cells per well of a 384 micro titre plate (MTP) in 30 μL growth medium. Selective inhibitory activity for small molecules on the mutated Wnt pathway was determined after parallel incubation of both (TOP and FOP) HCT116 reporter cell lines with a compound dilution series from 50 μM to 15 nM in steps of 3.16-fold dilutions in CAFTY buffer (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 5 mM NaHCO3, pH 7.4) containing 2 mM Ca2+ and 0.01% BSA. The compounds were thereby serially prediluted in 100% DMSO and thereafter in addition 50 fold into the CAFTY compound dilution buffer (described above). From this dilution 10 μL were added to the cells in 30 μL growth medium and incubated for 36 hours at 37° C. and 5% CO2. Thereafter luciferase assay buffer (1:1 mixture of luciferase substrate buffer (20 mM Tricine, 2.67 mM MgSO4, 0.1 mM EDTA, 4 mM DTT, 270 μM Coenzyme A, 470 μM Luciferin, 530 μM ATP, ph adjusted to pH 7.8 with a sufficient volume of 5M NaOH) and Triton buffer (30 mL Triton X-100, 115 mL glycerol, 308 mg Dithiothreitol, 4.45 g Na2HPO4.2H2O, 3.03 g TRIS HCl, ad 1I H2O, pH 7.8) was added as equal volume to the compound solution on the cells to determine luciferase expression as a measure of Wnt signaling activity in a luminometer.n order to determine the inhibitory activity of compounds for the WT Wnt signaling pathway, the Super FopFlash vector were cotransfected with pcDNA3 into HEK293 cells.
- HCT116 TOPFlash Assay In preparation of the assay, the two cell lines were plated 24 hours before at 10000 cells per well of a 384 micro titre plate (MTP) in 30 μL growth medium. Selective inhibitory activity for small molecules on the mutated Wnt pathway was determined after parallel incubation of both (TOP and FOP) HCT116 reporter cell lines with a compound dilution series from 50 μM to 15 nM in steps of 3.16-fold dilutions in CAFTY buffer (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 5 mM NaHCO3, pH 7.4) containing 2 mM Ca2+ and 0.01% BSA. The compounds were thereby serially prediluted in 100% DMSO and thereafter in addition 50 fold into the CAFTY compound dilution buffer (described above). From this dilution 10 μL were added to the cells in 30 μL growth medium and incubated for 36 hours at 37° C. and 5% CO2. Thereafter luciferase assay buffer (1:1 mixture of luciferase substrate buffer (20 mM Tricine, 2.67 mM MgSO4, 0.1 mM EDTA, 4 mM DTT, 270 μM Coenzyme A, 470 μM Luciferin, 530 μM ATP, ph adjusted to pH 7.8 with a sufficient volume of 5M NaOH) and Triton buffer (30 mL Triton X-100, 115 mL glycerol, 308 mg Dithiothreitol, 4.45 g Na2HPO4.2H2O, 3.03 g TRIS HCl, ad 1I H2O, pH 7.8) was added as equal volume to the compound solution on the cells to determine luciferase expression as a measure of Wnt signaling activity in a luminometer.n order to determine the inhibitory activity of compounds for the WT Wnt signaling pathway, the Super TopFlash vector were cotransfected with pcDNA3 into HEK293 cells.
- HCV RdRp assays HCV NS5B RdRp Enzyme Assay. An on-bead solid phase homogeneous assay was used in a 384-well format to assess NS5B inhibitors (WangY-K, Rigat K, Roberts S, and Gao M (2006) Anal Biochem, 359: 106-111). The biotinylated oligo dT12 primer was captured on streptavidin-coupled imaging beads (GE, RPNQ0261) by mixing primer and beads in 1× buffer and incubating at room temperature for three hours. Unbound primer was removed after centrifugation. The primer-bound beads were resuspended in 3× reaction mix (20 mM Hepes buffer, pH 7.5, dT primer coupled beads, poly A template, 3H-UTP, and RNAse inhibitor (Promega N2515)). Compounds were serially diluted 1:3 in DMSO and aliquoted into assay plates. Equal volumes (5 μL) of water, 3× reaction mix, and enzyme in 3× assay buffer (60 mM Hepes buffer, pH 7.5, 7.5 mM MgCl2, 7.5 mM KCl, 3 mM DTT, 0.03 mg/mL BSA, 6% glycerol) were added to the diluted compound on the assay plate. Final concentration of components in 384-well assay: 0.36 nM template, 15 nM primer, 0.29 μM 3H-UTP (0.3 μCi), 1.6 U/μL RNAse inhibitor, 7 nM NS5B enzyme, 0.01 mg/mL BSA, 1 mM DTT, and 0.33 μg/μL beads, 20 mM Hepes buffer, pH 7.5, 2.5 mM MgCl2, 2.5 mM KCl, and 0.1% DMSO.Reactions were allowed to proceed for 24 hours at 30° C. and terminated by the addition of 50 mM EDTA (5 μL). After incubating for at least 15 minutes, plates were read on an Amersham LEADseeker multimodality imaging system.
- In Vitro Assay For determination of IC50 values, the reactions were carried out in 384-well white Polyplates (Perkin Elmer) in a total volume of 20 μL. To 1 μL of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 μL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 15 minutes. hDGAT2 membrane fractions were diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical; dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock). 10 μL of this enzyme working solution was added to the plates and incubation continued for 2 hours at room temperature. DGAT2 reactions were initiated by the addition of 4 μL of substrates containing 30 μM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 μM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 μL of 1% H3PO4. After the addition of 45 μL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.). Plates were centrifuged at 2,000×g for 1 minute in an Allegra 6R Centrifuge (Beckman Coulter) and then were sealed again with fresh covers before reading in a 1450 Microbeta Wallac Trilux Scintillation Counter (Perkin Elmer).
- In Vitro Assay For determination of IC50 values, the reactions were carried out in 384-well white polypropylene plates (Nunc) in a total volume of 20 μL. To 1 μL of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 μL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 15 minutes. hDGAT2 membrane fractions were diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical, dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock). 10 μL of this enzyme working solution was added to the plates and incubation continued for 2 hours at room temperature. DGAT2 reactions were initiated by the addition of 4 μL of substrates containing 30 μM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 μM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 μL of 1% H3PO4. After the addition of 45 μL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.). Plates were centrifuged at 2,000×g for 1 minute in an Allegra 6R Centrifuge (Beckman Coulter) and then were sealed again with fresh covers before reading in a 1450 Microbeta Wallac Trilux Scintillation Counter (Perkin Elmer). DGAT2 activity was measured by quantifying the generated product [14C]tridecanoylglycerol in the upper organic phase.
- In Vitro Assays for IDH1m (R132H or R132C) Inhibitors A test compound is prepared as 10 mM stock in DMSO and diluted to 50× final concentration in DMSO, for a 50 μl reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutaric acid is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH1-R132H homodimer enzyme is diluted to 0.125 μg/ml in 40 μl of Assay Buffer (150 mM NaCl, 20 mM Tris-Cl pH 7.5, 10 mM MgCl2, 0.05% BSA, 2 mM b-mercaptoethanol) containing 5 μM NADPH and 37.5 μM NADP; 1 μl of test compound dilution in DMSO is added and the mixture is incubated for 60 minutes at room temperature. The reaction is started with the addition of 10 μl of Substrate Mix (20 μl NADPH, 5 mM alpha-ketoglutarate, in Assay Buffer) and the mixture is incubated for 60 minutes at room temperature. The reaction is terminated with the addition of 25 μl of Detection Buffer (36 μg/ml diaphorase, 30 mM resazurin, in 1× Assay Buffer), and is incubated for 1 minute before reading on a SpectraMax platereader at Ex544/Em590.Compounds are assayed for their activity against IDH1 R132C following the same assay as above with the following modifications: IDH1-R132C homodimer enzyme is diluted to 0.1875 μg/ml in 40 μl of Assay Buffer (50 mM potassium phosphate, pH 6.5; 40 mM sodium carbonate, 5 mM MgCl2, 10% glycerol, 2 mM b-mercaptoethanol, and 0.03% BSA) containing 5 uM NADPH and 28.75 uM NADP. The concentration of alpha-ketoglutarate in the Substrate Buffer is 1 mM.
- In Vitro DGAT2 Assay For determination of IC50 values, the reactions were carried out in 384-well white Polyplates (Perkin Elmer) in a total volume of 20 uL. To 1 uL of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 uL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 20 minutes. To this mixture, 10 uL of hDGAT2 membrane fraction (0.01 mg/mL) diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical; dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock) was added. After this mixture was preincubated at room temperature for 2 hours, DGAT2 reactions were initiated by the addition of 4 uL of substrates containing 30 uM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 uM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 uL of 1% H3PO4. After the addition of 45 uL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.). Plates were centrifuged at 2,000×g for 1 min in an Allegra 6R Centrifuge (Beckman Coulter) and then were sealed again with fresh covers before reading in a 1450 Microbeta Wallac Trilux Scintillation Counter (Perkin Elmer). DGAT2 activity was measured by quantifying the generated product [14C]tridecanoylglycerol in the upper organic phase.
- In Vitro Inhibition of DAGL Briefly, membrane proteome (1 mg/ml, 20 μL) was prepared from HEK293T cells (transiently transfected with hDAGLα-FLAG or hDAGLα-S472A-FLAG, hDAGLβ-FLAG or hDAGLβ-S443A-FLAG) as described in Example 16. The proteome was incubated at room temperature with vehicle (DMSO) or compound in 0.5 μL DMSO for 30 min. The membrane proteome sample was subsequently treated for 30 min with HT-01 probe (1 μM) or FP-Rh probe (1 μM). The reactions were quenched with 10 μL 3× Laemmli sample buffer (final concentrations: 60 mM Tris-Cl pH 6.8, 2% (w/v) SDS, 10% (v/v) glycerol, 5% (v/v) (3-mercaptoethanol, 0.01% (v/v) bromophenol blue). The samples were directly loaded and resolved on SDS page gel (10% acrylamide). The gels were scanned using a ChemiDoc MP system (Cy3 settings, 605/50 filter).The resolved proteins were transferred from the gels to a polyvinyldifluoride membrane for Western Blotting using a Trans-Blot® Turbo (BioRad). FLAG-tagged enzymes were stained using rabbit anti-FLAG as primary antibody, and goat-anti-rabbit HRP as secondary antibody. The blot was developed in the dark using a 10 mL luminal solution, 100 μL ECL enhancer and 3 μL H2O2. Chemiluminescence was visualized using a ChemiDoc XRS (BioRad).The percentage of DAGL activity remaining in the assayed samples was determined by measuring the integrated optical intensity of the fluorescent protein bands of the Western Blot using image lab 4.1. The relative intensity was compared to the vehicle (DMSO) treated proteins, which were set to 100%. IC50 values were determined by plotting a log(inhibitor) vs. normalized response (Variable slope) dose-response curve generated using Prism software (GraphPad).
- Inhibition Assay The assay is a capture of radioactive 33P phosphorylated product through filtration. The interactions of Btk, biotinylated SH2 peptide substrate (Src homology), and ATP lead to phosphorylation of the peptide substrate. Biotinylated product is bound streptavidin sepharose beads. All bound, radiolabeled products are detected by scintillation counter.Plates assayed are 96-well polypropylene (Greiner) and 96-well 1.2 μm hydrophilic PVDF filter plates (Millipore). Concentrations reported here are final assay concentrations: 10-100 μM compounds in DMSO (Burdick and Jackson), 5-10 nM Btk enzyme (His-tagged, full-length), 30 μM peptide substrate (Biotin-Aca-AAAEEIYGEI-NH2), 100 μM ATP (Sigma), 8 mM imidazole (Sigma, pH 7.2), 8 mM glycerol-2-phosphate (Sigma), 200 μM EGTA (Roche Diagnostics), 1 mM MnCl2 (Sigma), 20 mM MgCl2 (Sigma), 0.1 mg/ml BSA (Sigma), 2 mM DTT (Sigma), 1 μCi 33P ATP (Amersham), 20% streptavidin sepharose beads (Amersham), 50 mM EDTA (Gibco), 2 M NaCl (Gibco), 2 M NaCl w/1% phosphoric acid (Gibco), microscint-20 (Perkin Elmer).IC50 determinations are calculated from 10 data points per compound utilizing data produced from a standard 96-well plate assay template. One control compound and seven unknown inhibitors were tested on each plate and each plate was run twice. Typically, compounds were diluted in half-log starting at 100 μM and ending at 3 nM. The control compound was staurosporine. Background was counted in the absence of peptide substrate. Total activity was determined in the presence of peptide substrate. The following protocol was used to determine Btk inhibition.
- Inhibition Assay The assay is a capture of radioactive 33P phosphorylated product through filtration. The interactions of Btk, biotinylated SH2 peptide substrate (Src homology), and ATP lead to phosphorylation of the peptide substrate. Biotinylated product is bound streptavidin sepharose beads. All bound, radiolabeled products are detected by scintillation counter.Plates assayed are 96-well polypropylene (Greiner) and 96-well 1.2 μm hydrophilic PVDF filter plates (Millipore). Concentrations reported here are final assay concentrations: 10-100 μM compounds in DMSO (Burdick and Jackson), 5-10 nM Btk enzyme (His-tagged, full-length), 30 μM peptide substrate (Biotin-Aca-AAAEEIYGEI-NH2), 100 μM ATP (Sigma), 8 mM imidazole (Sigma, pH 7.2), 8 mM glycerol-2-phosphate (Sigma), 200 μM EGTA (Roche Diagnostics), 1 mM MnCl2 (Sigma), 20 mM mgCl2 (Sigma), 0.1 mg/mL BSA (Sigma), 2 mM DTT (Sigma), 1 μCi 33P ATP (Amersham), 20% streptavidin sepharose beads (Amersham), 50 mM EDTA (Gibco), 2 M NaCl (Gibco), 2 M NaCl w/1% phosphoric acid (Gibco), microscint-20 (Perkin Elmer).IC50 determinations are calculated from 10 data points per compound utilizing data produced from a standard 96-well plate assay template. One control compound and seven unknown inhibitors were tested on each plate and each plate was run twice. Typically, compounds were diluted in half-log starting at 100 μM and ending at 3 nM. The control compound was staurosporine. Background was counted in the absence of peptide substrate. Total activity was determined in the presence of peptide substrate. The following protocol was used to determine Btk inhibition.
- Omnia Assay Briefly, a 1.25× stock of MK-2 enzyme from Invitrogen (PV3317), a 5× stock of ATP (AS001A), and ST3-Sox peptide substrate (KNZ1031C) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT. Compound potency assays were initiated by adding a 0.5 μL volume of 100% DMSO and serially diluted compounds prepared in 100% DMSO to a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) followed immediately by 10 μL of the ST3-Sox peptide and ATP substrate solution. Kinase reactions were started with the addition of 40 μL of MK-2 enzyme and monitored every 71 seconds for 30-240 minutes at λex360/λem485 in a Synergy2, Synergy4 or Synergy H4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to +30 minutes) from each reaction was estimated from the slope of a plot of relative fluorescence units vs time (minutes) and normalized to the no enzyme and no inhibitor control groups for % Inhibition. The resulting % Inhibition values were then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.). Potency results for the compounds tested are shown in Table A in the column entitled “MK2 IC50.”[Reagent] used:[MK-2]=0.4 nM, [ATP]=1.0 mM and [ST3-Sox]=10 μM (ATP appKM=8-10 μM)
- Omnia Assay Protocol for Potency Assessment Against FGFR 4 Enzyme A 10× stock solution of FGFR4-WT (PR4380C or P3054), (from Invitrogen, Carlsbad, Calif.) corresponding to method a in Table 10, was prepared as described below. Alternatively, a 10× stock solution of FGFR4-WT (F01-11G), (SignalChem, Richmond, BC) corresponding to method b in Table 10, was prepared as described below. A solution of 1.4×ATP (AS001A) and 5× Tyr-Sox conjugated peptide substrate (KNZ3101) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM P3-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of FGFR4 was pipetted into a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.), containing a 0.5 μL volume of 100% DMSO. The serially diluted compounds were prepared on a Tecan EVO100. A second addition of 10 μl of Tyr-Sox FGFR4 substrate was added to each well and the kinase reactions were started with the addition of 35 μL of 1.4×ATP. The reactions were monitored every 71 seconds for 240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to −60 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (seconds) and then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response (Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.)).
- RNAP-Inhibition Assay Fluorescence-detected RNAP inhibition assays in Tables 1 and 4 were performed using a DNA fragment containing the lacUV5 promoter as a template and the profluorescent ATP analog γ-[2′-(2-benzothiazoyl)-6′-hydroxybenzothiazole]-ATP(BBT-ATP, Jena Biosciences) as a substrate (methods as in ref 32). Fluorescence-detected RNAP inhibition assays in Figure 2C were performed essentially as described in refs 33 and 34. The assay used a proprietary circular single-stranded DNA as a template (Kool NC-45 Universal RNAP Template, Epicenter). The synthesized RNA was quantified using RiboGreen (ThermoFisher), which exhibits fluorescence enhancement upon binding to RNA. A volume of 0.2 μL of MRL-436 or Rif [10 concentrations from a 3-fold serial dilution in 100% DMSO (v/v)] was loaded into a 384-well plate using an Echo liquid handler (Labcyte). A total of 5 μL of 20 nM recombinant RNAP in assay buffer [50 mM HEPES (pH = 8.0), 50 mM KCl, 4 mM MgCl2, 5% glycerol (v/v), 1 mM DTT, 0.1 mg mL−1 BSA, and 0.01% Triton X-100 (v/v)] was then added. After a 30 min incubation at RT, 5 μL of assay buffer solution containing 0.04 ng/μL DNA template and rNTPs (ATP, CTP, GTP, UTP; 600 μM each; Lucigen) was added to start the reaction. After incubation for 2 h at 37 °C, 70 μL of Quant-iT RiboGreen RNA Reagent [1:350 dilution in buffer containing 10 mM Tris-HCl (pH = 7.5) and 1 mM EDTA] was added to stop the reaction and develop the signal. The plate was read using a PheraStar Plus plate reader (BMG).
- Radio-Ligand RORγ Binding Assay Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. #NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]— cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. #RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. #T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves.
- Radioligand Binding Assay Radioligand binding assays were carried out using commercial or in-house prepared hMC1R, hMC3R and hMC4R membranes and [125I] NDP-MSH, as per the hMC5R procedure in Example 102. In-house plasma membranes were prepared from transfected mammalian cells (prepared as in Example 109, using plasmid DNA containing the human MC1R, MC3R or MC4R gene or other gene of interest in a plasmid vector with a mammalian origin of replication): Adherent cells were washed with warm Hanks buffered saline solution (HBSS). 1 mL of cold HBSS was added to each flask and the cells were scraped off with a rubber policeman. The scraped cells were added to a 50 mL tube on ice. The plates were then rinsed twice with 5 mL cold HBSS and this was also added to the tube. The cells were centrifuged at 1000×g for 5 mins in a bench top centrifuge and the supernatant was decanted. The remaining cell pellet was resuspended in 0.25 M sucrose. The cell suspension was centrifuged again as previously and the pellet resuspended in 5 mL of 0.25 M sucrose containing protease inhibitors. The cells were homogenised by a 10 second pulse with an Ika disperser followed by 30 seconds on ice. The homogenisation and ice incubation was repeated three times. The mixture was then centrifuged at 1260×g for 5 mins. The supernatant was decanted into another centrifuge tube, to which a buffer containing 50 mM Tris, pH 7.4, 12.5 mM MgCl2, 5 mM EGTA and protease inhibitors was added to make the volume up to 30 mL. This was centrifuged at 30,000×g for 90 mins at 4° C. The resulting pellet was resuspended in 1 mL of the buffer above also containing 10% glycerol. Membranes were aliquoted into cryovials which were snap-frozen in a dry-ice/ethanol bath before being stored at −80° C. until required for use.
- Scintillation Proximity Assay (PI3Kδ) [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay (PI3K-γ) [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay PI3Kδ: [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from PerkinElmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins. ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from SigmaAldrich.The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount.
- Scintillation Proximity Assay PI3Kδ:[γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay PI3K-γ: [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from PerkinElmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from SigmaAldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay PI3K-γ:[γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer).
- Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) was purchased from PerkinElmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from SigmaAldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.).The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI31(6. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer).
- Nedd8 Conjugation Inhibitory Activity A purified NAE (heterodimer of APPBP1 and UBA3) solution was prepared in the following manner. The human APPBP1 gene (NCBI Reference Sequence number: NM_003905) region corresponding to amino acids 1 to 534 of human APPBP1 protein (NCBI Reference Sequence number: NP_003896, full length: 534 amino acids) was inserted in pBacPAK9 (produced by Clontech) to construct a plasmid pBacPAK9-APPBP1 for expressing APPBP1 full-length protein having a His tag and a TEV protease-recognition sequence at the N-terminus. Next, the human UBA3 gene (NCBI Reference Sequence number: NM_003968) region corresponding to amino acids 1 to 463 of human UBA3 protein (NCBI Reference Sequence number: NP_003959, full length: 463 amino acids) was inserted in pBacPAK9 to construct a plasmid pBacPAK9-UBA3 for expressing UBA3 full-length protein. The pBacPAK9-APPBP1 or pBacPAK9-UBA3, and BacPAK6 DNA were cotransfected into insect cells (Sf9, produced by Clontech) to produce a recombinant baculovirus containing APPBP1 or UBA3 gene. The APPBP1 gene recombinant baculovirus was mixed with the UBA3 gene recombinant baculovirus, and the resulting mixture was used to infect Sf9 cells. The baculovirus-infected Sf9 cells were incubated at 28° C. with shaking for 72 hours in Grace's Insect Medium (produced by Gibco), and the collected cells were suspended in a lysis buffer (50 mM Tris-HCl, 200 mM NaCl, and 10% glycerol (pH 7.4)), followed by sonication. The sonicated cell solution was centrifuged (40,000×g, for 30 minutes) to obtain the supernatant as a crude extract. The crude extract was fractionated on a HisTrap HP column (produced by GE Healthcare) and a TALON Superflow column (produced by Clontech), followed by the addition of a TEV protease. Then, a His-tag cleavage reaction was performed at 4° C. overnight. The resulting solution was subjected to TALON Superflow column chromatography, and the unadsorbed fraction was collected. This fraction was applied to a HiLoad 16/60 Superdex 75 prep grade column equilibrated with 50 mM Tris-HCl, 200 mM NaCl, and 10% glycerol (pH 7.4), and fractionated. A fraction containing an APPBP1/UBA3 complex was concentrated to obtain a purified NAE solution. The purification above was performed entirely at 4° C. The purified NAE solution was stored at −80° C. until use.A purified GST-UBC12 solution was prepared in the following manner. The human UBC12 gene (NCBI Reference Sequence number: NM_003969) region corresponding to amino acids 1 to 183 of human UBC12 protein (NCBI Reference Sequence number: NP_003960, full length: 183 amino acids) was inserted in pGEX-4T-2 (produced by GE Healthcare) to construct a plasmid pGEX-UBC12 for expressing UBC12 full-length protein having a GST tag at the N-terminus. The pGEX-UBC12 was introduced into Escherichia coli (BL21 (DE3), produced by Stratagene), followed by culture at 37° C. for 2 hours in the presence of 1 mM isopropyl-beta-D-thiogalactopyranoside (produced by Sigma-Aldrich). The collected Escherichia coli was suspended in PBS, followed by sonication. The sonicated cell solution was centrifuged (40,000×g, for 5 minutes) to obtain the supernatant as a crude extract. A Glutathione Sepharose 4B carrier (produced by GE Healthcare) was added to the crude extract, and eluted with 50 mM Tris-HCl (pH 7.9), 150 mM NaCl, and a 10 mM reduced glutathione solution, followed by dialysis with 50 mM HEPES (pH 7.5) and a 0.05% BSA solution to obtain a purified GST-UBC12 solution. The purified GST-UBC12 solution was divided and stored at −80° C. until use.The Nedd8 conjugation inhibitory activity was measured using an AlphaScreen assay system. Each of the purified NAE solution and GST-UBC12 solution was diluted with an assay buffer (50 mM HEPES (pH 7.5), 5 mM MgCl2, 1 mM DTT, 0.05% BSA) and added to a 384-well plate (#3673, produced by Corning) containing the test compound. After reaction at room temperature for 30 minutes, a solution obtained by diluting ATP and Biotin-Nedd8
- BACE-2 Assay The compounds of the invention were assessed for their ability to inhibit BACE-1 using the following assay. The resulting values are reported in the tables above.Inhibitor IC50s at purified human autoBACE-2 were determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light. Inhibitor compounds, prepared at 3× the desired final concentration in 1×BACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1×BACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay was initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 μM for 4 μM for autoBACE-2) prepared in 1× BACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm was collected for 400 ms following a 50 s delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data was normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50 values were determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s were obtained when using raw RFU data. The Ki values were calculated from the IC50 using the Cheng-Prusoff equation.
- Binding Assay Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]— cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion (“6×His” disclosed as SEQ ID NO: 2). The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]— cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. # T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and 1050 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves.
- DGAT2 Cell-Based Assay For evaluation of the effects of DGAT2 inhibitors in a cell-based setting, cryopreserved human hepatocytes (Lot QOC, Celsis, Chicago, Ill.) were thawed and plated onto type I collagen-coated plates according to the manufacturer's instructions. After 24 hours overnight recovery period, the cells were overlayed with media containing 250 ug/ml Matrigel (BD Biosciences, San Jose, Calif.). The following day, media was aspirated and replaced with serum-free Williams Media E (Life Technologies, Grand Island, N.Y.) containing 400 uM sodium dodecanoate (Sigma-Aldrich, St. Louis, Mo.). Forty minutes later, DGAT2 inhibitors (prepared as 100× stocks in 25% DMSO, 75% Williams' Media E) were added to the desired final concentration. All wells contained a selective DGAT1 inhibitor (Example 3, WO2009016462) at a concentration (3 uM) that completely suppressed endogenous DGAT1 activity. After a 20 minute preincubation, 0.2 uCi [1,3-14C]-glycerol (American Radio Chemicals, St. Louis, Mo.) was added to each well and mixed by gentle pipetting prior to a 3 hour incubation. At this point, media was aspirated and the cells were lysed in isopropyl alcohol:tetrahydrofuran (9:1) prior to centrifugation at 3000 rpm for 5 minutes. Radiolabeled lipids were resolved using a 2-solvent system by thin layer chromatography using standard technique (solvent 1 contained ethyl acetate: isopropyl alcohol: chloroform:methanol:0.25% potassium chloride in water (100:100:100:40.2:36.1, v/v/v/v) and solvent 2 contained hexane: diethyl ether: acetic acid (70:27:3, v/v/v)). After separation, radiolabeled lipids were visualized using a Molecular Dynamics' PhosphorImager system. The half maximal inhibitory concentrations (IC50 values) were determined using Graph Pad Prism (GraphPad Software, Inc., La Jolla, Calif.).
- FRET enzyme assay The expression and purification of the 3CLpro of MERS-CoV and SARS-CoV were performed by a standard method described previously by our lab (11, 19, 20). We also cloned and expressed the 3CLpro of SARS-CoV-2. The codon-optimized complementary DNA (cDNA) of the full length of 3CLpro of SARS-CoV-2 (GenBank accession number MN908947.3) fused with sequences encoding six histidine at the N terminus was synthesized by Integrated DNA (Coralville, IA). The synthesized gene was subcloned into the pET-28a(+) vector. The expression and purification of SARS-CoV-2 3CLpro were conducted after a standard procedure described by our lab (19). Briefly, stock solutions of compounds 6a to 6k and 7a to 7k were prepared in dimethyl sulfoxide (DMSO) and diluted in assay buffer, which was composed of 20 mM Hepes buffer (pH 8) containing NaCl (200 mM), EDTA (0.4 mM), glycerol (60%), and 6 mM dithiothreitol (DTT). The protease (3CLpro of MERS-CoV, SARS-CoV, or SARS-CoV-2) was mixed with serial dilutions of each compound or with DMSO in 25 μl of assay buffer and incubated at 37°C for 30 min (MERS-CoV) or at room temperature for 1 hour (SARS-CoV and SARS-CoV-2), followed by the addition of 25 μl of assay buffer containing substrate (FAM-SAVLQ/SG-QXL 520, AnaSpec, Fremont, CA). The substrate was derived from the cleavage sites on the viral polyproteins of SARS-CoV. Fluorescence readings were obtained using an excitation wavelength of 480 nm and an emission wavelength of 520 nm on a fluorescence microplate reader (FLx800, BioTek, Winooski, VT) 1 hour after the addition of substrate. Relative fluorescence units (RFU) were determined by subtracting background values (substrate-containing well without protease) from the raw fluorescence values, as described previously (19). The dose-dependent FRET inhibition curves were fitted with a variable slope by using GraphPad Prism software (GraphPad, La Jolla, CA) to determine the IC50 values of the compounds.
- Omnia Assay Omnia Assay Protocol for Potency Assessment Against FGFR 4 Enzyme. a) [FGFR4-WT]=10 nM, [ATP]=300 uM, [Y10-Sox]=10 uM (ATP KMapp 300 uM): A 10x stock solution of FGFR4-WT (PR4380C), (from Invitrogen, Carlsbad, Calif.) corresponding to method a in Table 7, was prepared as described below. Alternatively, a 10x stock solution of FGFR4-WT (F01-11G), (SignalChem, Richmond, BC) corresponding to method b in Table 7, was prepared as described below. A solution of 1.4xATP (AS001A) and 5x Tyr-Sox conjugated peptide substrate (KNZ3101) were prepared in 1x kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10x stock, KB002A) and 0.2 mM DTT (DS001A). 5 uL of FGFR4 was pipetted into a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.), containing a 0.5 uL volume of 100% DMSO. The serially diluted compounds were prepared on a Tecan EVO100. A second addition of 10 ul of Tyr-Sox FGFR4 substrate was added to each well and the kinase reactions were started with the addition of 35 uL of 1.4xATP. The reactions were monitored every 71 seconds for 240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ~60 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (seconds) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response (Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.)).
- Omnia Assay Omnia Assay Protocol for Potency Assessment Against FGFR 4 Enzyme. b) [FGFR4-WT]=2.5 nM, [ATP]=250 uM, [Y10-Sox]=10 uM (ATP KMapp 250 uM): A 10x stock solution of FGFR4-WT (PR4380C), (from Invitrogen, Carlsbad, Calif.) corresponding to method a in Table 7, was prepared as described below. Alternatively, a 10x stock solution of FGFR4-WT (F01-11G), (SignalChem, Richmond, BC) corresponding to method b in Table 7, was prepared as described below. A solution of 1.4xATP (AS001A) and 5x Tyr-Sox conjugated peptide substrate (KNZ3101) were prepared in 1x kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10x stock, KB002A) and 0.2 mM DTT (DS001A). 5 uL of FGFR4 was pipetted into a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.), containing a 0.5 uL volume of 100% DMSO. The serially diluted compounds were prepared on a Tecan EVO100. A second addition of 10 ul of Tyr-Sox FGFR4 substrate was added to each well and the kinase reactions were started with the addition of 35 uL of 1.4xATP. The reactions were monitored every 71 seconds for 240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ~60 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (seconds) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response (Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.)).
- Omnia Assay Protocol for Potency Assessment Against EGFR (WT) and EGFR (T790M/L858R) Active Enzymes Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).[EGFR-WT]=5 nM, [ATP]=15 uM, [Y12-Sox]=5 uM (ATP KMapp˜12 uM); and [EGFR-T790M/L858R]=2.5 nM, [ATP]=20 uM, [Y12-Sox]=5 uM (ATP KMapp˜20 uM).
- PI3K-delta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3K-gamma Scintillation Proximity Assay γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3K-gamma Scintillation Proximity Assay Materials: [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3K-gamma Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3K-gamma Scintillation Proximity Assay [γ-33]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand Island, N.Y.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from SigmaAldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kdelta Scintillation Proximity Assay Materials: [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from SigmaAldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) Recombinant Human Protein was purchased from Eurofins (St. Charles, Mo.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kδ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 3.4 nM PI3Kδ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PI3Kgamma Scintillation Proximity Assay γ-33P]ATP (10 mCi/mL) and Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kγ (p110γ) Recombinant Human Protein was purchased from Life technology (Grand island, NY), ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.).The kinase reaction was conducted in polystyrene 384-well Greiner Bio-one white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 2%. The PI3Kγ assay was carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 2 μM ATP, 0.5 μCi [γ-33P] ATP, 13 nM PI3Kγ. Reactions were incubated for 120 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 163 mM potassium phosphate pH 7.8, 20% glycerol, 25 mM EDTA. The final concentration of SPA beads is 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1500 rpm for 10 min, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent of the solvent control activity versus the log of the inhibitor concentration using the GraphPad Prism 6.0 software.
- PLpro Primary Assay The PLpro primary assay, which measures protease activity with the short peptide substrate Z-RLRGG-AMC (Bachem), was performed in black flat-bottom 384-well plates containing a final reaction volume of 50 uL. The assays were assembled at room temperature as follows: 40 uL of 50 nM PLpro in buffer B (50 mM HEPES, pH 7.5, 0.1 mg/mL BSA, 0.01% Triton-X 100, and 5 mM DTT) was dispensed into wells containing 0.1−1 uL of inhibitor in DMSO or appropriate controls. The enzyme was incubated with inhibitor for 10 min prior to substrate addition. Reactions were initiated with 10 uL of 62.5 uM RLRGG-AMC in buffer B. Plates were shaken vigorously for 30 s, and fluorescence from the release of AMC from peptide was monitored continuously for 15 min on a Tecan Infinite M200 Pro plate reader (λexcitation = 360 nm; λemission = 460 nm). Slopes from the linear portions of each progress curve were recorded and normalized to plate-based controls. Positive control wells, representing 100% inhibition, included 10 uM GRL0617; negative control wells, representing 0% inhibition, included the vehicle. The selectivity of the most potent inhibitors was tested against the human deubiquitinating enzymes USP7 and USP14 (Boston Biochem). Assay conditions were similar to the PLpro primary assay, with the following substitutions: USP7 assays contained 4 nM USP7 and 0.5 uM Ub-AMC (Boston Biochem); USP14 assays contained 1.7 uM USP14, 4 uM Ub-AMC, and the addition of 5% glycerol to buffer B. PLpro activity with ISG15-AMC and Ub-AMC were assayed in a manner similar to the PLpro primary assay. PLpro and substrate concentrations were modified as follows: 80 nM PLpro was assayed with 0.5 uM Ub-AMC, and 4 nM PLpro was assayed with 0.5 uM ISG15-AMC.
- Radio-Ligand ROR gamma Binding Assay (Assay 1) Compounds of the present invention were tested for ability to bind to ROR gamma in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant ROR gamma Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM ROR gamma LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard ROR gamma inverse agonist T0901317 (SigmaAldrich, Cat. # T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves.
- Radio-Ligand RORgamma Binding Assay (Assay 1) Compounds described herein were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162×) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 min and incubated for 10 min at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 min and then for 10 min without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. # T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves. Inhibitory constants (Ki) were calculated using the following equation.
- Receptor Competition Binding Assay Receptor competition binding assays are run in a buffer made up of DPBS (1 L) (Hyclone #SH30028.03), 2.2 g BSA Fraction v (Roche #9048-46-8), 100 mL glycerol (Fischer #56-81-5) and 40 mL DMSO (reagent grade). The final wells contain 20 μg/mL aprotinin and 20 μg/mL leupeptin and 10 μM Pefabloc. Typically, receptor binding assays include radio-labeled ligands, such as 7 nM [3H]-25-hydroxycholesterol for alpha binding, 20 nM [3H]-3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for beta binding, and 6 nM [3H]-25-hydroxycholesterol for gamma binding, and 0.5 μg RORα receptor, 0.03 μg RORβ receptor, or 0.13 μg RORγ receptor per well. Assays are typically run in 96-well format. Competing test compounds are added at various concentrations ranging from about 0.4 nM to 25 μM. Non-specific binding is determined in the presence of 250 nM 25-hydroxycholesterol for RORα and RORγ binding, 250 nM 3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for RORβ binding. The sample, label and receptor solutions are combined in a 96 well assay plate (Costar 3632) and incubated overnight at room temperature, then 25 μl beads (Amersham YSi (2-5 micron) copper His-tag Spa Beads, #RPNQ0096) for a final bead concentration of 1 mg/well is added to each reaction. Plates are mixed for 30 minutes on an orbital shaker at room temperature. After an incubation of 4 hours, plates are read in a Wallac MICROBETA® counter.
- TR-FRET Kinase Assay The ability of compounds to inhibit ASK1 kinase activity was determined using a time resolved fluorescence resonance energy transfer [TR-FRET] assay utilizing biotinylated myelin basic protein [biotin-MBP] as the protein substrate. A Beckman Biomek FX liquid handling robot was utilized to spot 2 μL/well of compounds in 2.44% aqueous DMSO into low volume 384-well polypropylene plates [Nunc, #267460] to give a final concentration of between 100 μM and 0.5 nM compound in the kinase assay. A Deerac Fluidics Equator was used to dispense 3 μL/well of 0.667 ng/μL [Upstate Biotechnologies, #14-606, or the equivalent protein prepared in-house] and 0.1665 ng/mL biotin-MBP [Upstate Biotechnologies, #13-111] in buffer (85 mM MOPS, pH 7.0, 8.5 mM Mg-acetate, 5% glycerol, 0.085% NP-40, 1.7 mM DTT and 1.7 mg/mL BSA) into the plates containing the spotted compounds. The enzyme was allowed to pre-incubate with compound for 20 minutes prior to initiating the kinase reaction with the addition of 5 μL/well 300 μM ATP in buffer (50 mM MOPS, pH 7.0, 5 mM Mg-acetate, 1 mM DTT, 5% DMSO) using the Deerac Fluidics Equator. The kinase reactions were allowed to proceed for 20 minutes at ambient temperature and were subsequently stopped with the addition of 5 μL/well 25 mM EDTA using the Deerac Fluidics Equator. The Biomek FX was then used to transfer 1 μL/well of each completed kinase reaction to the wells of an OptiPlate-1536 white polystyrene plate [PerkinElmer, #6004299] that contained 5 μL/well detection reagents (1.11 nM Eu-W1024 labeled anti-phosphothreonine antibody [PerkinElmer, #AD0094] and 55.56 nM streptavidin allophycocyanin [PerkinElmer, #CR130-100] in 1×LANCE detection buffer [PerkinElmer, #CR97-100]).
- TR-FRET PIK3 Assay TR-FRET monitored the formation of 3,4,5-inositol triphosphate molecule that competed with fluorescently labeled PIPS for binding to the GRP-1 pleckstrin homology domain protein. An increase in phosphatidylinositide 3-phosphate product resulted in a decrease in TR-FRET signal as the labeled fluorophore was displaced from the GRP-1 protein binding site.Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2× Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 pM, and PI3Kγ at 2 nM. The compounds of Table 1 and Compound X ((S)-2,4-diamino-6-((1-(5-chloro-4-oxo-3-phenyl-3,4-dihydroquinazolin-2-yl)ethyl)amino)pyrimidine-5-carbonitrile) were added to the assay solution and incubated for 30 minutes at 25° C. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIPS, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 is delay and 500 is read window).The results were normalized based on positive (1 μM wortmanin) and negative (DMSO) controls, and the IC50 values for PI3Kα, β, δ, and γ were calculated from the fit of the dose-response curves to a four-parameter equation. These assays generally produced results within 3-fold of the reported mean.
- TR-FRET assay TR-FRET monitored the formation of 3,4,5-inositol triphosphate molecule that competed with fluorescently labeled PIP3 for binding to the GRP-1 pleckstrin homology domain protein. An increase in phosphatidylinositide 3-phosphate product resulted in a decrease in TR-FRET signal as the labeled fluorophore was displaced from the GRP-1 protein binding site. Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2× Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 pM, and PI3Kγ at 2 nM. The compounds of Table 1, Compound X ((S)-2-(1-((9H-purin-6-yl)amino)ethyl)-5-chloro-3-phenylquinazolin-4(3H)-one) and Compound Y ((S)-4-amino-6-((1-(5-chloro-4-oxo-3-phenyl-3,4-dihydroquinazolin-2-yl)ethyl)amino)pyrimidine-5-carbonitrile), were added to the assay solution and incubated for 30 minutes at 25° C. Additionally, compounds 19 to 116 were added to the assay solution and incubated for 30 minutes at 25° C. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 μs delay and 500 μs read window).
- scintillation proximity assay (SPA) Test A1 and A2: In order to identify binding to the human MR LBD a scintillation proximity assay (SPA) was adapted to the 384-well format. The MR-LBD (amino acids T729-K985) was expressed as N-terminal fusion with maltose binding protein in Hi5 insect cells by co-infection with recombinant MBP-MR LBD and P23 baculoviruses and crude protein lysate was used in the assay. Tritiated aldosterone is used as the ligand to generate the scintillation signal when brought into proximity of the scintillation (SPA) bead by binding to the MR LBD and test compound affinity (in IC50 values) is defined as the concentration to decrease tritiated aldosterone binding to the MR LBD by 50%.Briefly, in Test A1 the assay was run in 384 well format in 10 mM Tris-HCl, pH 7.5, 0.5 mM EDTA 20 mM NaMoO4, 0.1 mM DTT and 10% glycerol at rt. Compounds were tested in a 7 (Test A1) or 10 (Test A2) concentration response curve ranging from 10 nM to 10 μM (Test A1) or 1 nM to 37 μM (Test A2). Compounds were spotted at the bottom of a well of a 384-well PE Opti-Plate to yield final DMSO concentrations in the assay of 2%. Pre-made MBP-MR/P23 lysate: 3H-aldosterone mix (final assay concentration 7 μg/mL MBP-MR LBD/P23 lysate; 5 nM aldosterone) was added onto the top of the spotted compound and preincubated for 1 h at RT. After 1 h an equal volume anti-rabbit SPA beads (Test A1) or Imaging beads (Test A2) coupled with rabbit anti-MBP were added to the assay mixture and incubated for 3 hrs (Test A1) or >8 h (Test A2) at rt. The inhibition of the scintillation signal by displacement of the bound 3H-aldosterone by test compounds is measured by scintillation counting using a Microbeta Trilux (Wallac) (Test A1) or a by CCD camera detection using a LEADseeker (PerkinElmer) (Test A2).
- A3 PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.). The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P]ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- Enzymatic Activity Assay Recombinant HPK1 kinase domain produced via baculovirus infection of insect cells was obtained from Proteros (Proteros Biostructures #PR-0322) and was pre-activated in the presence of 2 mM ATP (Sigma-Aldrich, cat #GE27-2056-01) and 2 mM magnesium chloride for 16 hours at 4° C. The protein reaction mixture was then loaded to a desalting column (Thermo Fisher Scientific, Cat #89889) to remove excess ATP. HPK1 was eluted with buffer containing 20 mM Tris (2-Amino-2-(hydroxymethyl)propane-1,3-diol) pH 8.0, 150 mM NaCl, 2 mM dithiothreitol and 5% glycerol, and was frozen at −80° C. for later use. HPK1 dual phosphorylation was confirmed by mass spectrometry.Ten nanoliters of test compounds dissolved in DMSO at various concentrations were dispensed into a 384-well ProxiPlate (PerkinElmer #6008289). Five microliters of a solution of recombinant HPK1 diluted in HPK1 kinase assay buffer (50 mM BES [N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid], pH 7.0; 10 mM magnesium chloride; 0.01% Triton X-100; 1 mM dithiothreitol; 0.01% bovine serum albumin; 0.1 mM sodium orthovanadate) was added to the compound-containing plate and was incubated for 15 minutes at 25° C. Five microliters of a mixture of ATP (Sigma-Aldrich #A6559) and peptide substrate STK S1 (Cisbio #61ST1BLC) diluted in HPK1 kinase assay buffer was then added to start the reaction. Final concentrations were 0.15 nM for HPK1, 10 μM for ATP, and 1 μM for the STK S1 peptide substrate. The reaction mixture was incubated at 25° C. for 3 hours and was stopped with the addition of 10 μl of an EDTA (Ethylenediaminetetraacetic acid)-containing detection buffer (Cisbio #62SDBRDF) supplemented with Europium cryptate-labeled anti-phospho-serine/threonine antibodies (Cisbio #62ST1PEJ) and XL665-labeled streptavidin (Cisbio #610SAXLG). The mixture was incubated for 16 hours at room temperature and peptide phosphorylation was measured by time-resolved fluorescence energy transfer (665 nm/620 nm) on an Envision plate reader (PerkinElmer).
- HCV NS5B RdRp enzyme assay An on-bead solid phase homogeneous assay was used in a 384-well format to assess NS5B inhibitors (WangY-K, Rigat K, Roberts S, and Gao M (2006) Anal Biochem, 359: 106-111). The biotinylated oligo dT12 primer was captured on streptavidin-coupled imaging beads (GE, RPNQ0261) by mixing primer and beads in 1× buffer and incubating at room temperature for three hours. Unbound primer was removed after centrifugation. The primer-bound beads were resuspended in 3× reaction mix (20 mM Hepes buffer, pH 7.5, dT primer coupled beads, poly A template, 3H-UTP, and RNAse inhibitor (Promega N2515)). Compounds were serially diluted 1:3 in DMSO and aliquoted into assay plates. Equal volumes (5 μL) of water, 3× reaction mix, and enzyme in 3× assay buffer (60 mM Hepes buffer, pH 7.5, 7.5 mM MgCl2, 7.5 mM KCl, 3 mM DTT, 0.03 mg/mL BSA, 6% glycerol) were added to the diluted compound on the assay plate. Final concentration of components in 384-well assay: 0.36 nM template, 15 nM primer, 0.29 μM 3H-UTP (0.3 μCi), 1.6 U/μL RNAse inhibitor, 7 nM NS5B enzyme, 0.01 mg/mL BSA, 1 mM DTT, and 0.33 μg/μL beads, 20 mM Hepes buffer, pH 7.5, 2.5 mM MgCl2, 2.5 mM KCl, and 0.1% DMSO.Reactions were allowed to proceed for 24 hours at 30° C. and terminated by the addition of 50 mM EDTA (5 μL). After incubating for at least 15 minutes, plates were read on an Amersham LEADseeker multimodality imaging system.IC50 values for compounds were determined using ten different [I]. IC50 values were calculated from the inhibition using the four-parameter logistic formula y=A+((B−A)/(1+((C/x)^D))), where A and B denote minimal and maximal % inhibition, respectively, C is the IC50, D is hill slope and x represents compound concentration.
- High Throughput Biochemical Assay EGFR activity was measured using KinEASE (Cisbio), a time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay. In this assay, EGFR-catalyzes the phosphorylation of a universal Tyrosine kinase peptide substrate labeled with XL665. Europium conjugated phosphor-tyrosine specific antibody binds the resulting phosphorylated peptide. Formation of phosphorylated peptide is quantified by TR-FRET with Europium as the donor and XL665 the acceptor. The assay was performed in two main steps. The first step is the kinase reaction step and the second step is the detection step with TR-FRET reagents. In brief, test compounds 1:3 serially diluted in DMSO were delivered into Corning white, low volume, non-binding 384 well plates using the Echo 550 acoustic liquid dispenser (Labcyte®). EGFR enzyme (Human EGFR, cytoplasmic domain [669-1210] from Carna Biosciences Cat. No. 08-115) and substrates TK substrate-biotin (included in Cisbio HTRF KinEASE-TK kit Cat. No. 62TK0PEJ) were dispensed into assay plates using a Multi-Flo (Bio-Tek Instruments). The standard 10 μL reaction mixture contained 6 μM ATP (1×Km) or 12 μM ATP (2×Km), 1 μM biotinylated peptide, 0.3 nM EGFR (for 1×Km ATP) or 0.1 nM EGFR (for 2×Km ATP) in reaction buffer (10 mM MOPs, pH 7.0, 1.5% Glycerol, 0.5 mg/ml BSA, 10 mM Mg-Acetate, 1 mM DTT, 0.025% NP-40). After 60 min of incubation at room temperature, 10 μL of Stop and Detect Solution (1:400 Europium Cryptate labeled anti-phosphorylated peptide antibody solution and 125 nM strepavidin-XL665 Tracer in a 50 mM Hepes pH 7.0 detection buffer containing sufficient EDTA) was added. The plate was then further incubated for over 60 minutes at room temperature and read using an Envision 2103 Multilabeled reader (PerkinElmer) with excitation/emission/FRET emission at 340 nm/615 nm/665 nm, respectively.
- IDO1 Enzyme Assay Compounds to be tested were serially diluted in ten 3-fold steps in DMSO starting from 10 mM DMSO stocks. Compound dilutions or DMSO alone were then dispensed from the dilution plate into a Greiner black 384-well assay plate (catalog #781086) using an Echo 555 acoustic liquid handler (Labcyte).HIS-tagged IDO1 protein was recombinantly expressed in Escherichia coli using ZYP5052 autoinduction media supplemented with 500 μM delta aminolevulinic acid for 48 hours at 16 degrees Celcius. IDO1 protein was purified using Ni2+-affinity resin and size exclusion chromatography. Purified protein was then diluted in assay buffer (50 mM Tris pH 7.0, 1% glycerol, 20 uM methylene blue, 0.05% Tween-20, 20 mM sodium ascorbate, 100 units/mL catalase to obtain a final IDOL concentration of 40 nM. IDOL solution (30 uM) or buffer alone (30 uM) were dispensed to wells of the assay plate using a BioRAPTR liquid dispenser (Beckman Coulter). Assay plates containing compound and IDO1 enzyme were incubated at room temperature for 30 minutes. Afterwards, 10 μL of 400 μM tryptophan in assay buffer were added to each well of the assay plate using a BioRAPTR liquid dispenser. Plates were incubated at room temperature for 60 minutes and reactions were quenched by addition of 10 μL of 0.5 M methyl isonipecotate in dimethyl sulfoxide. Plates were sealed and incubated at 37 degrees Celcius for 4 hours or 50 degrees Celcius for 2 hours. The plates are allowed to cool and then centrifuged for 1 minute at 1000×g. The resulting fluoresence was measured in an Envision plate reader (Perkin Elmer) with a 400/25 nm excitation filter and an 510/20 nm emission filter.The fluoresence intensity of each well was corrected for the background observed in wells that did not receive IDO1 and was expressed as a fraction of the intensity observed in wells that received IDO1 enzyme and DMSO only. Potencies were calculated by linear least squares fit to the four parameter logistic IC50 equation.
- Inhibition Kinases In Vitro Assay The compounds were dissolved in 100% DMSO, and obtained solutions were serially diluted in reaction buffer (50 mM Tris pH 7.5, 10 mM MgCl2, 0.25 mM EGTA, 0.1 mM Na3VO4, 0.01% Triton X-100, 2.5 mM DTT). Recombinant FGFR1, FGFR2, FGFR3 or KDR kinase (Carna Biosciences) was diluted to final concentration of 0.1 ng/μL in the dilution buffer (50 mM Tris-HCl pH 7.5, 150 mM NaCl, 10% glycerol, 0.05% Triton X-100, 1 mM DTT). 5 μL of prepared solutions of the compounds along with 5 μL of selected kinase solution were added to each well of a 96-well plate. The plate was incubated for 10 minutes at 25° C. in plate shaker thermostat with orbital shaking at 400 rpm. To negative control wells all reagents were added except compounds and kinase, while to positive control wells all reagents except tested compounds. The reaction was initiated by adding 15 μL of solution consisting of 5× concentrated reaction buffer (50 mM Tris pH 7.5, 10 mM MgCl2, 0.25 mM EGTA, 0.1 mM Na3VO4, 0.01% Triton X-100, 2.5 mM DTT), water, 50 μM ATP, 16.67 μM IGF-1Rtide peptide (Milipore). Than the plate was incubated for 1 hour at 25° C. in plate shaker thermostat with orbital shaking at 400 rpm. Detection of ADP obtained in enzymatic reaction was performed with ADP-Glo Kinase Assay (Promega). 25 μL of ADP-Glo Reagent was added to each well of 96-well plate and the plate was incubated for 40 minutes at 25° C. in plate shaker thermostat with orbital shaking at 400 rpm. Then 50 μL of Kinase Detection Reagent was added to each well of 96-well plate and the plate was incubated for 30 minutes at 25° C. in plate shaker thermostat with orbital shaking at 400 rpm. Finally, the intensity of luminescence was measured using Victor Light luminometer (Perkin Elmer, Inc.).
- PI3K delta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.). The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- PI3Kdelta Scintillation Proximity A3 Assay [γ-33P]ATP (10 mCi/mL) was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.).The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) was purchased from PerkinElmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from SigmaAldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.). The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (PerkinElmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10 mCi/mL) was purchased from Perking Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.).The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%. Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perking Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software.
- Radio-Ligand RORgamma Binding Assay (Assay 1) Compounds of the present invention were tested for ability to bind to RORγ in a cell-free competition assay with commercially available radio-ligand (RL), 25-hydroxy [26,27-3H]-cholesterol (PerkinElmer, Cat. # NET674250UC), for a ligand binding site on a recombinant RORγ Ligand Binding Domain (LBD) protein expressed as a 6×His-Glutathione-S-Transferase (GST) fusion. The assay was performed in 96-well SPA plates (PerkinElmer, Cat. #1450-401) in 50 mM HEPES buffer, pH 7.4, containing 150 mM NaCl, 5 mM MgCl2, 10% (v/v) glycerol, 2 mM CHAPS, 0.5 mM β-octylglucopyranoside and 5 mM DTT. Tested compounds were dissolved in DMSO, and semi-log (3.162x) serial dilutions of the compounds were prepared in the same solvent. Two μL of the DMSO solutions were mixed with 28 μL of 8.6 nM 25-hydroxy [26,27-3H]-cholesterol and 50 μL of 24 nM RORγ LBD. The plate was shaken at 700 rpm for 20 mM and incubated for 10 mM at rt, after which 40 μL of poly-Lys YSi SPA beads (PerkinElmer, Cat. # RPNQ0010) were added to achieve 50 μg of the beads per well. The plate was incubated on an orbital shaker for 20 mM and then for 10 mM without agitation at rt. SPA signal for tritium beta radiation was registered on PerkinElmer Microbeta plate reader. Percent inhibition values were calculated based on the high signal obtained with DMSO control and the low signal observed with 10 μM standard RORγ inverse agonist T0901317 (SigmaAldrich, Cat. # T2320). The percent inhibition vs. concentration data were fit into a four-parameter model, and IC50 values were calculated from the fit as the concentrations corresponding to the inflection points on the dose-response curves. Inhibitory constants (Ki) were calculated using the following equation, where [RL] is the concentration in the assay and KD is a dissociation constant of 25-hydroxy [26,27-3H]-cholesterol:K i = IC 50 ( 1 + [ RL ] K D ) .
- TR-FRET Assay TR-FRET assay for retinol-induced RBP4-TTR interaction Binding of a desired RBP4 antagonist displaces retinol and induces hindrance for RBP4-TTR interaction resulting in the decreased FRET signal (FIG. 7). Bacterially expressed MBP-RBP4 and untagged TTR were used in this assay. For the use in the TR-FRET assay the maltose binding protein (MBP)-tagged human RBP4 fragment (amino acids 19-201) was expressed in the Gold(DE3)pLysS E. coli strain (Stratagene) using the pMAL-c4x vector. Following cell lysis, recombinant RBP4 was purified from the soluble fraction using the ACTA FPLC system (GE Healthcare) equipped with the 5-ml the MBP Trap HP column. Human untagged TTR was purchased from Calbiochem. Untagged TTR was labeled directly with Eu3+ Cryptate-NHS using the HTRF Cryptate Labeling kit from CisBio following the manufacturer's recommendations. HTRF assay was performed in white low volume 384 well plates (Greiner-Bio) in a final assay volume of 16 ul per well. The reaction buffer contained 10 mM Tris-HCl pH 7.5, 1 mM DTT, 0.05% NP-40, 0.05% Prionex, 6% glycerol, and 400 mM KF. Each reaction contained 60 nM MBP-RBP4 and 2 nM TTR-Eu along with 26.7 nM of anti-MBP antibody conjugated with d2 (Cisbio). Titration of test compounds in this assay was conducted in the presence of 1 uM retinol. All reactions were assembled in the dark under dim red light and incubated overnight at +4° C. wrapped in aluminum foil. TR-FRET signal was measured in the SpectraMax M5e Multimode Plate Reader (Molecular Device). Fluorescence was excited at 337 nm and two readings per well were taken: Reading 1 for time-gated energy transfer from Eu(K) to d2 (337 nm excitation, 668 nm emission, counting delay 75 microseconds, counting window 100 microseconds) and Reading 2 for Eu(K) time-gated fluorescence (337 nm excitation, 620 nm emission, counting delay 400 microseconds, counting window 400 microseconds).
- TR-FRET assays for PI3K isoforms TR-FRET monitored the formation of 3,4,5-inositol triphosphate molecule that competed with fluorescently labeled PIP3 for binding to the GRP-1 pleckstrin homology domain protein. An increase in phosphatidylinositide 3-phosphate product resulted in a decrease in TR-FRET signal as the labeled fluorophore was displaced from the GRP-1 protein binding site.Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2×Km ATP (75-500 μM), 2 μM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 pM, and PI3Kγ at 2 nM. The compounds of Table 1 and Compound X ((S)-2,4-diamino-6-((1-(5-chloro-4-oxo-3-phenyl-3,4-dihydroquinazolin-2-yl)ethyl)amino)pyrimidine-5-carbonitrile) were added to the assay solution and incubated for 30 minutes at 25° C. Additionally, Compounds 24-164 were added to the assay solution and incubated for 30 minutes at 250 in a similar manner. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 μs delay and 500 μs read window).The results were normalized based on positive (1 μM wortmanin) and negative (DMSO) controls, and the IC50 values for PI3Kα, β, δ, and γ were calculated from the fit of the dose-response curves to a four-parameter equation. These assays generally produced results within 3-fold of the reported mean.
- Time-Resolved Endpoint Proteolysis Assay Inhibitor IC50s at purified human autoBACE-2 are determined in a time-resolved endpoint proteolysis assay that measures hydrolysis of the QSY7-EISEVNLDAEFC-Eu-amide FRET peptide substrate (BACE-HTRF assay). BACE-mediated hydrolysis of this peptide results in an increase in relative fluorescence (RFU) at 620 nm after excitation with 320 nm light Inhibitor compounds, prepared at 3x the desired final concentration in 1xBACE assay buffer (20 mM sodium acetate pH 5.0, 10% glycerol, 0.1% Brij-35) supplemented with 7.5% DMSO are pre-incubated with an equal volume of autoBACE-2 enzyme diluted in 1xBACE assay buffer (final enzyme concentration 1 nM) in black 384-well NUNC plates for 30 minutes at 30° C. The assay is initiated by addition of an equal volume of the QSY7-EISEVNLDAEFC-Eu-amide substrate (200 nM final concentration, Km=8 uM for 4 uM for autoBACE-2) prepared in 1xBACE assay buffer supplemented with 7.5% DMSO and incubated for 90 minutes at 30° C. DMSO is present at 5% final concentration in the assay. Following laser excitation of sample wells at 320 nm, the fluorescence signal at 620 nm is collected for 400 ms following a 50 us delay on a RUBYstar HTRF plate reader (BMG Labtechnologies). Raw RFU data is normalized to maximum (1.0 nM BACE/DMSO) and minimum (no enzyme/DMSO) RFU values. IC50 values are determined by nonlinear regression analysis (sigmoidal dose response, variable slope) of percent inhibition data with minimum and maximum values set to 0 and 100 percent respectively. Similar IC50s are obtained when using raw RFU data. The Ki values are calculated from the IC50 using the Cheng-Prusoff equation. Examples 1 through 3, 5 through 7, 9 through 9o, 10, 11, 23, and 27a have BACE2 Ki values of less than 200 nM. Compounds 2-2, 2A-5, 3-3, 4-1 in Table A have BACE2 Ki values between about 0.5 uM and 10 uM.
- DNMT1 Enzyme Activity Assay The biochemical assay to measure DNMT1 enzyme activity relies on time-resolved fluorescence energy transfer (TR-FRET) between lumi4-Tb (donor) and d2 (acceptor) using the EPlgeneous methyltransferase assay (CisBio Cat#62SAHPEB). TR-FRET is observed when antibody specific to S-adenosylhomocysteine labeled with Lumi4-Tb is incubated with d2-labeled S-adenosylhomocysteine. TR-FRET signal is inversely proportional to the concentration of SAH, product of DNMT1 enzyme activity, in the sample. The human DNMT1 was obtained from Reaction Biology Corp. (Cat# DMT-21-124).Enzyme activity assay was carried out in a white 384-well plate in a final volume of 20 μl, as follow: 4 μl of vehicle or studied compound 2.5× concentrated prepared in assay buffer (50 mM Tris-HCl, 1 mM EDTA, 1 mM DTT, 0.1% Triton X-100, 5% glycerol pH 7.5). Final percentage of DMSO was 0.5%. 2 μl of 1 nM DNMT1 enzyme diluted in assay buffer. Final concentration was 20 nM. Start the reaction by adding 4 μl of substrate mixture containing 1 μM S-adenosylmethionine and 1 μM poly-deoxy inosine poly-deoxy cytosine (pdI-pdC) DNA. Reaction was carried out during 15 minutes at 37° C. Enzyme activity was stopped by adding 2 μl of buffer one of the EPIgeneous methyltransferase assay. After 10 minutes at room temperature, it was added 4 μl of antibody specific to S-adenosylhomocysteine labeled with Lumi4-Tb 50× diluted in buffer two of the EPIgeneous methyltransferase assay. Add 4 μl of d2-labeled S-adenosylhomocysteine 31× diluted in buffer two of the EPIgeneous methyltransferase assay. Read the plate after 1 hour of incubation at room temperature.For each well, fluorescence was measured at 620 nm and 665 nm. A ratio (665 nm/620 nm) was then calculated in order to minimize medium interferences. Positive control was obtained in the presence of the vehicle of the compounds. Negative control was obtained in the absence of G9a enzyme activity. Calculated IC50 values were determined using GraphPrism using 4-parameters inhibition curve.
- ERalpha (Wild Type), ERalpha (Y537ERalpha (Wild Type), ERalph (Y537S Mutant) and ERbeta Competition Binding Assay The purpose of the following ER competition binding assays is to determine the affinity of a test compound against ERα (wild type), ERα (Y537S mutant), and ERβ.Run the competition binding assay in a buffer containing 50 mM HEPES, pH 7.5, 1.5 mM EDTA, 150 mM NaCl, 10% glycerol, 1 mg/mL ovalbumin, and 5 mM DTT, using 0.025 μCi per well 3H-estradiol (118 μCi/mmol, 1 mCi/mL), 7.2 ng/well ERα (wild type), or 7.2 ng/well ERα (Y537S mutant) or 7.7 ng/well ERβ receptor. Add the test compound at 10 different concentrations ranging from 10,000 nM to 0.5 nM, and determine nonspecific binding in the presence of 1 μM of 17-β estradiol. Incubate the binding reaction (140 μL) for 4 hours at room temperature, and then add cold dextran-charcoal buffer (70 μL) (containing per 50 mL of assay buffer, 0.75 g of charcoal and 0.25 g of dextran) to each reaction. Mix the plates for 8 minutes on an orbital shaker at 4° C. and then centrifuge at 3000 rpm at 4° C. for 10 minutes. Transfer an aliquot (120 μL) of the mixture to another 96-well, white flat bottom plate (Costar) and add Perkin Elmer Optiphase Supermix scintillation fluid (175 μL) to each well. Seal the plates and shake vigorously on an orbital shaker. After an incubation of 2.5 hours, read the plates in a Wallac Microbeta counter. Calculate the IC50 using a 4-parameter logistic curve fit and calculate % inhibition at 10 μM. Convert the IC50 values for the compound to Ki using Cheng-Prusoff equation. The results of this assay demonstrate Examples 1, 1A, and 1B (and others) bind to recombinant ERα wild type and ERα mutant (Y537S) as shown in Table 7 below and Example 1B was also determined to bind to ERβ with a Ki (nM) ERβ competition of 0.11±0.07, n=3.
- FRET Activity Assay The human FXRalpha LBD was expressed in E. coli strain BL21(DE3) as an N-terminally GST tagged fusion protein. The DNA encoding the FXR ligand binding domain was cloned into vector pDEST15 (Invitrogen). Expression was under control of an IPTG inducible T7 promoter. The amino acid boundaries of the ligand binding domain were amino acids 187-472 of Database entry NM_005123 (RefSeq). Expression and purification of the FXR-LBD: An overnight preculture of a transformed E. coli strain was diluted 1:20 in LB-Ampicillin medium and grown at 30° C. to an optical density of OD600=0.4-0.6. Gene expression was then induced by addition of 0.5 mM IPTG. Cells were incubated an additional 6 h at 30° C., 180 rpm. Cells were collected by centrifugation (7000×g, 7 min, rt). Per liter of original cell culture, cells were resuspended in 10 mL lysis buffer (50 mM Glucose, 50 mM Tris pH 7.9, 1 mM EDTA and 4 mg/mL lysozyme) and left on ice for 30 min. Cells were then subjected to sonication and cell debris removed via centrifugation (22000×g, 30 min, 4° C.). Per 10 mL of supernatant 0.5 mL prewashed Glutathione 4B sepharose slurry (Qiagen) was added and the suspension kept slowly rotating for 1 h at 4° C. Glutathione 4B sepharose beads were pelleted by centrifugation (2000× g, 15 sec, 4° C.) and washed twice in wash buffer (25 mM Tris, 50 mM KCl, 4 mM MgCl2 and IM NaCl). The pellet was resuspended in 3 mL elution buffer per liter of original culture (elution buffer: 20 mM Tris, 60 mM KCl, 5 mM MgCl2 and 80 mM glutathione added immediately prior to use as powder). The suspension was left rotating for 15 min at 4° C., the beads pelleted and eluted again with half the volume of elution buffer than the first time. The eluates were pooled and dialysed overnight in 20 mM Hepes buffer (pH 7.5) containing 60 mM KCl, 5 mM MgCl2 as well as 1 mM dithiothreitol and 10% (v/v) glycerol. The protein was analysed by SDS-Page.
- In Vitro Assays for IDH2m R140Q Inhibitors Compounds are assayed for IDH2 R140Q inhibitory activity through a cofactor depletion assay. Compounds are preincubated with enzyme, then the reaction is started by the addition of NADPH and α-KG, and allowed to proceed for 60 minutes under conditions previously demonstrated to be linear with respect for time for consumption of both cofactor and substrate. The reaction is terminated by the addition of a second enzyme, diaphorase, and a corresponding substrate, resazurin. Diaphorase reduces resazurin to the highly fluorescent resorufin with the concomitant oxidation of NADPH to NADP, both halting the IDH2 reaction by depleting the available cofactor pool and facilitating quantitation of the amount of cofactor remaining after a specific time period through quantitative production of an easily detected fluorophore.Specifically, into each of 12 wells of a 384-well plate, 1 μl of 100× compound dilution series is placed, followed by the addition of 40 μl of buffer (50 mM potassium phosphate (K2HPO4), pH 7.5; 150 mM NaCl; 10 mM MgCl2, 10% glycerol, 0.05% bovine serum albumin, 2 mM beta-mercaptoethanol) containing 0.25 μg/ml IDH2 R140Q protein. The test compound is then incubated for one hour at room temperature with the enzyme; before starting the IDH2 reaction with the addition of 10 μl of substrate mix containing 4 μM NADPH and 1.6 mM α-KG in the buffer described above. After a further 16 hours of incubation at room temperature, the reaction is halted and the remaining NADPH measured through conversion of resazurin to resorufin by the addition of 25 μl Stop Mix (36 μg/ml diaphorase enzyme and 60 μM resazurin; in buffer). After one minute of incubation the plate is read on a plate reader at Ex544/Em590.For determination of the inhibitory potency of compounds against IDH2 R140Q in an assay format similar to the above, a similar procedure is performed, except that the final testing concentration is 0.25 μg/ml IDH2 R140Q protein, 4 μM NADPH and 1.6 mM α-KG.For determination of the inhibitory potency of compounds against IDH2 R140Q in a high throughput screening format, a similar procedure is performed, except that 0.25 μg/ml IDH2 R140Q protein is utilized in the preincubation step, and the reaction is started with the addition of 4 μM NADPH and 8 μM α-KG.
- Kinase Assay FlashPlates from Perkin Elmer (Boston, Mass., USA) with a 50 μl reaction volume are used. The reaction cocktail was pipetted in 4 steps in the following order: 15 μl of ATP solution (in H2O), 20 μl of assay buffer (see below), 5 μl of test sample in 10% DMSO, 10 μl of enzyme/substrate mixture (in H2O). The assay for all enzymes contained 60 mM HEPES-NaOH, pH 7.5, 3 mM MgCl2, 3 mM MnCl2, 3 μM Na-orthovanadate, 1.2 mM DTT, 50 μg/ml PEG20000, 1 μM [γ-33P]-ATP (approx. 8×10^5 cpm per well), protein kinase (variable amounts; see Table 1), and substrate (variable amounts). Certain assays also contained 1 mM CaCl2, 4 mM EDTA, 5 μg/ml Phosphatidylserine and 1 μg/ml 1.2-Dioleyl-glycerol. The MYLK2, CAMK1D, CAMK2A, CAMK2B, CAMK2D, CAMK4, CAMKK2, DAPK2 and EEF2K assays additionally contained 1 μg/ml Calmodulin and 0.5 mM CaCl2. The PRKG1 and PRKG2 assays additionally contained 1 μM cGMP. Recombinant Protein Kinases: All protein kinases were expressed in Sf9 insect cells or in E. coli as recombinant GST-fusion proteins or His-tagged proteins. All kinases were produced from human cDNAs, except JAK2, for which the mouse cDNA was used. Kinases were purified by affinity chromatography using either GSH-agarose (Sigma) or Ni-NTH-agarose (Qiagen). The purity of the protein kinases was examined by SDS-PAGE/coomassie staining. The identity of the protein kinases was checked by mass spectroscopy. Assays were made under license from Chemicon International Inc. for JAK2. The reaction cocktails were incubated at 30° C. for 80 minutes. The reaction was stopped with 50 μl of 2% (v/v) H3PO4, plates were aspirated and washed two times with 200 μl 0.9% (w/v) NaCl. All assays were performed with a BeckmanCoulter Biomek 2000/SL robotic system. Incorporation of 33Pi (counting of "cpm") was determined with a microplate scintillation counter (Microbeta, Wallac).
- Omnia Assay Protocol for Potency Assessment Against EGFR (WT) and EGFR (T790M/L858R) Active Enzymes The mechanics of the assay platform are best described by the vendor (Invitrogen, Carlsbad, Calif.) on their web site at the following URL: www.invitrogen.com/content.cfmpageid=11338 or www.invitrogen.com/site/us/en/home/Products-and-Services/Applications/Drug-Discovery/Target-and-Lead-Identification-and-Validation/KinaseBiology/KB-Misc/Biochemical-Assays/Omnia-Kinase-Assays.html.Briefly, 10× stocks of EGFR-WT (PV3872) from Invitrogen and EGFR-T790M/L858R (40350) from BPS Bioscience, San Diego, Calif., 1.13×ATP (AS001A) and appropriate Tyr-Sox conjugated peptide substrates (KCZ1001) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of each enzyme were pre-incubated in a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.) for 30 min. at 25° C. with a 0.5 μL volume of 50% DMSO and serially diluted compounds prepared in 50% DMSO. Kinase reactions were started with the addition of 45 μL of the ATP/Tyr-Sox peptide substrate mix and monitored every 71 seconds for 60 minutes at λex360/λem485 in a Synergy4 plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to 30 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (minutes) and then plotted against inhibitor concentration to estimate IC50 from log [Inhibitor] vs Response, Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.).[EGFR-WT]=5 nM, [ATP]=15 uM, [Y12-Sox]=5 uM (ATP KMapp 12 uM); and [EGFR-T790M/L858R]=2.5 nM, [ATP]=20 uM, [Y12-Sox]=5 uM (ATP KMapp 20 uM).
- PI3Kdelta Scintillation Proximity Assay [γ-33P]ATP (10mCi/mL) was purchased from Perkin-Elmer (Waltham, Mass.). Lipid kinase substrate, D-myo-Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)D (+)-sn-1,2-di-O-octanoylglyceryl, 3-O-phospho linked (PIP2), CAS 204858-53-7, was purchased from Echelon Biosciences (Salt Lake City, Utah). PI3Kδ (p110δ/p85α) was purchased from Millipore (Bedford, Mass.). ATP, MgCl2, DTT, EDTA, MOPS and CHAPS were purchased from Sigma-Aldrich (St. Louis, Mo.). Wheat Germ Agglutinin (WGA) YSi SPA Scintillation Beads was purchased from GE healthcare life sciences (Piscataway, N.J.).The kinase reaction was conducted in polystyrene 384-well matrix white plate from Thermo Fisher Scientific in a final volume of 25 μL. Inhibitors were first diluted serially in DMSO and added to the plate wells before the addition of other reaction components. The final concentration of DMSO in the assay was 0.5%. The PI3K assays were carried out at room temperature in 20 mM MOPS, pH 6.7, 10 mM MgCl2, 5 mM DTT and CHAPS 0.03%.Reactions were initiated by the addition of ATP, the final reaction mixture consisted of 20 μM PIP2, 20 μM ATP, 0.2 μCi [γ-33P] ATP, 4 nM PI3Kδ. Reactions were incubated for 210 min and terminated by the addition of 40 μL SPA beads suspended in quench buffer: 150 mM potassium phosphate pH 8.0, 20% glycerol. 25 mM EDTA, 400 μM ATP. The final concentration of SPA beads was 1.0 mg/mL. After the plate sealing, plates were shaken overnight at room temperature and centrifuged at 1800 rpm for 10 minutes, the radioactivity of the product was determined by scintillation counting on Topcount (Perkin-Elmer). IC50 determination was performed by fitting the curve of percent control activity versus the log of the inhibitor concentration using the GraphPad Prism 3.0 software. Compounds with an IC50 of less than 10 μM in in the assay of Example A3 are considered to be active. IC50 data for Examples 1-25 is presented in Table 3 for PI3Kδ as determined by the assay of Example A2 or A3 as indicate
- TR-FRET Assay for Retinol-induced RBP4-TTR Interaction Binding of a desired RBP4 antagonist displaces retinol and induces hindrance for RBP4-TTR interaction resulting in the decreased FRET signal (FIG. 7). Bacterially expressed MBP-RBP4 and untagged TTR were used in this assay. For the use in the TR-FRET assay the maltose binding protein (MBP)-tagged human RBP4 fragment (amino acids 19-201) was expressed in the Gold(DE3)pLysS E. coli strain (Stratagene) using the pMAL-c4x vector. Following cell lysis, recombinant RBP4 was purified from the soluble fraction using the ACTA FPLC system (GE Healthcare) equipped with the 5-ml the MBP Trap HP column. Human untagged TTR was purchased from Calbiochem. Untagged TTR was labeled directly with Eu3+ Cryptate-NHS using the HTRF Cryptate Labeling kit from CisBio following the manufacturer's recommendations. HTRF assay was performed in white low volume 384 well plates (Greiner-Bio) in a final assay volume of 16 μl per well. The reaction buffer contained 10 mM Tris-HCl pH 7.5, 1 mM DTT, 0.05% NP-40, 0.05% Prionex, 6% glycerol, and 400 mM KF. Each reaction contained 60 nM MBP-RBP4 and 2 nM TTR-Eu along with 26.7 nM of anti-MBP antibody conjugated with d2 (Cisbio). Titration of test compounds in this assay was conducted in the presence of 1 μM retinol. All reactions were assembled in the dark under dim red light and incubated overnight at +4° C. wrapped in aluminum foil. TR-FRET signal was measured in the SpectraMax M5e Multimode Plate Reader (Molecular Device). Fluorescence was excited at 337 nm and two readings per well were taken: Reading 1 for time-gated energy transfer from Eu(K) to d2 (337 nm excitation, 668 nm emission, counting delay 75 microseconds, counting window 100 microseconds) and Reading for Eu(K) time-gated fluorescence (337 nm excitation, 620 nm emission, counting delay 400 microseconds, counting window 400 microseconds). The TR-FRET signal was expressed as the ratio of fluorescence intensity: Flu665/Flu620x10,000.
- Time-Resolved Fluorescence Resonance Energy Transfer (TR-FRET) Assay The activities were measured using a time-resolved fluorescence resonance energy transfer (TR-FRET) assay. TR-FRET monitored the formation of 3,4,5-inositol triphosphate molecule that competed with fluorescently labeled PIP3 for binding to the GRP-1 pleckstrin homology domain protein. An increase in phosphatidylinositide 3-phosphate product resulted in a decrease in TR-FRET signal as the labeled fluorophore was displaced from the GRP-1 protein binding site. Class I PI3K isoforms were expressed and purified as heterodimeric recombinant proteins. All assay reagents and buffers for the TR-FRET assay were purchased from Millipore. PI3K isoforms were assayed under initial rate conditions in the presence of 25 mM Hepes (pH 7.4), and 2xKm ATP (75-500 uM), 2 uM PIP2, 5% glycerol, 5 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, and 1% (v/v) DMSO at the following concentrations for each isoform: PI3Kα, PI3Kβ, and PI3Kδ between 25 and 50 uM, and PI3Kγ at 2 nM. The compounds of Table 1 and Compound X ((S)-2,4-diamino-6-((1-(5-chloro-4-oxo-3-(pyridin-3-yl)-3,4-dihydroquinazolin-2-yl)ethyl)amino)pyrimidine-5-carbonitrile) and Compound Y ((S)-2,4-diamino-6-((1-(5-chloro-4-oxo-3-(pyridin-3-yl)-3,4-dihydroquinazolin-2-yl)ethyl)amino)pyrimidine-5-carbonitrile) were added to the assay solution and incubated for 30 minutes at 25° C. The reactions were terminated with a final concentration of 10 mM EDTA, 10 nM labeled-PIP3, and 35 nM Europium labeled GRP-1 detector protein before reading TR-FRET on an Envision plate reader (Ex: 340 nm; Em: 615/665 nm; 100 us delay and 500 us read window). The results were normalized based on positive (1 uM wortmanin) and negative (DMSO) controls, and the IC50 values for PI3K α, β, δ and γ were calculated from the fit of the dose-response curves to a four-parameter equation.
- CDK2/CycE Kinase Assay N-terminally His6-tagged recombinant catalytic domain of human Bub1 (amino acids 704-1085), expressed in insect cells (Hi5) and purified by Ni-NTA affinity chromatography and subsequent size exclusion chromatography, was used as enzyme. As substrate for the kinase reaction the biotinylated peptide biotin-Ahx-VLLPKKSFAEPG (C-terminus in amid form) was used which can be purchased e.g. form the company Biosyntan (Berlin, Germany). For the assay 50 nl of a 100 fold concentrated solution of the test compound in DMSO was pipetted into a black low volume 384 well microtiter plate (Greiner Bio-One, Frickenhausen, Germany), 2 ul of a solution of Bub1 in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCl), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1x Complete EDTA-free protease inhibitor mixture (Roche)] were added and the mixture was incubated for 15 min at 22° C. to allow pre-binding of the test compounds to the enzyme before the start of the kinase reaction. Then the kinase reaction was started by the addition of 3 ul of a solution of adenosine-tri-phosphate (ATP, 16.7 uM=>final conc. in the 5 ul assay volume is 10 uM) and substrate (1.67 uM=>final conc. in the 5 ul assay volume is 1 uM) in assay buffer and the resulting mixture was incubated for a reaction time of 60 min at 22° C. The concentration of Bub1 was adjusted depending of the activity of the enzyme lot and was chosen appropriate to have the assay in the linear range, typical concentrations were in the range of 200 ng/ml. The reaction was stopped by the addition of 5 ul of a solution of TR-FRET detection reagents (0.2 uM streptavidine-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-001] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no. AD0077, as an alternative a Terbium-cryptate-labeled anti-mouse IgG antibody from Cisbio Bioassays can be used]) in an aqueous EDTA-solution (50 mM EDTA, 0.2% (w/v) bovine serum albumin in 100 mM HEPES pH 7.5). The resulting mixture was incubated 1 h at 22° C. to allow the formation of complex between the phosphorylated biotinylated peptide and the detection reagents.
- Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1, 1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0; ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer; MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 L were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm).
- Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1, 143-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2',3'-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5x final concentration in assay buffer. MR121 substrate solution: MR121 substrate stock solution (800 uM MR121 substrate in DMSO), diluted to 2-5x final concentration in assay buffer. Test compounds (10 mM stock in DMSO, 8 uL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 uL DMSO. Row-wise serial dilutions were made by transferring 8 uL cpd solution to the next row up to row 0. The compound and control solutions were mixed five times and 2 uL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 uL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 uL of MR121 substrate solution was added (1 uM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1,1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01%Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5×final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 M MR121 substrate in DMSO), diluted to 2-5×final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- HEK TOP OncoFlash Assay In preparation of the assay, the two cell lines were plated 24 hours before beginning the test at 10000 cells per well in a 384 micro titre plate (MTP) in 30 μl growth medium. Before compound testing a dose response curve for the Wnt dependent luciferase expression was recorded by stimulating the assay cell line with human recombinant Wnt-3a (R&D, #5036-WN-010) at different concentrations for 16 hours at 37° C. and 5% CO2 followed by subsequent luciferase measurement, to determine the Wnt-3a EC50 for the HEK293 TOP cell line on the day of testing. The recombinant human Wnt-3a was thereby applied between 2500 and 5 ng/ml in two-fold dilution steps. Selective inhibitory activity for small molecules on the wildtype Wnt pathway was determined after parallel incubation of both (TOP and FOP) HEK293 reporter cell lines with a compound dilution series from 50 μM to 15 nM in steps of 3.16-fold dilutions in CAFTY buffer (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 5 mM NaHCO3, pH 7.4) containing 2 mM Ca2+ and 0.01% BSA.The compounds were thereby serially prediluted in 100% DMSO and thereafter 50 fold into the CAFTY compound dilution buffer (described above). From this dilution 10 μl were added in combination with the EC50 concentration of recombinant Wnt3a to the cells in 30 μl growth medium and incubated for 16 hours at 37° C. and 5% CO2. Thereafter luciferase assay buffer (1:1 mixture of luciferase substrate buffer (20 mM Tricine, 2.67 mM MgSO4, 0.1 mM EDTA, 4 mM DTT, 270 μM Coenzyme A, 470 μM Luciferin, 530 μM ATP, ph adjusted to pH 7.8 with a sufficient volume of 5M NaOH) and Triton buffer (30 ml Triton X-100, 115 ml glycerol, 308 mg Dithiothreitol, 4.45 g Na2HPO4. 2H2O, 3.03 g TRIS HCl (CAS Number 1185-53-1), ad 1I H2O, pH 7.8) was added in an equal volume to determine luciferase expression as a measure of Wnt signaling activity in a luminometer. The Wnt inhibitory activity was determined as IC50 of resulting dose response curves.
- HTS Assay The conditions of the assay are as follows:Microplate type: 1536 Well Black Round Bottom Polystyrene Not Treated (Corning cat no. 3936)Total reaction volume: 5 μLMRE11 concentration in the reaction: 18 nMDNA substrate concentration in the reaction: 40 nMNumber of compounds to test: 257Inhibitor concentration range tested: 7 nM-50 μMMultiplicates: 3Concentration points: 13Dilution step: 2.1Each plate contains a series of high and low signal control wells, where no compound is added:High signal: MRE11+DNA substrateLow signal: DNA substrate onlyThese are used during data evaluation.Two Extra Assay Controls:1) To check whether unwinding of DNA by the compounds alone occurs.The DNA substrate [CY5+BBQ(650)] is mixed with the compounds with no protein present.This is done as a single measurement at 25 μM inhibitor concentration.2) To check whether the compounds are able to quench the CY5.The CY5 single stranded oligo is mixed with the compounds with no protein present. This is done as a single measurement at 25 μM inhibitor concentration.The layout of the plates is created by the in-house software (CZ-Openscreen Prague) and this information is transferred to the robotic HTS station.Assay Steps1) Prepare 50 mL of master mix:16.7 mL 5× reaction buffer (150 mM Bis Tris pH 7; 5 mM DTT)1042 μL 400 mM MnCl232.3 mL H2O2) Fill the plates with 3 μL of master mix per well using MultiDrop (Thermo Scientific)3) Transfer of compounds to the plates at the robotic station with the contactless Echo dispenser (Labcyte)4) Measurement of autofluorescence with the EnVision reader (PerkinElmer)5) Prepare 20 mL of 90 nM MRE11 in T+50 buffer (25 mM Tris-HCl pH7.5, 50 mM KCl 8.7% glycerol, 0.5 mM EDTA)6) Add 1 μL of 90 nM MRE11 to the corresponding wells using MultiDrop7) Preincubation at RT for 30 min8) Prepare 20 mL of a 200 nM solution of 5′ overhang DNA substrate: 480 μL 6 μM DNA+19.52 mL H2O9) Prepare 4 mL of a 200 nM solution of the single stranded DNA (oligo 1): 8 μL 100 μM DNA+4 mL H2O10) Add 1 μL of each 200 nM DNA solution to the corresponding wells with the MultiDrop11) Fluorescence measurement with the EnVision reader every 45 minutesFluorescence readout: CY5λex/em=620/665 nmAnalysis
- High Throughput EGFR Biochemical Assay EGFR activity was measured using KinEASE (Cisbio), a time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay. In this assay, EGFR-catalyzes the phosphorylation of a universal Tyrosine kinase peptide substrate labeled with XL665. Europium conjugated phosphor-tyrosine specific antibody binds the resulting phosphorylated peptide. Formation of phosphorylated peptide is quantified by TR-FRET with Europium as the donor and XL665 the acceptor. The assay was performed in two main steps. The first step is the kinase reaction step and the second step is the detection step with TR-FRET reagents. In brief, test compounds 1:3 serially diluted in DMSO were delivered into Corning white, low volume, non-binding 384 well plates using the Echo 550 acoustic liquid dispenser (Labcyte®). EGFR enzyme (Human EGFR, cytoplasmic domain [669-1210] from Carna Biosciences Cat. No. 08-115) and substrates TK substrate-biotin (included in Cisbio HTRF KinEASE-TK kit Cat. No. 62TK0PEJ) were dispensed into assay plates using a Multi-Flo (Bio-Tek Instruments). The standard 10 μL reaction mixture contained 6 μM ATP (1×Km) or 12 μM ATP (2×Km), 1 μM biotinylated peptide, 0.3 nM EGFR (for 1×Km ATP) or 0.1 nM EGFR (for 2×Km ATP) in reaction buffer (10 mM MOPS, pH 7.0, 1.5% Glycerol, 0.5 mg/ml BSA, 10 mM Mg-Acetate, 1 mM DTT, 0.025% NP-40). After 60 min of incubation at room temperature, 10 μL of Stop and Detect Solution (1:400 Europium Cryptate labeled anti-phosphorylated peptide antibody solution and 125 nM strepavidin-XL665 Tracer in a 50 mM Hepes pH 7.0 detection buffer containing sufficient EDTA) was added. The plate was then further incubated for over 60 minutes at room temperature and read using an Envision 2103 Multilabeled reader (PerkinElmer) with excitation/emission/FRET emission at 340 nm/615 nm/665 nm, respectively. Fluorescence intensities at 615 nm and 665 nm emission wavelengths were expressed as a ratio (665 nm/615 nm). Percent inhibition was calculated as follows: % Inhibition=100x(RatioSample−Ratio0% Inhibition)/(Ratio100% Inhibition−Ratio0% Inhibition) where 0.05% DMSO (0% inhibition) was the negative control and 100 μM Staurosporine and Gefitinib (100% inhibition) was used as the positive control.
- High Throughput EGFR Biochemical Assay EGFR activity was measured using KinEASE (Cisbio), a time-resolved fluorescence resonance energy transfer (TR-FRET) immunoassay. In this assay, EGFR-catalyzes the phosphorylation of a universal Tyrosine kinase peptide substrate labeled with XL665. Europium conjugated phosphor-tyrosine specific antibody binds the resulting phosphorylated peptide. Formation of phosphorylated peptide is quantified by TR-FRET with Europium as the donor and XL665 the acceptor. The assay was performed in two main steps. The first step is the kinase reaction step and the second step is the detection step with TR-FRET reagents. In brief, test compounds 1:3 serially diluted in DMSO were delivered into Corning white, low volume, non-binding 384 well plates using the Echo 550 acoustic liquid dispenser (Labcyte®). EGFR enzyme (Human EGFR, cytoplasmic domain [669-1210] from Carna Biosciences Cat. No. 08-115) and substrates TK substrate-biotin (included in Cisbio HTRF KinEASE-TK kit Cat. No. 62TK0PEJ) were dispensed into assay plates using a Multi-Flo (Bio-Tek Instruments). The standard 10 μL reaction mixture contained 6 μM ATP (1×Km) or 12 μM ATP (2×Km), 1 μM biotinylated peptide, 0.3 nM EGFR (for 1×Km ATP) or 0.1 nM EGFR (for 2×Km ATP) in reaction buffer (10 mM MOPS, pH 7.0, 1.5% Glycerol, 0.5 mg/ml BSA, 10 mM Mg-Acetate, 1 mM DTT, 0.025% NP-40). After 60 min of incubation at room temperature, 10 μL of Stop and Detect Solution (1:400 Europium Cryptate labeled anti-phosphorylated peptide antibody solution and 125 nM strepavidin-XL665 Tracer in a 50 mM Hepes pH 7.0 detection buffer containing sufficient EDTA) was added. The plate was then further incubated for over 60 minutes at room temperature and read using an Envision 2103 Multilabeled reader (PerkinElmer) with excitation/emission/FRET emission at 340 nm/615 nm/665 nm, respectively. Fluorescence intensities at 615 nm and 665 nm emission wavelengths were expressed as a ratio (665 nm/615 nm). Percent inhibition was calculated as follows:% Inhibition=100×(RatioSample−Ratio0% Inhibition)/(Ratio100% Inhibition−Ratio0% Inhibition)where 0.05% DMSO (0% inhibition) was the negative control and 100 μM Staurosporine and Gefitinib (100% inhibition) was used as the positive control.
- Human ATX Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1, 1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row 0. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Human ATX Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1, 1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Human ATX Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org. Lett. 2006, 8, 2023) was labeled with MR121 fluorophore [CAS RN 185308-24-1], 1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 μM final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 min for 1 h (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 s, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- Human Atx Enzyme Inhibition Assay ATX inhibition was measured by a fluorescence quenching assay using a specifically labeled substrate analogue (MR121 substrate). To obtain this MR121 substrate, BOC and TBS protected 6-amino-hexanoic acid (R)-3-({2-[3-(2-{2-[2-(2-amino-ethoxy)-ethoxy]-ethoxy}-ethoxy)-propionylamino]-ethoxy}-hydroxy-phosphoryloxy)-2-hydroxy-propyl ester (Ferguson et al., Org Lett 2006, 8 (10), 2023) was labeled with MR121 fluorophore (CAS 185308-24-1,1-(3-carboxypropyl)-11-ethyl-1,2,3,4,8,9,10,11-octahydro-dipyrido[3,2-b:2′,3′-i]phenoxazin-13-ium) on the free amine of the ethanolamine side and then, after deprotection, subsequently with tryptophan on the side of the aminohexanoic acid.Assay working solutions were made as follows:Assay buffer (50 mM Tris-HCl, 140 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 0.01% Triton-X-100, pH 8.0;ATX solution: ATX (human His-tagged) stock solution (1.08 mg/mL in 20 mM bicine, pH 8.5, 0.15 M NaCl, 10% glycerol, 0.3% CHAPS, 0.02% NaN3), diluted to 1.4-2.5× final concentration in assay buffer;MR121 substrate solution: MR121 substrate stock solution (800 μM MR121 substrate in DMSO), diluted to 2-5× final concentration in assay buffer.Test compounds (10 mM stock in DMSO, 8 μL) were obtained in 384 well sample plates (Corning Costar #3655) and diluted with 8 μL DMSO. Row-wise serial dilutions were made by transferring 8 μL cpd solution to the next row up to row O. The compound and control solutions were mixed five times and 2 μL were transferred to 384 well assay plates (Corning Costar #3702). Then, 15 μL of 41.7 nM ATX solution was added (30 nM final concentration), mixed five times and then incubated for 15 minutes at 30° C. 10 μL of MR121 substrate solution was added (1 M final concentration), mixed 30 times and then incubated for 15 minutes at 30° C. Fluorescence was then measured every 2 minutes for 1 hour (Perkin Elmer plate: vision multimode reader); light intensity: 2.5%; exp. time: 1.4 sec, Filter: Fluo_630/690 nm) and IC50 values were calculated from these readouts.
- In Vitro Enzyme Activity Assay These compounds according to the afore-mentioned examples were tested for tryptophan hydroxylase (TPH) inhibitory activity in a fluorescence-based in vitro assay, using recombinant human TPH1 (Swiss-Prot: P17752) and TPH2 (Swiss-Prot: Q8IWU9).The full-length coding sequences of human TPH1 and TPH2 were PCR amplified, ligated into a MBP fusion vector (pMalc2x, New England Biolabs, MA, USA) and transformed into SCS1 (Stratagene, CA, USA) to amplify plasmid DNA. For the overexpression of TPH proteins, the constructs were transformed into Rosetta (DE3) (Novagen®/EMD Millipore, MA, USA) and cultivated in terrific broth (TB) medium (AppliChem, Darmstadt, Germany) at 37° C. When the bacterial cultures reached an OD600≈2, expression was induced with 0.5 mM IPTG (AppliChem, Darmstadt, Germany) over night at 17° C. The purification of soluble proteins started with sonication-mediated cell disruption in lysis buffer (1×PBS pH 7.4, 0.5 M NaCl, 5% Glycerol+CHAPS, DTT, PMSF, benzonase), followed by affinity purification (MBPTrap, GE Healthcare, UK) and gel filtration (26/60 Superdex 200 prep grade, GE Healthcare, UK), according to the manufacturer's protocol. The quality of protein expression and solubility was controlled by SDS-PAGE and Coomassie blue staining.The enzymatic reaction was carried out in black 96-well flat bottom plates (Corning GmbH, Wiesbaden). TPH1 and TPH2 activities were measured in a reaction mixture containing 50 mM 4-Morpholineethanesulfonic acid (MES), pH 7.0, 40 μM tryptophan, 200 mM ammonium sulfate, 25 μM ferrous ammonium sulfate, 50 μM tetrahydrobiopterin, 25 μg/ml catalase, and 7 mM DTT. The reactions were initiated by adding TPH1 or TPH2 to a final concentration of 5 μg/ml. Initial velocity of the reactions was determined by following the change of fluorescence at 330 nm (excitation wavelength=300 nm) (Infinite M200, Tecan, Crailsheim).TPH1 and TPH2 inhibition was determined by measuring a compound dose response, using a serial dilution of a 5 mM DMSO stock solution. The potency of a given compound was calculated in GraphPad PRISM 6 software (San Diego, USA) with a Nonlinear Regression fit (log(inhibitor) vs. response-variable slope) using the relative fluorescence units (RFU) of the sample triplicates.
- In Vitro JAK Kinase Inhibition Assay Tested compounds were dissolved in 100% DMSO, and obtained stock solutions were serially diluted in the reaction buffer (50 mM Tris pH 7.5, 10 mM MgCl2, 0.25 mM EGTA, 0.1 mM Na3VO4, 0.01% Triton X-100, 2.5 mM DTT). Recombinant kinases JAK1 (ProQinase), JAK2, or JAK3 (Carna Biosciences) were diluted in the dilution buffer (50 mM Tris-HCl pH 7.5, 150 mM NaCl, 10% glycerol, 0.05% Triton X-100, 1 mM DTT) to the final concentration 3 ng/μL (JAK1), 0.1 ng/μL (JAK2), or 0.2 ng/μL (JAK3). 5 μL of obtained solution of the compounds and 5 μL of the solution of respective kinases were added to the well of a 96-well plate. To initiate interaction between tested compounds and an enzyme, the plate was incubated for 10 minutes at 25° C. in a Plate-Thermo-Shaker with orbital stirring at 400 rpm. Wells of a negative control contained all reagents as mentioned above with the exception of tested compounds and kinase, and wells of a positive controls contained all reagents as mentioned above with the exception of tested compounds. Enzymatic reaction was initiated by the addition of 15 μL of the following solution: 5× concentrated reaction buffer (50 mM Tris pH 7.5, 10 mM MgCl2, 0.25 mM EGTA, 0.1 mM Na3VO4, 0.01% Triton X-100, 2.5 mM DTT), water, 30 μM ATP and for particular kinases: JAK1—60 μM peptide IRS-1 (Enzo), JAK2 or JAK3—10 μM peptide IGF-1Rtide (Lipopharm). Then the plate was incubated for 1 hour at 25° C. in a Plate-Thermo-Shaker, with orbital stirring at 400 rpm. Detection of ADP formed in the enzymatic reaction was then performed using ADP-Glo Kinase Assay kit (Promega). For this purpose, to the well of the 96-well plate 25 μL of ADP-Glo Reagent were added, and the plate was incubated for 40 minutes at 25° C. in a Plate-Thermo-Shaker with orbital stirring at 400 rpm. Then to the well of the 96-well plate 50 μL of Kinase Detection Reagent were added and the plate was incubated for 30 minutes at 25° C. in a Plate-Thermo-Shaker with orbital stirring at 400 rpm. After incubation, luminescence intensity was measured using Victor×Light luminometer (Perkin Elmer, Inc.).
- In Vitro Plasma Kallikrein Inhibition Assay The chromogenic substrate D-Pro-Phe-Arg-pNa, 2HCl (BIOPHEN CS-31(02) from Hyphen BioMed, Neuville-Sur-oise, France) was dissolved in 5 mL deionized water and stored at 4° C. Concentration was determined in the spectrophotometer at 342 nm using an extinction coefficient of 8270. All other chemicals were of analytical grade.Human plasma kallikrein was purchased from Enzyme Research Labs (South Bend, Ind., USA, batch HPKa 2830). A stock solution of 7 μM in 50% glycerol was stored at −20° C.Enzyme reactions were conducted in assay buffer comprised of 20 mM HEPES at pH 7.4, 150 mM NaCl, 0.1% PEG-8000 and 0.01% Triton X-100.Both enzyme and substrate were diluted in assay buffer.The compound solutions as well as the enzyme and the substrate solutions were transferred to 96-well plates (Clear, UV-Star, Flat-bottom, Half-Area plates; cat. No. 675801 Greiner Bio-one, purchased from VWR International, Arlington Heights, Ill., USA) using a Rainin LTS 96-channel pipettor (Rainin, Columbus, Ohio, USA). Plate measurements were conducted using a SPECTROStar Nano reader (BMG Labtech, San Francisco, Calif., USA). The SPECTROStar Nano is a spectrophotometer and absorbance was measured at 405 nm. We used discrete wavelength, precise, kinetic reads of 15 cycles with a 60 sec cycle time.Determination of IC50 valuesFor the determination of IC50 values, the assays were performed at room temperature in 96-well plates with a total assay volume of 85 μL per well. The test compound was dissolved in 100% DMSO. The compounds were serially diluted in DMSO in a 7 point dose response. For the assays, 66.5 μL of protease solution (protease in assay buffer) was added per well followed by the addition of 8.5 μL of compound in 100% DMSO. The final assay concentration of the human plasma kallikrein was 250 μM. After 30 min. incubation at room temperature on an orbital shaker, the reactions were started by the addition of 10 μL substrate solution (in assay buffer, final assay concentration was 600 uM). After the addition of the substrate solution the final DMSO concentration was 10%. The plate was placed again on the shaker for 5 sec, spun at 2000 rpm for 5 sec and read on the spectrophotometer. The effect of the compound on the enzymatic activity was obtained from the linear part of the progress curves and determined after 15 minutes.
- Inhibition Mass Spectrometry Assay 1. A 10 mM test compound was dissolved in 100% DMSO and serially diluted 1 in 4. 100 nL of this dilution series was then added to a 384 well, v bottom polypropylene plate, excluding columns 6 and 18. 100 nL of DMSO was added to columns 6 and 18 as controls wells. Assay dilution gave a top final assay concentration of test compound of 100 μM 2. 50 ul of 1% formic acid in laboratory grade water was added to column 18 using a multidrop combi dispenser to act as a pre stopped assay control. 3. 5 uL of enzyme solution containing 50 nM of purified recombinant Full length Flag-LRRK2 in assay buffer (50 mM Hepes (pH 7.2), 10 mM MgCl2, 150 mM NaCl, 5% glycerol, 0.0025% triton X-100 and 1 mM DTT) was added to all wells using a multidrop combi dispenser, giving a final assay concentration of 25 nM LRRK2 enzyme. This resulted in column 6 (enzyme plus DMSO) giving 0% inhibition and column 18 giving 100% inhibition (pre stopped control). Test plates were then incubated for 30 minutes at room temperature. 4. 5 uL substate solution containing 50 uM LRRKtide peptide substrate and 4 mM ATP was added to all wells of the plate using a multidrop combi dispenser giving a final assay concentration of 25 uM LRRKtide and 2 mM ATP. Test plates were then incubated for 1 hour at room temperature. (Incubation may vary depending on rate and linearity of reaction with different enzyme batches). 5. 50 ul of 1% formic acid in laboratory grade water was added to all wells (minus column 18) to quench the reaction, and plates were centrifuged at 3000 rpm for 10 minutes. Test plates were then analysed on an Agilent RapidFire High Throughput solid phase extraction system coupled to AB Sciex API 4000 triple quadropole mass spectrometer with the following setting: RapidFire Settings: Sip Height=2 mm, Aspirate=500 ms, Load time=3000 ms, Elution time=3000 ms, Requilibration=500 ms, Flow rates: pump 1=1.5 mL/min, pump 2 1.25 mL/min pump 3=0.8 mL/min.
- Ki Determination for Genotypes 1b and 3a NS3 Protease Purified NS3 protease domain (amino acids 1-181) of the genotype 1b and 3a virus were generated as above. The internally quenched fluorogenic depsipeptide substrate Ac-DED(Edans)-EEAbuΨ[COO]ASK(Dabcyl)-NH2 and a synthetic peptide containing the hydrophobic core residues of the NS4A protein cofactor (KKGSVVIVGRIILSGRKK; NS4A peptide) were obtained from Anaspec, Inc. (San Jose, Calif.). Other chemicals and biochemicals were of reagent grade or better and were purchased from standard suppliers.Reactions were run at room temperature in buffer consisting of 50 mM HEPES, 40% glycerol, 0.05% Triton X-100, 10 mM DTT, and 10% DMSO. The final assay solutions contained 50 pM NS3 genotype 1 b protease or 200 pM genotype 3a protease, 20 μM NS4A peptide, and 4 μM substrate (genotype 1b) or 2 μM substrate (genotype 3a). Inhibitor concentrations varied from 100 nM to 5 pM in 3-fold dilutions, and no-inhibitor controls were included.Compound dilutions were made in DMSO at 20× final concentration. Reaction mixtures were prepared in 96-well assay plates. A solution of enzyme and NS4A peptide in assay buffer (25 μL volume with both reagents at 4× final concentration) was mixed with 45 μL assay buffer and 5 μL of either inhibitor or DMSO, and pre-incubated at room temperature for 1 hour. The reaction was started by addition of 25 μL substrate solution at 4× final concentration. Plates were mixed vigorously for 5-10 seconds and reactions were allowed to proceed for 90 minutes, fluorescence was measured every 30 s between 90 and 120 minutes reaction time using a Tecan InfiniTe M1000 or PerkinElmer Envision multimode plate reader with an excitation wavelength of 340 nm and an emission wavelength of 490 nm.Rates were calculated from the progress curves at steady state, in the time frame of 90-120 minutes after addition of substrate. To determine the Ki, rates were plotted as a function of inhibitor concentration, and the data were fit with equation 1 (Morrison, J. F., Biochimica et Biophysica Acta 1969, 185, 269-286) to calculate Ki app using GraphPad Prism 5. Active fraction of enzyme was determined by active site titration with known potent inhibitors. Ki was calculated from Ki app/(1+[[S]/Km]).
- Kinase Assay In a typical assay 11 different concentrations of each compound (0.1 nM, 0.33 nM, 1.1 nM, 3.8 nM, 13 nM, 44 nM, 0.15 μM, 0.51 μM, 1.7 μM, 5.9 μM and 20 μM) were tested in duplicate within the same microtiter plate. To this end, 100-fold concentrated compound solutions (in DMSO) were previously prepared by serial dilution (1:3.4) of 2 mM stocks in a clear low volume 384-well source microtiter plate (Greiner Bio-One, Frickenhausen, Germany), from which 50 nl of compounds were transferred into a black low volume test microtiter plate from the same supplier. Subsequently, 2 μl of Bub1 (the final concentration of Bub1 was adjusted depending on the activity of the enzyme lot in order to be within the linear dynamic range of the assay: typically ˜200 ng/ml were used) in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCl), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1× Complete EDTA-free protease inhibitor mixture (Roche)] were added to the compounds in the test plate and the mixture was incubated for 15 min at 22° C. to allow pre-equilibration of the putative enzyme-inhibitor complexes before the start of the kinase reaction, which was initiated by the addition of 3 μl 1.67-fold concentrated solution (in assay buffer) of adenosine-tri-phosphate (ATP, 10 μM final concentration) and peptide substrate (1 μM final concentration). The resulting mixture (5 μl final volume) was incubated at 22° C. during 60 min., and the reaction was stopped by the addition of 5 μl of an aqueous EDTA-solution (50 mM EDTA, in 100 mM HEPES pH 7.5 and 0.2% (w/v) bovine serum albumin) which also contained the TR-FRET detection reagents (0.2 μM streptavidin-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-002] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no. AD0077, alternatively a Terbium-cryptate-labeled anti-mouse IgG antibody from Cisbio Bioassays can be used]).
- Primer Extension Assay (((Guanine-9-yl) propan-2-oxy) methyl) phosphonic acid diphosphate (PMPGpp) acts as a chain terminator and competes with dGTP.Purified human telomerase was incubated with d(TTAGGG)3 (SEQ ID NO: 1) and deoxy-nucleoside triphosphates for 90 minutes at 37° C. All reactions were done in the presence of 200 dTTP and 10 μM dATP (50,000 cpm/pmol a-33P-dATP). Activity was determined by incubating affinity purified telomerase extract with 1 μM primer [d(TTAGGG)3] (SEQ ID NO: 1), 200 μM dTTP, 50 μM dGTP, 10 μM dATP, 10 μCi [α-33P]dATP (2000-4000 Ci/mmol) in a buffer containing 50 mM (N-2-hydroxyethyl piperazine-N′-3 propanesulfonic acid)-NaOH pH 8.5, 1 mM MgCl2, 1 mM DTT, 5% glycerol, 0.5 mM EGTA and 100 mM KOAc in a final reaction volume of 40 μl. Primer extension products were analyzed on a 15% polyacrylamide gel containing 7 M urea. A characteristic telomerase ladder has multiple bands. If a compound is not a substrate then (TTAGGG)3TTA (21 nt) (SEQ ID NO: 2). If a compound is a chain terminator then (TTAGGG)3TTAG* (22 nt) (SEQ ID NO: 3).FIG. 1 is a photograph of a 15% polyacrylamide gel containing 7 M urea showing the primer extension products in the presence of compounds. Reactions containing 50 or 100 μM dGTP, (lanes 1 and 2) show a characteristic 6 nucleotide ladder. Lanes 8-11 contain increasing concentrations of PMPGpp (ID#142692) in addition to 50 μM dGTP. Lane 12 contains only 50 μM PMPGpp (ID#142692). Lanes 3-7 show a comparison using the known chain terminator, 3′-azido-dGTP.IC 50s for (R)-PMPGpp and (S)-PMPGpp are shown in Table 3. (R)-(((Guanine-9-yl) propan-2-oxy) methyl) phosphonic acid diphosphate is efficiently recognized by human telomerase and added to the 3′ end of a telomeric primer resulting in chain termination. The molecule competes with dGTP and when measured in a cell free assay, using purified telomerase and dGTP concentrations of 50 μM, shows an IC50 of about 1.0 μM.
- Protease-Free PPIase Assay The protease-free PPIase assay measures the rate of cis to trans conversion of a peptide substrate catalyzed by the enzyme cyclophilin A. Addition of a cyclophilin A inhibitor (e.g., a test compound) slows the catalyzed rate and a Ki value is obtained. A Ki value of less than 10 nM demonstrates that the test compound is a potent inhibitor of cyclophilin A.MaterialsAssay Buffer:35 mM HEPES pH 7.8, filtered through a 0.2 μm filter. 50 μM DTT was added prior to use each day and then the buffer was stored on ice.Enzyme:Human recombinant cyclophilin A (Cyp A) (Sigma C3805) enzyme was diluted to 1 μM with enzyme dilution buffer (20 mM HEPES pH 7.8, 40% glycerol, 50 μM DTT and 1 μM BSA) and stored at −20° C.Substrate:Succinimide-Ala-Ala-Pro-Phe-p-nitroanilide (SUC-AAPF-pNA) (from Bachem AG, L-1400), 20 mg/ml prepared in 0.5 M LiCl in trifluoroethanol.MethodAll readings were taken with an Agilent 8453 Spectrophotometer which includes of a cuvette holder, stirrer and chiller to maintain a stirred cuvette temperature of 10.0±0.1° C. The temperature is monitored by the use of a temperature probe. To prevent UV degradation of test compounds, the light below 290 nm was blocked using a glass slide in the light path. 1.5 ml of the assay buffer was put into a 3 ml quartz cuvette and cooled to 10.0±0.1° C. while stirring (vigorous but not so fast as to produce cavitation). The inhibitor was diluted in 100% DMSO, and then added to the assay to a maximum final concentration of 0.5% DMSO in the assay. A blank spectrum was obtained, then 3 μL of enzyme was added (2 nM final concentration) and then 3 μL substrate (60 μM final concentration) added. The absorbance was measured at 330 nm for 300 s or 500 s for blank runs (NOTE: the substrate must be added in one quick injection and the measurements started immediately to minimize mixing errors).A first order rate equation was fitted to the absorbance data, for each concentration of inhibitor, to obtain the rate constant (the first 10 to 15 seconds were excluded as mixing causes errors in this portion of curve). The catalytic rate was calculated from the enzymatic rate constant minus the background rate constant. An exponential curve was generated using the catalytic rate constants versus the inhibitor concentration to obtain the Ki value for the inhibitor. The Ki value is indicative of the binding affinity between the test compound and cyclophilin A.
- Syk Kinase Test Recombinant human Syk (amino acids 342-635) was expressed as a fusion protein with an N-terminal GST tag, affinity-purified and deep-frozen at a concentration of approx. 50-100 μM in storage buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 0.2% BSA; 0.01% CHAPS; 100 μM Na3VO4; 0.5 mM DTT, 10% glycerol) at −80° C. until use.The catalytic activity of the GST-Syk kinase fusion protein was determined using the Kinase Glo® Luminescence Kinase test (Promega; V6712). In this homogeneous test the amount of ATP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ATP still present and thus correlates inversely with the activity of the kinase.MethodThe test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 1 mM. Serial Dilution is done in 100% DMSO. All further dilutions of the substances were carried out with test buffer (25 mM HEPES pH7.5; 25 mM MgCl2; 5 mM MnCl2; 50 mM KCl; 0.2% HSA; 0.01% CHAPS; 100 μM Na3VO4; 0.5 mM DTT). Dilution steps and concentration range were adapted according to need. 7 μl aliquots of these dilutions were transferred into a 384-well Optiplate (Perkin Elmer, #6007290). GST-Syk was diluted to 12 nM in the test buffer and 5 μl of this dilution were used in the kinase test (final concentration of Syk=4 nM in a total volume of 15 μl). After 15 minutes incubation at room temperature 3 μl of a mixture of 750 nM ATP and 100 μg/ml poly (L-Glutamic acid L-Tyrosine 4:1), Fluka #81357) in test buffer were added to each well and the incubation was continued for a further 60 minutes at room temperature.Positive controls are the reaction mixtures that contain no test substance; negative controls (blanks) are reaction mixtures that contain no kinase.After 60 minutes, 10 μl Kinase-Glo® solution (Promega, Cat. # V6712) (heated to room temperature) were added to each well and incubation was continued for a further 15 minutes. The plates were read in Envision Luminescence Reader (Perkin-Elmer).
- TR-FRET Kinase Assay The ability of compounds to inhibit ASK1 kinase activity was determined using a time resolved fluorescence resonance energy transfer [TR-FRET] assay utilizing biotinylated myelin basic protein [biotin-MBP] as the protein substrate. A Beckman Biomek FX liquid handling robot was utilized to spot 2 μL/well of compounds in 2.44% aqueous DMSO into low volume 384-well polypropylene plates [Nune, #267460] to give a final concentration of between 100 μM and 0.5 nM compound in the kinase assay. A Decrac Fluidics Equator was used to dispense 3 μL/well of 0.667 ng/μL [Upstate Biotechnologies, #14-606, or the equivalent protein prepared in-house] and 0.1665 ng/mL biotin-MBP [Upstate Biotechnologies, #13-111] in buffer (85 mM MOPS, pH 7.0, 8.5 mM Mg-acetate, 5% glycerol, 0.085% NP-40, 1.7 mM DTT and 1.7 mg/mL BSA) into the plates containing the spotted compounds. The enzyme was allowed to pre-incubate with compound for 20 minutes prior to initiating the kinase reaction with the addition of 5 μL/well 300 μM ATP in buffer (50 mM MOPS, pH 7.0, 5 mM Mg-acetate, 1 mM DTT, 5% DMSO) using the Decrac Fluidics Equator. The kinase reactions were allowed to proceed for 20 minutes at ambient temperature and were subsequently stopped with the addition of 5 μL/well 25 mM EDTA using the Deerac Fluidics Equator. The Biomek FX was then used to transfer 1 μL/well of each completed kinase reaction to the wells of an OptiPlate-1536 white polystyrene plate [PerkinElmer, #6004299] that contained 5 μL/well detection reagents (1.11 nM Eu-W1024 labeled anti-phosphothreonine antibody [PerkinElmer, #AD0094] and 55.56 nM streptavidin allophycocyanin [PerkinElmer, #CR130-100] in 1×LANCE detection buffer [PerkinElmer, #CR97-100]). The TR-FRET signal was then read on a Perkin. Elmer Envision plate reader after incubating the plates at ambient temperature for 2 hours. The 100% inhibition positive control wells were generated by switching the order of addition of the EDTA and ATP solutions described above. These wells and 0% inhibition wells containing spots of 2.44% DMSO at the beginning of the assay were used in calculating the % inhibition for the test compounds.
- Tec, Txk, and ITK Activities Inhibition Assay The inhibitory activities of the compound to Tec, Txk, and ITK of human were performed by Eurofins Pharma Discovery Services UK Limited (UK) of the United Kingdom. In the case of Km ATP, the radioactive protein kinase method was adopted by the test. The kinase was diluted with buffer solution (20 mM MOPS, 1 mM EDTA, 0.01% Brij-35, 5% Glycerol, 0.1% 6-mercaptoethanol, 1 mg/mL BSA) before the reaction. The compound was dissolved in 100% DMSO and was of 50-fold final reaction concentration.ITK reaction solution included 8 mM MOPS pH 7.0, 0.2 mM EDTA, 0.33 mg/mL myelin basic protein, 10 mM magnesium acetate, and [γ-33P]-ATP (about 500 cpm/pmol), 200 μM ATP-Mg was added, after mixing, the reaction was started, the incubation was performed for 40 minutes at room temperature, and 3% phosphoric acid solution was added to terminate the reaction. 10 μl (reaction solution) was placed on P30 filtration membrane, washed with 75 mM phosphoric acid for 5 minutes, and dried with methanol for one time, and then scintillation counting was performed.Active type Tex reaction solution contained 8 mM MOPS pH 7.0, 0.2 mM EDTA, 1 mM Na3VO4, 5 mM Na-6-phosphoglycerol, 400 μM EFPIYDFLPAKKK, 10 mM magnesium acetate, and [γ-33P]-ATP (about 500 cpm/pmol), 120 μM ATP-Mg was added, after mixing, the reaction was started, the incubation was performed for 40 minutes at room temperature, and 3% phosphoric acid solution was added to terminate the reaction. 10 μl (reaction solution) was placed on P30 filtration membrane, washed with 75 mM phosphoric acid for 5 minutes, and dried with methanol for one time, and then scintillation counting was performed.TxK reaction solution contained 8 mM MOPS pH 7.0, 0.2 mM EDTA, 250 μM GEEPLYWSFPAKKK, 10 mM magnesium acetate, and [γ-33P]-ATP (about 500 cpm/pmol), 200 μM ATP-Mg was added, after mixing, the reaction was started, the incubation was performed for 40 minutes at room temperature, and 3% phosphoric acid solution was added to terminate the reaction, 10 μl (reaction solution) was placed on P30 filtration membrane, washed with 75 mM phosphoric acid for 5 minutes, and dried with methanol for one time, and then scintillation counting was performed.
- Time-Resolved Fluorescence Energy Transfer (TR-FRET) Kinase Assay In a typical assay 11 different concentrations of each compound (0.1 nM, 0.33 nM, 1.1 nM, 3.8 nM, 13 nM, 44 nM, 0.15 μM, 0.51 μM, 1.7 μM, 5.9 μM and 20 μM) were tested in duplicate within the same microtiter plate. To this end, 100-fold concentrated compound solutions (in DMSO) were previously prepared by serial dilution (1:3.4) of 2 mM stocks in a clear low volume 384-well source microtiter plate (Greiner Bio-One, Frickenhausen, Germany), from which 50 nL of compounds were transferred into a black low volume test microtiter plate from the same supplier. Subsequently, 2 μL of Bub1 (the final concentration of Bub1 was adjusted depending on the activity of the enzyme lot in order to be within the linear dynamic range of the assay: typically 200 ng/mL were used) in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCl), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1× Complete EDTA-free protease inhibitor mixture (Roche)] were added to the compounds in the test plate and the mixture was incubated for 15 min at 22° C. to allow pre-equilibration of the putative enzyme-inhibitor complexes before the start of the kinase reaction, which was initiated by the addition of 3 μL 1.67-fold concentrated solution (in assay buffer) of adenosine-tri-phosphate (ATP, 10 μM final concentration) and peptide substrate (1 μM final concentration). The resulting mixture (5 μL final volume) was incubated at 22° C. during 60 min., and the reaction was stopped by the addition of 5 μL of an aqueous EDTA-solution (50 mM EDTA, in 100 mM HEPES pH 7.5 and 0.2% (w/v) bovine serum albumin) which also contained the TR-FRET detection reagents (0.2 μM streptavidin-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-001] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no.
- Aurora B Kinase Test Recombinant human Aurora B (amino acids 1-344, clone number DU1773, Molecular weight 40.2 kDa, University of Dundee) was expressed as a fusion protein with an N-terminal His tag, affinity-purified and deep-frozen at a concentration of approx. 0.25-0.5 mg/ml in storage buffer (50 mM Tris-HCl pH 8; 25 mM Na-ß-glycerophosphat; 0.1 mM EGTA; 150 mM NaCl; 0.03% Brij-35; 1 mM DTT and 10% glycerol) at −80° C. until use.The activity of the Aurora B kinase protein was determined using the ADP Glo® Luminescence Kinase test (Promega; V9103X). In this homogeneous test the amount of ADP remaining after the kinase reaction is quantified by a luciferin-luciferase reaction using luminescence. The luminescence signal obtained correlates with the amount of ADP still present and thus correlates with the activity of the protein kinase.MethodThe test compounds were dissolved in 100% DMSO at a concentration of 10 mM and diluted in DMSO to a concentration of 5 mM. Serial Dilution is done in 1:10 steps in 100% DMSO. All further dilutions of the substances were carried out with test buffer (50 mM Hepes, pH 7.5, 10 mM MgCl2, 1 mM EGTA, 60 μM Ultra Pure ATP, 0.01% Brij35, 0.1% BSA, 5 mM 3-Glycerophosphate) until a concentration was reached which was 2.5 times above the final test concentration (final concentration of the compounds: 50 μM to 0.005 nM). 4 μl aliquots of these dilutions were transferred into a 384-well Optiplate (Perkin Elmer, #6007290). His-Aurora B was diluted to 125 nM in the test buffer and 4 μl of this dilution were used in the kinase test (final concentration of Aurora B=50 nM in a total volume of 10 μl). After 15 minutes incubation at room temperature 2 μl of 250 μM substrate ([LRRLSLGLRRLSLGLRRLSLGLRRLSLG]; University of Dundee) in test buffer were added to each well and the incubation was continued for a further 60 minutes at room temperature.Positive controls are the reaction mixtures that contain no test substance; negative controls (blanks) are reaction mixtures that contain no kinase.After 60 minutes, 10 μl ADP-Glo® solution (ADP-Glo Reagent #V912B Promega) (heated to room temperature) were added to each well and incubation was continued for a further 40. minutes. Then 20 μl Kinase detection mix (Detection Buffer #V913B Promega; Kinase Detection Substrate #V914B Promega) were added and incubated for 40 minutes at room temperature. The plates were read in Envision Luminescence Reader (Perkin-Elmer).
- B-RAF (V600E) Kinase Assay In a dilution series 10 uL/well of test substance solution are placed in a multiwell plate. The dilution series is selected so that generally a range of concentrations of 2 uM to 0.119 nM or 0.017 nM is covered. If necessary the initial concentration of 2 uM is changed to 50 uM, 10 uM or 0.4 uM or 0.2857 uM and further dilution is carried out accordingly. The final concentration of DMSO is 5%. 10 uL/well of the B-Raf (V600E)-kinase solution are pipetted in (containing 0.5 ng B-Raf (V600E)-kinase (e.g. from Upstate) in 20 mM Tris-HCl pH 7.5, 0.1 mM EDTA, 0.1 mM EGTA, 0.286 mM sodium orthovanadate, 10% glycerol, 1 mg/mL bovine serum albumin, 1 mM dithiothreitol) and the mixture is incubated for 1 h at RT under with shaking. The kinase reaction is started by the addition of 20 uL/well ATP solution [final concentration: 250 uM ATP, 30 mM Tris-HCl pH 7.5, 0.02% Brij, 0.2 mM sodium orthovanadate, 10 mM magnesium acetate, 0.1 mM EGTA, phosphatase cocktail (Sigma, #P2850, dilution recommended by the manufacturer)] and 10 uL/well MEK1 solution [containing 50 ng biotinylated MEK1 (prepared from purified MEK1 according to standard procedure, e.g. with EZ-Link Sulpho-NHS-LC-Biotin reagent, Pierce, #21335)] and carried out for 60 min at RT with constant shaking. The reaction is stopped by the addition of 12 uL/well of a 100 mM EDTA solution and incubation is continued for a further 5 min. 55 uL/well of the reaction solution are transferred into a streptavidin-coated plate (e.g. Streptawell HighBond, Roche, #11989685001) and shaken gently for 1 h at RT, in order to bind biotinylated MEK1 to the plate. After elimination of the liquid the plate is washed five times with 200 uL/well of 1ÿPBS and 100 uL/well solution of primary antibody plus europium-labelled secondary antibody [Anti Phospho-MEK (Ser217/221), Cell Signaling, #9121 and Eu-N1 labelled goat-anti-rabbit antibody, Perkin Elmer, #AD0105] is added, the primary antibody is diluted 1:2000 and the secondary antibody is diluted to 0.4-0.5 ug/mL in Delfia Assay Buffer (Perkin Elmer, #1244-111). After 1 h shaking at RT the solution is poured away and washed five times with 200 uL/well Delfia Wash Buffer (Perkin Elmer, #4010-0010/#1244-114). After the addition of 200 uL/well Enhancement Solution (Perkin Elmer, #4001-0010/#1244-105) the mixture is shaken for 10 min at RT and then measured in a Wallac Victor using the program "Delfia Time Resolved Fluorescence (Europium)". IC50 values are obtained from these dosage-activity curves using a software program (GraphPadPrizm).
- Expression and Purification of Active Kinases Full length CDPK1 was PCR amplified from a T. gondii RH cDNA library generated using the SMART cDNA synthesis kit (Clontech). The primers contained restriction sites that were used to directionally clone the PCR product, NdeI to XhoI, into the pET-22b(+) vector, in frame with a C-terminal hexahistidine tag. Single mutation of the codon corresponding to glycine 128 was achieved using the QuikChange II Site-Directed Mutagenesis Kit (Agilent Technologies), with specific primers designed according to manufacturer instructions. Plasmids were transformed into BL21(DE3)V2RpAcYc-LIC+LamP E. coli, which express the LamP phosphatase, as described previously. Following overnight growth in Terrific Broth at 37° C., cells were diluted 1:50 in fresh medium and cultured for 3 h at 37° C., then cooled to 15° C., induced by addition of 1 mM IPTG, and cultured overnight. Cells were lysed in CelLyticB solution (Sigma Aldrich), and proteins purified using HIS-select Nickel Affinity Gel following manufacturers instructions (Sigma-Aldrich). Purified proteins were dialyzed (50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 0.125% Chelex 100) and stored in 20% glycerol at −80° C. Protein purity and concentration were determined by SDS-PAGE followed by staining with SYPRO Ruby (Invitrogen).Kinase assays were conducted using a peptide-based ELISA based on the syntide-2 peptide (Calbiochem). Syntide-2 peptide (10 mg/ml) was used to coat 96-well plates by overnight incubation in carbonate coating buffer (pH 9.6) at 4° C. Following washing in Tris tween (50 mM Tris-HCl, pH 7.5, 0.2% Tween20), plates were blocked with 3% BSA in Tris-tween for 2 h at room temperature, and further washing steps were conducted with Tris-tween. Kinase reactions were conducted at 30° C. for 20 min in kinase buffer (20 mM HEPES, pH 7.5, 10 mM MgCl2, 1 mM DTT, 2.5 mM CaCl2, 0.1 mM EGTA, 0.005% Tween20) containing appropriate amounts of ATP (Km for each enzyme) and enzyme dilutions (see below). Phosphorylated syntide peptides were detected with mAb MS-6E6 (MBL Intl. Corp.), followed by peroxidase-conjugated goat-anti-mouse IgG, developed with the substrate 3,3′,5,5′-Tetramethylbenzidine (TMB) and detected by absorbance at 450 nm. The activity of human calmodulin dependent kinase II alpha (aCaMKII) was tested using the CaM Kinase II Assay CycLex kit (MBL Intl. Corp.).
- In Vitro DGAT2 Assay For determination of IC50 values, the reactions were carried out in 384-well white Polyplates (Perkin Elmer) in a total volume of 20 μL. To 1 μL of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 μL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 15 minutes. hDGAT2 membrane fractions were diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical; dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock). 10 μL of this enzyme working solution was added to the plates and incubation continued for 2 hours at room temperature. DGAT2 reactions were initiated by the addition of 4 μL of substrates containing 30 μM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 μM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 μL of 1% H3PO4. After the addition of 45 μL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.). Plates were centrifuged at 2,000×g for 1 minute in an Allegra 6R Centrifuge (Beckman Coulter) and then were sealed again with fresh covers before reading in a 1450 Microbeta Wallac Trilux Scintillation Counter (Perkin Elmer). DGAT2 activity was measured by quantifying the generated product [14C]tridecanoylglycerol in the upper organic phase.Background activity obtained using 50 μM of (R)-1-(2-((S)-1-(4-Chloro-1H-pyrazol-1-yl)ethyl)-3H-imidazo[4,5-b]pyridin-5-yl)piperidin-3-yl)(pyrrolidin-1-yl)methanone (WO 2013150416, Example 196-A) for complete inhibition of DGAT2 was subtracted from all reactions. Inhibitors were tested at eleven different concentrations to generate IC50 values for each compound. The eleven inhibitor concentrations employed typically included 50, 15.8, 5, 1.58, 0.50, 0.16, 0.05, 0.016, 0.005, 0.0016, and 0.0005 μM. The data were plotted as percentage of inhibition versus inhibitor concentration and fit to the equation, y=100/[1+(x/IC50)z], where IC50 is the inhibitor concentration at 50% inhibition and z is the Hill slope (the slope of the curve at its inflection point).
- In Vitro DGAT2 Assay and Determination of IC50 Values for DGAT2 Inhibitors For determination of IC50 values, the reactions were carried out in 384-well white polypropylene plates (Nunc) in a total volume of 20 μL. To 1 μL of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 μL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 15 minutes. hDGAT2 membrane fractions were diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical; dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock). 10 μL of this enzyme working solution was added to the plates and incubation continued for 2 hours at room temperature. DGAT2 reactions were initiated by the addition of 4 μL of substrates containing 30 μM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 μM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 μL of 1% H3PO4. After the addition of 45 μL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.). Plates were centrifuged at 2,000×g for 1 minute in an Allegra 6R Centrifuge (Beckman Coulter) and then were sealed again with fresh covers before reading in a 1450 Microbeta Wallac Trilux Scintillation Counter (Perkin Elmer). DGAT2 activity was measured by quantifying the generated product [14C]tridecanoylglycerol in the upper organic phase.Background activity obtained using 50 μM of ((R)-1-(2-((S)-1-(4-chloro-1H-pyrazol-1-yl)ethyl)-3H-imidazo[4,5-b]pyridin-5-yl)piperidin-3-yl)(pyrrolidin-1-yl)methanone (WO 2013150416, Example 196-A) for complete inhibition of DGAT2 was subtracted from all reactions. Inhibitors were tested at eleven different concentrations to generate IC50 values for each compound. The eleven inhibitor concentrations employed typically included 50, 15.8, 5, 1.58, 0.50, 0.16, 0.05, 0.016, 0.005, 0.0016, and 0.0005 μM. The data were plotted as percentage of inhibition versus inhibitor concentration and fit to the equation, y=100/[1+(x/IC50)z], where IC50 is the inhibitor concentration at 50% inhibition and z is the Hill slope (the slope of the curve at its inflection point).
- Kinase Assay In a typical assay 11 different concentrations of each compound (0.1 nM, 0.33 nM, 1.1 nM, 3.8 nM, 13 nM, 44 nM, 0.15 μM, 0.51 μM, 1.7 μM, 5.9 μM and 20 μM) were tested in duplicate within the same microtiter plate. To this end, 100-fold concentrated compound solutions (in DMSO) were previously prepared by serial dilution (1:3.4) of 2 mM stocks in a clear low volume 384-well source microtiter plate (Greiner Bio-One, Frickenhausen, Germany), from which 50 nl of compounds were transferred into a black low volume test microtiter plate from the same supplier. Subsequently, 2 μL of Bub1 (the final concentration of Bub1 was adjusted depending on the activity of the enzyme lot in order to be within the linear dynamic range of the assay: typically ˜200 ng/mL were used) in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCl), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1× Complete EDTA-free protease inhibitor mixture (Roche)] were added to the compounds in the test plate and the mixture was incubated for 15 min at 22° C. to allow pre-equilibration of the putative enzyme-inhibitor complexes before the start of the kinase reaction, which was initiated by the addition of 3 μL 1.67-fold concentrated solution (in assay buffer) of adenosine-tri-phosphate (ATP, 10 μM final concentration) and peptide substrate (1 μM final concentration). The resulting mixture (5 μL final volume) was incubated at 22° C. during 60 min., and the reaction was stopped by the addition of 5 μL of an aqueous EDTA-solution (50 mM EDTA, in 100 mM HEPES pH 7.5 and 0.2% (w/v) bovine serum albumin) which also contained the TR-FRET detection reagents (0.2 μM streptavidin-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-002] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no. AD0077, alternatively a Terbium-cryptate-labeled anti-mouse IgG antibody from Cisbio Bioassays can be used]). The stopped reaction mixture was further incubated 1 h at 22° C. in order to allow the formation of complexes between peptides and detection reagents.
- RORa, b, and g Binding Inhibitors His-tagged human RAR-related orphan receptor alpha (hRORa), human RAR-related orphan receptor beta (hRORb), and human RAR-related orphan receptor gamma (hRORg) are used for receptor-ligand competition binding assays to determine Ki values. Typical procedures are provided below.Receptor competition binding assays are run in a buffer made up of DPBS (1 L) (Hyclone #SH30028.03), 2.2 g BSA Fraction v (Roche #9048-46-8), 100 mL glycerol (Fischer #56-81-5) and 40 mL DMSO (reagent grade). The final wells contain 20 μg/mL aprotinin and 20 μg/mL leupeptin and 10 μM Pefabloc. Typically, receptor binding assays include radio-labeled ligands, such as 7 nM [3H]-25-hydroxycholesterol for alpha binding, 20 nM [3H]-3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for beta binding, and 6 nM [3H]-25-hydroxycholesterol for gamma binding, and 0.5 μg RORa receptor, 0.03 μg RORb receptor, or 0.13 μg RORg receptor per well. Assays are typically run in 96-well format. Competing test compounds are added at various concentrations ranging from about 0.4 nM to 25 μM. Non-specific binding is determined in the presence of 250 nM 25-hydroxycholesterol for RORa and RORg binding, 250 nM 3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for RORb binding. The sample, label and receptor solutions are combined in a 96 well assay plate (Costar 3632) and incubated overnight at room temperature, then 25 μl beads (Amersham YSi (2-5 micron) copper His-tag Spa Beads, #RPNQ0096) for a final bead concentration of 1 mg/well is added to each reaction. Plates are mixed for 30 minutes on an orbital shaker at room temperature. After an incubation of 4 hours, plates are read in a Wallac MICROBETA counter.The data are used to calculate an estimated IC50 using a four parameter logistic fit. The Kd for [3H]-25-hydroxycholesterol for RORa and RORg, and [3H]-3-[[4-[[3-(2,6-dichlorophenyl)-5-isopropyl-isoxazol-4-yl]methoxy]-N,2-dimethyl-anilino]methyl]benzoic acid for RORb binding, is determined by saturation binding. The IC50 values for compounds are converted to Ki using the Cheng-Prushoff equation.
- ELISA Assay ROCK Substrate Coated Plate (Part No 241601): One strip well 96-well plate pre-coated with recombinant MYPT1.Buffer: 25 mM Tris, pH 7.5, 10 mM MgCl2, 5 mM Glycerol-2-Phosphate, 0.1 mM Na3VO4; 1% DMSO; 2.5 mM DTT; (Enzyme: ROCK active-II) (Cell Biolabs, Catalog #STA-406, Part No. 241505) 0.1 ng/μl.ATP Solution (Part No. 241604): 100 mM ATP. Final concentration of ATP in reaction mixture: 250 μM.Anti-phospho-MYPT1 (Thr696) (Part No. 241603).Secondary Antibody, HRP Conjugate (Part No. 231003).Biotinylated substrate, diluted to 0.25 μM with buffer described above (without ATP).Steps:1. Purified kinase or cell lysate sample can be used directly in the kinase assay or further diluted with 1× Kinase Buffer. Each sample should be assayed in duplicate.2. Add 90 μL of the diluted active ROCK-II positive control or unknown ROCK samples to the wells of the substrate plate.3. Initiate the kinase reaction by adding 10 μL of the 10× Kinase Reaction Buffer containing DTT and ATP. Mix well.4. Cover with a plate cover and incubate the wells at 30° C. for 30-60 minutes with gentle agitation.5. Stop kinase reaction by flicking out the content or by adding 50 μL of 0.5M EDTA, pH 8.0, to each well.6. Remove the plate cover and empty wells. Wash microwell strips 3 times with 250 μL 1× Wash Buffer per well with thorough aspiration between each wash. After the last wash, empty wells and tap microwell strips on absorbent pad or paper towel to remove excess 1× Wash Buffer.7. Add 100 μL of the diluted anti-phospho-MYPT1 (Thr696) antibody to each well.8. Cover with the plate cover and incubate at room temperature for 1 hour on an orbital shaker.9. Remove the plate cover and empty wells. Wash the strip wells 3 times according to step 6 above.10. Add 100 μL of the diluted HRP-conjugated secondary antibody to each well.11. Cover with the plate cover and incubate at room temperature for 1 hour on an orbital shaker.12. Remove the plate cover and empty wells. Wash microwell strips 3 times according to step 6 above. Proceed immediately to the next step.13. Warm Substrate Solution to room temperature. Add 100 μL of Substrate Solution to each well, including the blank wells. Incubate at room temperature for 5-20 minutes on an orbital shaker.14. Stop the enzyme reaction by adding 100 μL of Stop Solution into each well, including the blank wells. Results should be read immediately (color will fade over time).15. Read absorbance of each microwell on a spectrophotometer using 450 nm as the primary wave length.
- Omnia Assay Protocol for Potency Assessment Against (method b) MDA-MB-453 and Huh7 cells were grown in 96-well poly-D-lysine plates (BD Bioscience, San Jose, Calif.) to 90% confluence. The cells were then incubated in low-serum (0.1% FBS) media for 16-18 hr. and then treated with 5, 1.67, 0.56, 0.185, 0.068, 0.021 or 0.007 μM of test compound in low-serum (0.1% FBS) media for 1 hr. After treatment, the cells were washed with cold PBS (Invitrogen), and were immediately lysed by freeze/thawing 3× in 32 μL of cold Cell Extraction Buffer (Invitrogen), which was supplemented with Complete Protease inhibitors (Roche) and PhosphoSTOP (Roche) phosphatase inhibitors.MSD plates (Meso Scale Discovery) were coated with total FGFR-4 antibodies overnight at 4° C. A lysate (25 μL) was added to the MSD plate overnight at 4° C. The MSD signals were obtained by incubating with a phospho-FGFR antiobody (R&D Systems) and an anti-rabbit sulfo-tag antibody (Meso Scale), for 2 hr at room temperature. The results are indicated as % DMSO control. The data was fitted using a sigmoidal curve analysis program (Graph Pad Prism version 5) with variable Hill slope to determine the EC50 values.Alternatively, a 10× stock solution of FGFR4-WT (F01-11G), (SignalChem, Richmond, BC) corresponding to method b in Table 7, was prepared as described below. A solution of 1.4×ATP (AS001A) and 5× Tyr-Sox conjugated peptide substrate (KNZ3101) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of FGFR4 was pipetted into a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.), containing a 0.5 μL volume of 100% DMSO. The serially diluted compounds were prepared on a Tecan EV0100. A second addition of 10 μl of Tyr-Sox FGFR4 substrate was added to each well and the kinase reactions were started with the addition of 35 μL of 1.4×ATP. The reactions were monitored every 71 seconds for 240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜60 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (seconds) and then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response (Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.)).
- In Vitro DGAT2 Assay For determination of IC50 values, the reactions were carried out in 384-well white Polyplates (Perkin Elmer) in a total volume of 20 μL. To 14 of compounds dissolved in 100% DMSO and spotted at the bottom of each well, 5 μL of 0.04% bovine serum albumin (BSA) (fatty acid free, Sigma Aldrich) was added and the mixture was incubated at room temperature for 20 minutes. To this mixture, 10 μL of hDGAT2 membrane fraction (0.01 mg/mL) diluted in 100 mM Hepes-NaOH, pH 7.4, 20 mM MgCl2 containing 200 nM methyl arachidonyl fluorophosphonate (Cayman Chemical; dried from ethyl acetate stock solution under argon gas and dissolved in DMSO as 5 mM stock) was added. After this mixture was preincubated at room temperature for 2 hours, DGAT2 reactions were initiated by the addition of 4 μL of substrates containing 30 μM [1-14C]decanoyl-CoA (custom-synthesized by Perkin Elmer, 50 mCi/mmol) and 125 μM 1,2-didecanoyl-sn-glycerol (Avanti Polar Lipids) dissolved in 12.5% acetone. The reaction mixtures were incubated at room temperature for 40 min and the reactions were stopped by addition of 5 μL of 1% H3PO4. After the addition of 45 μL MicroScint-E (Perkin-Elmer), plates were sealed with Top Seal-A covers (Perkin-Elmer) and phase partitioning of substrates and products was achieved using a HT-91100 microplate orbital shaker (Big Bear Automation, Santa Clara, Calif.). Plates were centrifuged at 2,000×g for 1 min in an Allegra 6R Centrifuge (Beckman Coulter) and then were sealed again with fresh covers before reading in a 1450 Microbeta Wallac Trilux Scintillation Counter (Perkin Elmer). DGAT2 activity was measured by quantifying the generated product [14C]tridecanoylglycerol in the upper organic phase. Background activity obtained using 50 μM of (1R, 2R)-2-({3′-Fluoro-4′-[(6-fluoro-1, 3-benzothiazol-2-yl)amino]-1,1′-biphenyl-4-yl}carbonyl)cyclopentanecarboxylic acid (US 20040224997, Example 26) or (R)-1-(2-((S)-1-(4-Chloro-1H-pyrazol-1-yl)ethyl)-3H-imidazo[4,5-b]pyridin-5-yl)piperidin-3-yl)(pyrrolidin-1-yl)methanone (WO 2013150416, Example 196-A) for complete inhibition of DGAT2 was subtracted from all reactions. Inhibitors were tested at eleven different concentrations to generate IC50 values for each compound. The eleven inhibitor concentrations employed typically included 50, 15.8, 5, 1.58, 0.50, 0.16, 0.05, 0.016, 0.005, 0.0016, and 0.0005 μM. The data were plotted as percentage of inhibition versus inhibitor concentration and fit to the equation, y=100/[1+(x/IC50)z], where IC50 is the inhibitor concentration at 50% inhibition and z is the Hill slope (the slope of the curve at its inflection point). Table 3 below provides the IC50 values of the Examples for inhibition of DGAT2 in accordance with the above-described assay. Results are reported as geometric mean IC50 values.
- Omnia Assay Protocol for Potency Assessment Against (method a) For MDA-MB-453 cells signaling, cells were grown in 96-well poly-D-lysine plates (BD Bioscience, San Jose, Calif.) to 90% confluence, and were then incubated in low-serum (0.1% FBS) media for 16-18 hr. The cells were then treated with 5, 1.25, 0.31, 0.078, 0.020 or 0.005 μM of test compound in low-serum (0.1% FBS) media for 1 hr. After treatment, the cells were washed with cold PBS (Invitrogen) and were immediately lysed by freeze/thawing 3×in 32 μL of cold Cell Extraction Buffer (Invitrogen) which was supplemented with Complete Protease inhibitors (Roche, Indianapolis, Ind.) and PhosphoSTOP (Roche) phosphatase inhibitors.The MDA-MB-453 protein concentrations were determined by a BCA Assay (Pierce, Rockford, Ill.). A sample of 50-100 μg of each lysate was separated by a 4-12% gradient (SDS-PAGE (Invitrogen)), transferred to a nitrocellulose membrane (Biorad, Hercules, Calif.), and probed with specific antibodies. Phospho-protein signals were quantitated using Odyssey Infrared Imaging (Li-Cor Biosciences).To assess phospho-FGFR signaling, the blots were probed with anti-Phospho-FGFR (Y653/Y654) and total anti-FGFR antibodies. The phospho-FGFR signal was normalized to total FGFR expression for each sample. The results are indicated as % DMSO control. The normalized data was fitted using a sigmoidal curve analysis program (Graph Pad Prism version 5) with variable Hill slope to determine the EC50 values.Alternatively, a 10× stock solution of FGFR4-WT (F01-11G), (SignalChem, Richmond, BC) corresponding to method b in Table 7, was prepared as described below. A solution of 1.4×ATP (AS001A) and 5× Tyr-Sox conjugated peptide substrate (KNZ3101) were prepared in 1× kinase reaction buffer consisting of 20 mM Tris, pH 7.5, 5 mM MgCl2, 1 mM EGTA, 5 mM β-glycerophosphate, 5% glycerol (10× stock, KB002A) and 0.2 mM DTT (DS001A). 5 μL of FGFR4 was pipetted into a Corning (#3574) 384-well, white, non-binding surface microtiter plate (Corning, N.Y.), containing a 0.5 μL volume of 100% DMSO. The serially diluted compounds were prepared on a Tecan EV0100. A second addition of 10 μl of Tyr-Sox FGFR4 substrate was added to each well and the kinase reactions were started with the addition of 35 μL of 1.4×ATP. The reactions were monitored every 71 seconds for 240 minutes at λex360/λem485 in a Synergy plate reader from BioTek (Winooski, Vt.). At the conclusion of each assay, progress curves from each well were examined for linear reaction kinetics and fit statistics (R2, 95% confidence interval, absolute sum of squares). Initial velocity (0 minutes to ˜60 minutes) from each reaction was determined from the slope of a plot of relative fluorescence units vs time (seconds) and then plotted against inhibitor concentration to estimate IC50 from log[Inhibitor] vs Response (Variable Slope model in GraphPad Prism from GraphPad Software (San Diego, Calif.)).
- ER Transcription Assay (MCF7 Cells) The ER transcription assay is a reporter assay that is based on the ability of ER to induce transcription from a luciferase reporter gene containing estrogen response elements (EREs) in the promoter/enhancer region. When the reporter gene is transfected in MCF7 cells (containing endogenous ER), transcription is reflected by the level of luciferase expression.MCF7 cells are maintained in DMEM/F12 (Gibco, catalog number 11330) supplemented with 10% fetal bovine serum (FBS) (Gemini Bio-Products, catalog number 100-106). A day before transfection, cells are split into a T75 flask at a cell density of 300,000 cells/mL (10 mL total) and allowed to attach overnight in a humidified CO2 incubator at 37° C.Next day, prior to transfection, media is switched to DMEM/F12 (Gibco, catalog number 21041) supplemented with 10% charcoal-stripped serum (Gemini Bio-Products, catalog number 100-119). MCF7 cells are then bulk transfected, using Lipofectin (Invitrogen, catalog number 18292) with the following plasmids: 7x-TK-ERE-Luc3 (ER reporter gene) and pCMV-Renilla (normalization control). Briefly, for each T75 flask, 32.5 μL of Lipofectin is added to 617.5 μL of OptiMEM (Gibco #11058) and incubated for 30 min at 37 C. Approximately 20 ug DNA is mixed in OptiMEM (Invitrogen) to a total volume of 650 μL. Following incubation, the OptiMEM-DNA mixture is added to the OptiMEM-Lipofectin mix and incubated for 15 minutes at 37° C. The DNA-Lipofectin mixture is then added directly to the T75 flask and the flask is returned to the incubator.After overnight incubation, compound is added to individual wells of a 96-well plate in a 10 μL volume of media at 10× concentration along with 1713 estradiol whose final concentration is 0.1 nM. Normally, DMSO (used as a vehicle) is included to achieve a final concentration of 0.1% when added to the cells. Transfected cells are trypsinized, resuspended in DMEM/F12/10% charcoal-stripped serum and added to the 96-well plate at 25,000 cells/well in 90 μL of media. The plate is then returned to the incubator for 24 hours.After incubation with compounds for 24 hours, Firefly and Renilla luciferase activities are measured to determine ER transcriptional activity. Media is removed from 96-well plates by decanting and blotting on paper towels. Cells are lysed with 40 ul/well of 1× passive lysis buffer (25 mM Tris Phosphate, 2 mM CDTA, 10% Glycerol, 0.5% Triton X-100 and 2 mM DTT before use) and allowed incubate at room temperature for 10 minutes.Firefly luciferase activity is measured by adding 30 ul Firefly luciferase assay buffer (20 mM Tricine, 0.1 mM EDTA, 1.07 mM (MgCO3)4 Mg(OH)2*5H2O, 2.67 mM MgSO4, 33.3 mM DTT, 270 μM Coenzyme A, 470 μM luciferin, 530 μM ATP, reconstituted) per well, followed by measuring light units using a luminometer (BMG labtech FLUOstar OPTIMA). One second total read time after a one second delay.Renilla luciferase activity is measured by adding 50 ul Renilla luciferase assay buffer (1.1M NaCl, 2.2 mM Na2EDTA, 0.22 M KxPO4 (pH 5.1), 0.44 mg/mL BSA, 1.3 mM NaN3, 1.43 uM coelenterazine, final pH adjusted to 5.0), per well, followed by measuring light units using a luminometer. One second total read time after one second delay. If Firefly luciferase signal is high, Renilla assay must be done an hour after the Firefly assay due to incomplete squelching of Firefly signal.
- In Vitro Assays for IDH1m (R132H or R132C) Inhibitors In the primary reaction, the reduction of α-KG acid to 2-HG is accompanied by a concomitant oxidation of NADPH to NADP. The amount of NADPH remaining at the end of the reaction time is measured in a secondary diaphorase/resazurin reaction in which the NADPH is consumed in a 1:1 molar ratio with the conversion of resazurin to the highly fluorescent resorufin. Uninhibited reactions exhibit a low fluorescence at the end of the assay, while reactions in which the consumption of NADPH by R132H IDH1 has been inhibited by a small molecule show a high fluorescence.The primary reaction is performed in a volume of 50 μL 1× Buffer (150 mM NaCl, 20 mM Tris 7.5, 10 mM MgCl2, 0.05% (w/v) bovine serum albumin), contained 0.25 ug/mL (2.7 nM) IDH1 wt/IDH1 R132H heterodimer, 0.3 mM alpha-ketoglutarate, 4 μM NADPH, and either 300 μM NADP (saturated) or 30 μM NADP (without saturation), and 1 uL of 50× compound in DMSO. The mixture of compound, enzyme, and cofactor is pre-incubated at room temperature for 1 hr prior to the addition of alpha-ketoglutarate. To perform the secondary reaction, 10 uL of 1× buffer containing 36 μg/ml diaphorase and 30 mM resazurin is added to the primary reaction and incubated for a further 5 minutes at 25° C. Florescence is read on a Spectramax platereader at Ex 544 Em 590. Compounds or compound dilutions are prepared in 100% DMSO concentration and diluted 1:50 into the final reaction. IDH1 wt/IDH1 R132C is assayed under similar conditions except that 1× Buffer is 50 mM K2HP04, pH 6.5; 10 mM MgCl2; 10% glycerol; 0.03% (w/v) bovine serum albumin and final concentrations are 0.4 ug/mL (4.3 nM) IDH1 wt/IDH1 R132C heterodimer, 0.02 mM alpha-ketoglutarate, 4 uM NADPH, and either 300 μM NADP (saturated) or 30 μM NADP (without saturation). IC50s are determined.IDH1 or IDH2 wildtype (wt) and mutant heterodimers are expressed and purified by methods known in the art. For example, IDH1wt/R132m heterodimer is expressed and purified as follows. Co-expression of IDH1wt-his and IDH1R132C-flag is carried out in sf9 insect cells. Cells (25 g) are resuspended in 250 ml of 50 mM Tirs, 500 mM NaCl, pH7.4, at 4° C. with stirring. Cells are disrupted with 4 passes through an M-Y110 Micro fluidizer (Microfluidics) set to 500 psi, and then centrifuged at 22,000 rcf for 20 min at 4° C. The supernatant is harvested and loaded at 15 cm/h on a Histrap FF 5*1 ml column (GE) which is equilibrated with 50 mM Tirs, 500 mM NaCl, pH7.4. Host cell contaminants are removed by washing the column with equilibration buffer followed by equilibration buffer containing 20 mM imidazole and 60 mM imidazole to baseline. IDH1wt-his homodimer and IDH1wt-his/IDH1R132C-flag are eluted by equilibration buffer containing 250 mM imidazole. Fractions eluted by 250 mM imidazole are pooled together and loaded at 15 cm/h onto a column pre-packed with 10 ml ANTI-FLAG® M2 Affinity Gel (Sigma), the column is equilibrated with 50 mM Tris, 500 mM NaCl, pH7.4. After washing with equilibration buffer, IDH1wt-his/IDH1R132C-flag heterodimer is eluted by equilibration buffer containing flag peptide (0.2 mg/ml). Aliquots of IDH1wt-his/IDH1R132C-flag are flash frozen in liquid N2 and stored at −80° C. Same conditions are used for the purification of IDH1wt-his/IDH1R132H-flag.
- In Vitro Assays for IDH1m (R132H or R132C) Inhibitors In the primary reaction, the reduction of α-KG acid to 2-HG is accompanied by a concomitant oxidation of NADPH to NADP. The amount of NADPH remaining at the end of the reaction time is measured in a secondary diaphorase/resazurin reaction in which the NADPH is consumed in a 1:1 molar ratio with the conversion of resazurin to the highly fluorescent resorufin. Uninhibited reactions exhibit a low fluorescence at the end of the assay, while reactions in which the consumption of NADPH by R132H IDH1 has been inhibited by a small molecule show a high fluorescence.The primary reaction is performed in a volume of 50 μL 1× Buffer (150 mM NaCl, 20 mM Tris 7.5, 10 mM MgCl2, 0.05% (w/v) bovine serum albumin), contained 0.25 ug/mL (2.7 nM) IDH1 wt/IDH1 R132H heterodimer, 0.3 mM alpha-ketoglutarate, 4 μM NADPH, and either 300 μM NADP (saturated) or 30 μM NADP (without saturation), and 1 uL of 50× compound in DMSO. The mixture of compound, enzyme, and cofactor is pre-incubated at room temperature for 1 hr prior to the addition of alpha-ketoglutarate. To perform the secondary reaction, 10 uL of 1× buffer containing 36 μg/ml diaphorase and 30 mM resazurin is added to the primary reaction and incubated for a further 5 minutes at 25° C. Florescence is read on a Spectramax platereader at Ex 544 Em 590. Compounds or compound dilutions are prepared in 100% DMSO concentration and diluted 1:50 into the final reaction. IDH1 wt/IDH1 R132C is assayed under similar conditions except that 1× Buffer is 50 mM K2HPO4, pH 6.5; 10 mM MgCl2; 10% glycerol; 0.03% (w/v) bovine serum albumin and final concentrations are 0.4 ug/mL (4.3 nM) IDH1 wt/IDH1 R132C heterodimer, 0.02 mM alpha-ketoglutarate, 4 uM NADPH, and either 300 μM NADP (saturated) or 30 μM NADP (without saturation). IC50s are determined.IDH1 or IDH2 wildtype (wt) and mutant heterodimers are expressed and purified by methods known in the art. For example, IDH1wt/R132m heterodimer is expressed and purified as follows. Co-expression of IDH1wt-his and IDH1R132C-flag is carried out in sf9 insect cells. Cells (25 g) are resuspended in 250 ml of 50 mM Tris, 500 mM NaCl, pH7.4, at 4° C. with stirring. Cells are disrupted with 4 passes through an M-Y110 Micro fluidizer (Microfluidics) set to 500 psi, and then centrifuged at 22,000 rcf for 20 min at 4° C. The supernatant is harvested and loaded at 15 cm/h on a Histrap FF 5*1 ml column (GE) which is equilibrated with 50 mM Tris, 500 mM NaCl, pH7.4. Host cell contaminants are removed by washing the column with equilibration buffer followed by equilibration buffer containing 20 mM imidazole and 60 mM imidazole to baseline. IDH1wt-his homodimer and IDH1wt-his/IDH1R132C-flag are eluted by equilibration buffer containing 250 mM imidazole. Fractions eluted by 250 mM imidazole are pooled together and loaded at 15 cm/h onto a column pre-packed with 10 ml ANTI-FLAG® M2 Affinity Gel (Sigma), the column is equilibrated with 50 mM Tris, 500 mM NaCl, pH7.4. After washing with equilibration buffer, IDH1wt-his/IDH1R132C-flag heterodimer is eluted by equilibration buffer containing flag peptide (0.2 mg/ml). Aliquots of IDH1wt-his/IDH1R132C-flag are flash frozen in liquid N2 and stored at −80° C. Same conditions are used for the purification of IDH1wt-his/IDH1R132H-flag.
- In Vitro Assays for IDH1m (R132H or R132C) Inhibitors In the primary reaction, the reduction of α-KG acid to 2-HG is accompanied by a concomitant oxidation of NADPH to NADP. The amount of NADPH remaining at the end of the reaction time is measured in a secondary diaphorase/resazurin reaction in which the NADPH is consumed in a 1:1 molar ratio with the conversion of resazurin to the highly fluorescent resorufin. Uninhibited reactions exhibit a low fluorescence at the end of the assay, while reactions in which the consumption of NADPH by R132H IDH1 has been inhibited by a small molecule show a high fluorescence.The primary reaction is performed in a volume of 50 μL 1× Buffer (150 mM NaCl, 20 mM Tris 7.5, 10 mM MgCl2, 0.05% (w/v) bovine serum albumin), contained 0.25 ug/mL (2.7 nM) IDH1 wt/IDH1 R132H heterodimer, 0.3 mM alpha-ketoglutarate, 4 μM NADPH, and either 300 μM NADP (saturated) or 30 μM NADP (without saturation), and 1 uL of 50× compound in DMSO. The mixture of compound, enzyme, and cofactor is pre-incubated at room temperature for 1 hr prior to the addition of alpha-ketoglutarate. To perform the secondary reaction, 10 uL of 1× buffer containing 36 μg/ml diaphorase and 30 mM resazurin is added to the primary reaction and incubated for a further 5 minutes at 25° C. Florescence is read on a Spectramax platereader at Ex 544 Em 590. Compounds or compound dilutions are prepared in 100% DMSO concentration and diluted 1:50 into the final reaction. IDH1 wt/IDH1 R132C is assayed under similar conditions except that 1X Buffer is 50 mM K2HPO4, pH 6.5; 10 mM MgCl2; 10% glycerol; 0.03% (w/v) bovine serum albumin and final concentrations are 0.4 ug/mL (4.3 nM) IDH1 wt/IDH1 R132C heterodimer, 0.02 mM alpha-ketoglutarate, 4 uM NADPH, and either 300 μM NADP (saturated) or 30 μM NADP (without saturation). IC50s are determined.IDH1 or IDH2 wildtype (wt) and mutant heterodimers are expressed and purified by methods known in the art. For example, IDH1 wt/R132m heterodimer is expressed and purified as follows. Co-expression of IDH1 wt-his and IDH1R132C-flag is carried out in sf9 insect cells. Cells (25 g) are resuspended in 250 ml of 50 mM Tris, 500 mM NaCl, pH7.4, at 4° C. with stirring. Cells are disrupted with 4 passes through an M-Y110 Micro fluidizer (Microfluidics) set to 500 psi, and then centrifuged at 22,000 ref for 20 min at 4° C. The supernatant is harvested and loaded at 15 cm/h on a Histrap FF 5*1 ml column (GE) which is equilibrated with 50 mM Tris, 500 mM NaCl, pH7.4. Host cell contaminants are removed by washing the column with equilibration buffer followed by equilibration buffer containing 20 mM imidazole and 60 mM imidazole to baseline. IDH1 wt-his homodimer and IDH1 wt-his/IDH1R132C-flag are eluted by equilibration buffer containing 250 mM imidazole. Fractions eluted by 250 mM imidazole are pooled together and loaded at 15 cm/h onto a column pre-packed with 10 ml ANTI-FLAG M2 Affinity Gel (Sigma), the column is equilibrated with 50 mM Tris, 500 mM NaCl, pH7.4. After washing with equilibration buffer, IDH1 wt-his/IDH1R132C-flag heterodimer is eluted by equilibration buffer containing flag peptide (0.2 mg/ml). Aliquots of IDH1 wt-his/IDH1R132C-flag are flash frozen in liquid N2 and stored at −80° C. Same conditions are used for the purification of IDH1 wt-his/IDH1R132H-flag.
- High Throughput Screening Assay This screening assay measures TRPC6 (transient receptor potential cation channel, subfamily C, member 6) ion channel activation via addition either of the commercially available DAG ligand analogue OAG (1-oleoyl-2-acetyl-sn-glycerol) or of the TRPC6 agonist 1-[1-(4,5,6,7,8-pentahydrocyclohepta[2,1-d]thiophen-2-ylcarbonyl)-4-piperidyl]-3-hydrobenzimidazol-2-one (GSK1702934A). The assay utilizes a FLIPR fluorescent calcium sensor 4-(6-Acetoxymethoxy-2,7-difluoro-3-oxo-9-xanthenyl)-4′-methyl-2,2′-(ethylenedioxy)dianiline-N,N,N′,N′-tetraacetic acid tetrakis(acetoxymethyl) ester (Fluo4/AM) membrane potential (FMP) dye from Molecular Devices, which is a voltage sensitive indicator with a fluorescent quencher. Changes (increases) in intracellular membrane calcium concentration potential as measured by the fluorescent signal increase during membrane depolarization provide a measurement of channel activity.The commercially available HEK293/TREx line (Invitrogen) was stably transfected with a TRPC6 construct and screened by conventional calcium imaging to find clones with TRPC6 expression following stimulation with 1 μg/ml tetracycline. These cells were maintained in the growth medium recommended by the manufacturer supplemented with 100 μg/ml hygromycin to promote retention of the TRPC6 construct. After growing to near confluency, cells were plated at a density of 35,000 cells/well in 384 well CellBind plates (Corning) in the presence of 1 μg/ml tetracycline, and allowed to grow for 20-30 hrs. A nearly confluent monolayer resulted. Growth media was removed from the wells and cells were then loaded with 25 mL Fluo4/AM diluted in Ringer's Solution (6.5 g NaCl, 0.42 g KCl, 0.25 g CaCl2) and 0.2 g of sodium bicarbonate; pH 7.4) supplemented with 1% Pluronic F-127 to a final concentration of 0.5 μM and incubated for 60 min, at room temperature. Dye solution was then removed from the cells by inverting plates with a sharp flick, and replaced with 25 μl Ringer's. Following ˜0.5 hour for recovery from loading, cells were assayed using the Hamamatsu FDSS 6000 system, which permitted illumination at 485 nm. Frames were acquired at a rate of 0.2 Hz. During the assay, the plates were continuously vortexed, with pipette mixing of wells following addition of each reagent. For the screening assay, 26 μl of a diluted compound stock (at 50 μM) was added to each well for 2 minutes following the collection of a short (4 frame) baseline. 13 μl of agonist solution consisting of 125 nM GSK1702934A diluted in high-Ca2+Ringer solution (containing 90 mm Ca2+) was then added to each well, achieving a final concentration of 20 mm Ca2+ and 10 μM test compound. Data was collected for 3 minutes following addition of high Ca2+Ringer. The fluorescent ratio for each well was divided by the initial fluorescent intensity for that well and the overall response was determined by averaging the fluorescent ratio of the last 4 frames acquired during the experiment excepting the final frame. Negative and Positive controls were included on each plate. Negative controls wells consisted of HEK293/TREx TRPC6 cells exposed to assay buffer and agonist solution, but no test compound. Positive control consisted of wells consisted of HEK293/TREx TRPC6 cells exposed to 25 μM 3-[(2-chlorophenoxy)methyl]phenyl piperidyl ketone (Chembridge) diluted in Ringer's solution and agonist solution. These controls defined zero percent and 100 percent block respectively, and intensity of each well was normalized to these values.IC50s were determined using the above fluorescence method with the exception that instead of testing the compounds at 10 μM, compounds were tested at final concentrations of 20 μM, 6.667 μM, 2.222 μM, 0.741 μM, 0.247 μM, 0.082 μM, and 0.027 μM. Compounds were tested in triplicate at all concentrations. Standard software was used to fit IC50 curves.
- Biochemical Assays iFLiK and HTRF studies were carried out as described in Z. Fang, J. R. Simard, D. Plenker, H. D. Nguyen, T. Phan, P. Wolle, S. Baumeister, D. Rauh, ACS Chem. Biol. 2015, 10, 279-288.All reagents for HTRF experiments were purchased from Cisbio Bioassays, France. OriginPro 9.1G software (OriginLab Corporation, Northhampton, Mass.) was used for data analysis and data was fit to a sigmoidal dose-response model using the following four-parameter logistic equation:y = A 2 + ( A 2 - A 1 ) ( 1 + ( x IC 50 ) p ) ( 1 ) (A1: bottom asymptote; A2: top asymptote; IC50: half-maximal inhibitory concentration; p: Hill coefficient) Kinetic Characterization of Covalent Probe Compounds:Time-dependent IC50 measurements were performed with activated full-length Akt1 as described under Biochemical assays. Briefly, IC50 values were determined for twelve different incubation times and afterwards plotted versus accordingly. Data was analyzed according to literature procedure as described in B. F. Krippendorff, R. Neuhaus, P. Lienau, A. Reichel, W. Huisinga, J. Biomol. Screen. 2009, 14, 913-923. Ki and kinact were calculated with XLfit (Version 5.4.0.8, IDBS, Munich, Germany) defining the substrate concentration as 250 nM and the corresponding substrate KM as 150 nM.Mass Spectrometry:Purified full-length wtAkt1 was thawed under cold water and diluted to a final concentration of 1 mg/mL in storage buffer (50 mM HEPES, 200 mM NaCl, 10% Glycerol, pH 7.4). 20 μL of the respective mixture were mixed with 2 molar equivalents of the compounds of formulas (1a) and (2a), respectively (10 mM in DMSO); samples containing equal volumes of DMSO were individually prepared for control measurements. Following incubation for thirty minutes on ice, the samples were analyzed by ESI-MS using an Agilent 1100 Series HPLC System connected to a ThermoFinnigan LTQ Linear Ion Trap mass spectrometer. Therefore, 6 μL of sample were injected and separated using a Vydac 214TP C4 5 u column (150 mm×2.1 mm) starting at 20% of solvent B for five minutes followed by a gradient up to 90% of solvent B over 14 min (flow rate 210 μL/min) with 0.1% TFA in water as solvent A and 0.1% TFA in acetonitrile as solvent B. After washing the column for two minutes with 90% of solvent B, the concentration of solvent A was increased to 80% in 1 min and the column was washed for five additional minutes. During the complete experiment, a mass range of 700 to 2000 m/z was scanned and raw data was deconvoluted and analyzed with MagTran and mMass (Version 5.5.0) software.For ESI-MS/MS measurements, samples were denatured, separated via SDS-PAGE followed by staining with Coomassie Brilliant Blue and prepared according to standard tryptic in-gel digest protocols as described in A. Shevchenko, H. Tomas, J. Havlis, J. V. Olsen, M. Mann, Nat. Protoc. 2006, 1, 2856-2860. Subsequently, samples were thawed, dissolved in 20 μL of 0.1% TFA in water, sonicated at room temperature for 15 min, and centrifuged at 15000×g for 1 min shortly before analysis. 3 μL of sample were loaded onto a pre-column cartridge and desalted for 5 min using 0.1% TFA in water as eluent at a flow rate of 30 μL/min. The samples were back-flushed from the pre-column to the nano-HPLC column during the whole analysis. Elution was performed using a gradient starting at 5% B with a final composition of 30% B after 35 min (flow rate 300 nL/min) using 0.1% formic acid in water as eluent A and 0.1% formic acid in acetonitrile as eluent B and a column temperature of 40° C. The nano-HPLC column was washed by increasing the percentage of solvent B to 60% in 5 min and to 95% in additional 5 min, washing the columns for further 5 min, flushing back to starting conditions and equilibration of the system for 14 min. During the complete gradient cycle, a typical TOP10 shot-gun proteomics method for the MS and MS/MS analysis was used.
- Bub1 Kinase Assay Bub1-inhibitory activities of compounds described in the present invention were quantified using a time-resolved fluorescence energy transfer (TR-FRET) kinase assay which measures phosphorylation of the synthetic peptide Biotin-Ahx-VLLPKKSFAEPG (SEQ ID No. 1) (C-terminus in amide form), purchased from e.g. Biosyntan (Berlin, Germany) by the (recombinant) catalytic domain of human Bub1 (amino acids 704-1085), expressed in Hi5 insect cells with an N-terminal His6-tag and purified by affinity-(Ni-NTA) and size exclusion chromatography.In a typical assay 11 different concentrations of each compound (0.1 nM, 0.33 nM, 1.1 nM, 3.8 nM, 13 nM, 44 nM, 0.15 μM, 0.51 μM, 1.7 μM, 5.9 μM and 20 μM) were tested in duplicate within the same microtiter plate. To this end, 100-fold concentrated compound solutions (in DMSO) were previously prepared by serial dilution (1:3.4) of 2 mM stocks in a clear low volume 384-well source microtiter plate (Greiner Bio-One, Frickenhausen, Germany), from which 50 nl of compounds were transferred into a black low volume test microtiter plate from the same supplier. Subsequently, 2 μL of Bub1 (the final concentration of Bub1 was adjusted depending on the activity of the enzyme lot in order to be within the linear dynamic range of the assay: typically ˜200 ng/mL were used) in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCl), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1× Complete EDTA-free protease inhibitor mixture (Roche)] were added to the compounds in the test plate and the mixture was incubated for 15 min at 22° C. to allow pre-equilibration of the putative enzyme-inhibitor complexes before the start of the kinase reaction, which was initiated by the addition of 3 μL 1.67-fold concentrated solution (in assay buffer) of adenosine-tri-phosphate (ATP, 10 μM final concentration) and peptide substrate (1 μM final concentration). The resulting mixture (5 μL final volume) was incubated at 22° C. during 60 min. and the reaction w as stopped by the addition of 5 μL of an aqueous EDTA-solution (50 mM EDTA, in 100 mM HEPES pH 7.5 and 0.2% (w/v) bovine serum albumin) which also contained the TR-FRET detection reagents (0.2 μM streptavidin-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-002] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no. AD0077, alternatively a Terbium-cryptate-labeled anti-mouse IgG antibody from Cisbio Bioassays can be used]). The stopped reaction mixture was further incubated 1 h at 22° C. in order to allow the formation of complexes between peptides and detection reagents. Subsequently, the amount of product was evaluated by measurement of the resonance energy transfer from the Eu-chelate-antibody complex recognizing the Phosphoserine residue to the streptavidin-XL665 bound to the biotin moiety of the peptide. To this end, the fluorescence emissions at 620 nm and 665 nm after excitation at 330-350 nm were measured in a TR-FRET plate reader, e.g. a Rubystar or Pherastar (both from BMG Labtechnologies, Offenburg, Germany) or a Viewlux (Perkin-Elmer) and the ratio of the emissions (665 nm/622 nm) was taken as indicator for the amount of phosphorylated substrate. The data were normalised using two sets of control wells for high−(=enzyme reaction without inhibitor=0%=Minimum inhibition) and low−(=all assay components without enzyme=100%=Maximum inhibition) Bub1 activity. IC50 values were calculated by fitting the normalized inhibition data to a 4-parameter logistic equation (Minimum, Maximum, IC50, Hill; Y=Max+(Min−Max)/(1+(X/IC50)Hill)).
- Bub1 Kinase Assay Bub1-inhibitory activities of compounds described in the present invention were quantified using a time-resolved fluorescence energy transfer (TR-FRET) kinase assay which measures phosphorylation of the synthetic peptide Blotin-AhxVLLPKKSFAEPG (C-terminus in amide form), purchased from e.g. Biosyntan (Berlin, Germany) by the (recombinant) catalytic domain of human Bub1 (amino acids 704-1085), expressed in HI5 insect cells with an N-terminal HIs6-tag and purified by affinity-(Ni-NTA) and size exclusion chromatography.In a typical assay 11 different concentrations of each compound (0.1 nM, 0.33 nM, 1.1 nM, 3.8 nM, 13 nM, 44 nM, 0.15 μM, 0.51 μM, 1.7 μM, 5.9 μM and 20 μM) were tested in duplicate within the same microtiter plate. To this end, 100-fold concentrated compound solutions (in DMSO) were previously prepared by serial dilution (1:3.4) of 2 mM stocks in a clear low volume 384-well source microtiter plate (Greiner Bio-One, Frickenhausen, Germany), from which 50 nl of compounds were transferred into a black low volume test microtiter plate from the same supplier. Subsequently, 2 μl of Bub1 (the final concentration of Bub1 was adjusted depending on the activity of the enzyme lot in order to be within the linear dynamic range of the assay: typically ˜200 μg/ml were used) in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCl), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1× Complete EDTA-free protease inhibitor mixture (Roche)] were added to the compounds in the test plate and the mixture was incubated for 15 min at 229 to allow pre-equilibration of the putative enzyme-inhibitor complexes before the start of the kinase reaction, which was initiated by the addition of 3 μl 1.67-fold concentrated solution (in assay buffer) of adenosine-tri-phosphate (ATP, 10 μM final concentration) and peptide substrate (1 μM final concentration). The resulting mixture (5 μl final volume) was incubated at 22° C. during 60 min., and the reaction was stopped by the addition of 5 μl of an aqueous EDTA-solution (50 mM EDTA, in 100 mM HEPES pH 7.5 and 0.2% (w/v) bovine serum albumin) which also contained the TR-FRET detection reagents (0.2 μM streptavidin-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-001] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no. AD0077, alternatively a Terbium-cryptate-labeled anti-mouse IgG antibody from Cisbio Bioassays can be used]). The stopped reaction mixture was further incubated 1 h at 22° C. in order to allow the formation of complexes between peptides and detection reagents. Subsequently, the amount of product was evaluated by measurement of the resonance energy transfer from the Eu-chelate-antlbody complex recognizing the Phosphoserlne residue to the streptavidin-XL665 bound to the biotin moiety of the peptide. To this end, the fluorescence emissions at 620 nm and 665 nm after excitation at 330-350 nm were measured in a TR-FRET plate reader, e.g. a Rubystar or Pherastar (both from BMG Labtechnologies, Offenburg, Germany) or a Viewlux (Perkin-Elmer) and the ratio of the emissions (665 nm/622 nm) was taken as indicator for the amount of phosphorylated substrate. The data were normalised using two sets of (typically 32-) control wells for high-(=enzyme reaction without Inhibitor=0%=Minimum inhibition) and low-(=all assay components without enzyme=100%=Maximum inhibition) Bub1 activity. IC50 values were calculated by fitting the normalized inhibition data to a 4-parameter logistic equation (Minimum, Maximum, IC50, Hill; Y=Max+(Min−Max)/(1+(X/IC50)Hill)) using a Bayer-proprietary analysis software.
- Bub1 kinase assay Bub1-inhibitory activities of compounds described in the present invention were quantified using a time-resolved fluorescence energy transfer (TR-FRET) kinase assay which measures phosphorylation of the synthetic peptide Biotin-Ahx-VLLPKKSFAEPG (SEQ ID No.1) (C-terminus in amide form), purchased from e.g. Biosyntan (Berlin, Germany) by the (recombinant) catalytic domain of human Bub1 (amino acids 704-1085), expressed in Hi5 insect cells with an N-terminal His6-tag and purified by affinity-(Ni-NTA) and size exclusion chromatography.In a typical assay 11 different concentrations of each compound (0.1 nM, 0.33 nM, 1.1 nM, 3.8 nM, 13 nM, 44 nM, 0.15 μM, 0.51 μM, 1.7 μM, 5.9 μM and 20 μM) were tested in duplicate within the same microtiter plate. To this end, 100-fold concentrated compound solutions (in DMSO) were previously prepared by serial dilution (1:3.4) of 2 mM stocks in a clear low volume 384-well source microtiter plate (Greiner Bio-One, Frickenhausen, Germany), from which 50 nl of compounds were transferred into a black low volume test microtiter plate from the same supplier. Subsequently, 2 μL of Bub1 (the final concentration of Bub1 was adjusted depending on the activity of the enzyme lot in order to be within the linear dynamic range of the assay: typically ˜200 ng/mL were used) in aqueous assay buffer [50 mM Tris/HCl pH 7.5, 10 mM magnesium chloride (MgCl2), 200 mM potassium chloride (KCL), 1.0 mM dithiothreitol (DTT), 0.1 mM sodium ortho-vanadate, 1% (v/v) glycerol, 0.01% (w/v) bovine serum albumine (BSA), 0.005% (v/v) Trition X-100 (Sigma), 1× Complete EDTA-free protease inhibitor mixture (Roche)] were added to the compounds in the test plate and the mixture was incubated for 15 min at 22° C. to allow pre-equilibration of the putative enzyme-inhibitor complexes before the start of the kinase reaction, which was initiated by the addition of 3 μL 1.67-fold concentrated solution (in assay buffer) of adenosine-tri-phosphate (ATP, 10 μM final concentration) and peptide substrate (1 μM final concentration). The resulting mixture (5 μL final volume) was incubated at 22° C. during 60 min. and the reaction was stopped by the addition of 5 μL of an aqueous EDTA-solution (50 mM EDTA, in 100 mM HEPES pH 7.5 and 0.2% (w/v) bovine serum albumin) which also contained the TR-FRET detection reagents (0.2 μM streptavidin-XL665 [Cisbio Bioassays, Codolet, France] and 1 nM anti-phosho-Serine antibody [Merck Millipore, cat. #35-002] and 0.4 nM LANCE EU-W1024 labeled anti-mouse IgG antibody [Perkin-Elmer, product no. AD0077, alternatively a Terbium-cryptate-labeled anti-mouse IgG antibody from Cisbio Bioassays can be used]). The stopped reaction mixture was further incubated 1 h at 22° C. in order to allow the formation of complexes between peptides and detection reagents. Subsequently, the amount of product was evaluated by measurement of the resonance energy transfer from the Eu-chelate-antibody complex recognizing the Phosphoserine residue to the streptavidin-XL 665 bound to the biotin moiety of the peptide. To this end, the fluorescence emissions at 620 nm and 665 nm after excitation at 330-350 nm were measured in a TR-FRET plate reader, e.g. a Rubystar or Pherastar (both from BMG Labtechnologies, Offenburg, Germany) or a Viewlux (Perkin-Elmer) and the ratio of the emissions (665 nm/622 nm) was taken as indicator for the amount of phosphorylated substrate. The data were normalised using two sets of control wells for high (=enzyme reaction without inhibitor=0%=Minimum inhibition) and low (=all assay components without enzyme=100%=Maximum inhibition) Bub1 activity. IC50 values were calculated by fitting the normalized inhibition data to a 4-parameter logistic equation (Minimum, Maximum, IC50, Hill; Y=Max+(Min−Max)/(1+(X/IC50)Hill)).
- FRET Activity Assay Determination of a ligand mediated cofactor peptide interaction to quantify ligand binding to the nuclear receptor FXR was performed as follows.Preparation of human FXR alpha ligand binding domain: The human FXRalpha LBD was expressed in E. coli strain BL21(DE3) as an N-terminally GST tagged fusion protein. The DNA encoding the FXR ligand binding domain was cloned into vector pDEST15 (Invitrogen). Expression was under control of an IPTG inducible T7 promoter. The amino acid boundaries of the ligand binding domain were amino acids 187-472 of Database entry NM_005123 (RefSeq). Expression and purification of the FXR-LBD: An overnight preculture of a transformed E. coli strain was diluted 1:20 in LB-Ampicillin medium and grown at 30° C. to an optical density of OD600=0.4-0.6. Gene expression was then induced by addition of 0.5 mM IPTG. Cells were incubated an additional 6 h at 30° C., 180 rpm. Cells were collected by centrifugation (7000×g, 7 min, rt). Per liter of original cell culture, cells were resuspended in 10 mL lysis buffer (50 mM Glucose, 50 mM Tris pH 7.9, 1 mM EDTA and 4 mg/mL lysozyme) and left on ice for 30 min. Cells were then subjected to sonication and cell debris removed via centrifugation (22000×g, 30 min, 4° C.). Per 10 mL of supernatant 0.5 mL prewashed Glutathione 4B sepharose slurry (Qiagen) was added and the suspension kept slowly rotating for 1 h at 4° C. Glutathione 4B sepharose beads were pelleted by centrifugation (2000×g, 15 sec, 4° C.) and washed twice in wash buffer (25 mM Tris, 50 mM KCl, 4 mM MgCl2 and 1M NaCl). The pellet was resuspended in 3 mL elution buffer per liter of original culture (elution buffer: 20 mM Tris, 60 mM KCl, 5 mM MgCl2 and 80 mM glutathione added immediately prior to use as powder). The suspension was left rotating for 15 min at 4° C., the beads pelleted and eluted again with half the volume of elution buffer than the first time. The eluates were pooled and dialysed overnight in 20 mM Hepes buffer (pH 7.5) containing 60 mM KCl, 5 mM MgCl2 as well as 1 mM dithiothreitol and 10% (v/v) glycerol. The protein was analysed by SDS-Page.The method measures the ability of putative ligands to modulate the interaction between the purified bacterial expressed FXR ligand binding domain (LBD) and a synthetic biotinylated peptide based on residues 676-700 of SRC-1 (LCD2, 676-700). The sequence of the peptide used was B-CPSSHSSLTERHKILHRLLQEGSPS-COOH (SEQ ID NO: 1) where the N-terminus was biotinylated (B). The ligand binding domain (LBD) of FXR was expressed as fusion protein with GST in BL-21 cells using the vector pDEST15. Cells were lysed by sonication, and the fusion proteins purified over glutathione sepharose (Pharmacia) according to the manufacturers instructions. For screening of compounds for their influence on the FXR-peptide interaction, the Perkin Elmer LANCE technology was applied. This method relies on the binding dependent energy transfer from a donor to an acceptor fluorophor attached to the binding partner of interest. For ease of handling and reduction of background from compound fluorescence LANCE technology makes use of generic fluorophore labels and time resolved detection Assays were done in a final volume of 25 μL in a 384 well plate, in a Tris-based buffer (20 mM Tris-HCl pH 7.5; 60 mM KCl, 5 mM MgCl2; 35 ng/μL BSA), containing 20-60 ng/well recombinantly expressed FXR-LBD fused to GST, 200-600 nM N-terminally biotinylated peptide, representing SRC1 aminoacids 676-700, 200 ng/well Streptavidin-xlAPC conjugate (Prozyme) and 6-10 ng/well Eu W1024-antiGST (Perkin Elmer). DMSO content of the samples was kept at 1%. After generation of the assay mix and diluting the potentially FXR modulating ligands, the assay was equilibrated for 1 h in the dark at rt in FIA-plates black 384 well (Greiner). The LANCE signal was detected by a Perkin Elmer VICTOR2VTM Multilabel Counter.
- In Vitro Activity Assay The in vitro activity of the compounds of the compounds of the invention may be determined by the following procedure. More particularly, the following assay provides a method to determine whether compounds of the compounds of the invention inhibit the tyrosine kinase activity of the catalytic construct FAK(410-689). The assay is an ELISA-based format, measuring the inhibition of poly-glu-tyr phosphorylation by FAK(410-689). The assay protocol has three parts:I. Purification and cleavage of His-FAK(410-689)II. FAK410-689 (a.k.a. FAKcd) ActivationIII. FAKcd Kinase ELISAMaterials: Ni-NTA agarose (Qiagen) XK-16 column (Amersham-Pharmacia) 300 mM Imidizole Superdex 200 HiLoad 16/60 prep grade column (Amersham Biotech.) Antibody: Anti-Phosphotyrosine HRP-Conjugated Py20 (Transduction labs) FAKcd: Purified and activated in house TMB Microwell Peroxidase Substrate (Oncogene Research Products #CL07) BSA: Sigma #A3294 Tween-20: Sigma #P1379 DMSO: Sigma #D-5879 D-PBS: Gibco #14190-037 Reaqents for Purification: Buffer A: 50 mM HEPES pH 7.0 500 mM NaCl 0.1 mM TCEP Complete protease inhibitor cocktail tablets (Roche) Buffer B: 25 mM HEPES pH 7.0 400 mM NaCl 0.1 mM TCEP Buffer C: 10 mM HEPES pH 7.5 200 mM Ammonium Sulfate 0.1 mM TCEP Reagents for Activation: FAK(410-689): 3 tubes of frozen aliquots at 150 μl/tube for a total of 450 μl at 1.48 mg/ml (660 μg) His-Src(249-524): 0.74 mg/ml stock in 10 mM HEPES, 200 mM (NH4)2SO4 Src reaction buffer (Upstate Biotech): 100 mM Tris-HCl pH7.2 125 mM MgCl2 25 mM MnCl2 2 mM EDTA 250 μM Na3VO4 2 mM DTT Mn2+/ATP cocktail (Upstate Biotech) 75 mM MnCl2 500 μM ATP 20 mM MOPS pH 7.2 1 mM Na3VO4 25 mM glycerol phosphate 5 mM EGTA 1 mM DTT ATP: 150 mM stock MgCl2: 1 M Stock DTT: 1 M stock Reagents for FAKcd Kinase ELISA: Phosphorylation Buffer: 50 mM HEPES, pH 7.5 125 mM NaCl 48 mM MgCl2 Wash Buffer: TBS+0.1% Tween-20. Blocking Buffer: Tris Buffer Saline 3% BSA 0.05% Tween-20, filtered Plate Coating Buffer: 50 mg/ml Poly-Glu-Tyr (Sigma #P0275) in Phosphate buffer Saline (DPBS). ATP: 0.1M ATP in H2O or HEPES, pH7 Note: ATP Assay Buffer: Make up as 75 uM ATP in PBS, so that 80 μl in 120 μl reaction volume=50 μM final ATP concentration. I. Purification of His-FAKcd(410-689): 1. Resuspend 130 g baculovirus cell paste containing the over expressed His-FAKcd410-689 recombinant protein in 3 volumes (400 ml) of Buffer A. 2. Lyse cells with one pass on a microfluidizer. 3. Remove cell debris by centrifugation at 4° C. for 35 minutes at 14,000 rpm in a Sorval SLA-1500 rotor. 4. Transfer the supernatant to a clean tube and add 6.0 ml of Ni-NTA agarose (Qiagen). 5. Incubate the suspension with gentle rocking at 4° C. for 1 hour. 6. Centrifuge suspension at 700×g in a swinging bucket rotor. 7. Discard the supernatant and resuspend the agarose beads in 20.0 ml of Buffer A. 8. Transfer the beads to an XK-16 column (Amersham-Pharmacia) connected to a FPLC. 9. Wash the agarose-beads with 5 column volumes of Buffer A and elute off the column with a step gradient of Buffer A containing 300 mM Imidizole. 10. Perform a buffer exchange of the eluted fractions into Buffer B. 11. Following buffer exchange, pool the fractions and add thrombin at a 1:300 (w/w) ratio and incubated overnight at 13° C. to remove the N-terminal His-tag (His-FAK410-698 à FAK410-689 (a.k.a. FAKcd)). 12. Add the reaction mixture back onto the Ni-NTA column equilibrated with Buffer A and collect the flow-through.
- RET Activity Assay Preparation of human FXR alpha ligand binding domain: The human FXRalpha LBD was expressed in E. coli strain BL21(DE3) as an N-terminally GST tagged fusion protein. The DNA encoding the FXR ligand binding domain was cloned into vector pDEST15 (Invitrogen). Expression was under control of an IPTG inducible T7 promoter. The amino acid boundaries of the ligand binding domain were amino acids 187-472 of Database entry NM_005123 (RefSeq). Expression and purification of the FXR-LBD: An overnight preculture of a transformed E. coli strain was diluted 1:20 in LB-Ampicillin medium and grown at 30° C. to an optical density of OD600=0.4-0.6. Gene expression was then induced by addition of 0.5 mM IPTG. Cells were incubated an additional 6 h at 30° C., 180 rpm. Cells were collected by centrifugation (7000×g, 7 min, rt). Per liter of original cell culture, cells were resuspended in 10 mL lysis buffer (50 mM Glucose, 50 mM Tris pH 7.9, 1 mM EDTA and 4 mg/mL lysozyme) and left on ice for 30 min. Cells were then subjected to sonication and cell debris removed via centrifugation (22000×g, 30 min, 4° C.). Per 10 mL of supernatant 0.5 mL prewashed Glutathione 4B sepharose slurry (Qiagen) was added and the suspension kept slowly rotating for 1 h at 4° C. Glutathione 4B sepharose beads were pelleted by centrifugation (2000×g, 15 sec, 4° C.) and washed twice in wash buffer (25 mM Tris, 50 mM KCl, 4 mM MgCl2 and 1M NaCl). The pellet was resuspended in 3 mL elution buffer per liter of original culture (elution buffer: 20 mM Tris, 60 mM KCl, 5 mM MgCl2 and 80 mM glutathione added immediately prior to use as powder). The suspension was left rotating for 15 min at 4° C., the beads pelleted and eluted again with half the volume of elution buffer than the first time. The eluates were pooled and dialysed overnight in 20 mM Hepes buffer (pH 7.5) containing 60 mM KCl, 5 mM MgCl2 as well as 1 mM dithiothreitol and 10% (v/v) glycerol. The protein was analysed by SDS-Page.The method measures the ability of putative ligands to modulate the interaction between the purified bacterial expressed FXR ligand binding domain (LBD) and a synthetic biotinylated peptide based on residues 676-700 of SRC-1 (LCD2, 676-700). The sequence of the peptide used was B-CPSSHSSLTERHKILHRLLQEGSPS-COOH (SEQ ID NO: 1) where the N-terminus was biotinylated (B). The ligand binding domain (LBD) of FXR was expressed as fusion protein with GST in BL-21 cells using the vector pDEST15. Cells were lysed by sonication, and the fusion proteins purified over glutathione sepharose (Pharmacia) according to the manufacturers instructions. For screening of compounds for their influence on the FXR-peptide interaction, the Perkin Elmer LANCE technology was applied. This method relies on the binding dependent energy transfer from a donor to an acceptor fluorophor attached to the binding partner of interest. For ease of handling and reduction of background from compound fluorescence LANCE technology makes use of generic fluorophore labels and time resolved detection Assays were done in a final volume of 25 μL in a 384 well plate, in a Tris-based buffer (20 mM Tris-HCl pH 7.5; 60 mM KCl, 5 mM MgCl2; 35 ng/μL BSA), containing 20-60 ng/well recombinantly expressed FXR-LBD fused to GST, 200-600 nM N-terminally biotinylated peptide, representing SRC1 aminoacids 676-700, 200 ng/well Streptavidin-xlAPC conjugate (Prozyme) and 6-10 ng/well Eu W1024-antiGST (Perkin Elmer). DMSO content of the samples was kept at 1%. After generation of the assay mix and diluting the potentially FXR modulating ligands, the assay was equilibrated for 1 h in the dark at rt in FIA-plates black 384 well (Greiner). The LANCE signal was detected by a Perkin Elmer VICTOR2V Multilabel Counter. The results were visualized by plotting the ratio between the emitted light at 665 and 615 nm. A basal level of FXR-peptide formation is observed in the absence of added ligand.