Query String: LiCl
lithii chloridum lithium chloride CHEMBL69710 LiCl BDBM50147474 chlorure de lithium cloruro de litio Lithiumchlorid
- ChEMBL_1992277 (CHEMBL4626012) Agonist activity at human GHSR expressed in HEK293 cells assessed as increase in IP1 accumulation measured after 90 mins in presence of LiCl by HTRF assay
- PPlase Assay The assay was conducted at 10° C. in 50 mM Tris buffer at pH8.0, 50 μM DTT, 100 mM NaCl, 0.005% NP40 with 6 nM FKBP12 and 60 μM substrate (SUC-ALPF-pNA, diluted from 20 mg/ml stock in 0.5M LiCl/TFE). The Km for the substrate was determined to be approximately 188 μM. The first order rate equation was fitted to the absorbance data to obtain a rate constant.
- Enzymatic Assay Cyclophilin PPlase activity was measured at 20 C. by using the standard chymotrypsin coupled assay (Kofron J L, Kuzmic P, Kishore V, Colon-Bonilla E, Rich D H. Determination of kinetic constants for peptidyl prolyl cis-trans isomerases by an improved spectrophotometric assay. Biochemistry. 1991 Jun. 25; 30(25):6127-34). The assay buffer (25 mM Hepes, 100 mM NaCl, pH 7.8) and CypA, B or D (1900 nM stock solution) were pre-cooled to 4 C., to which then was added 5 uL of 50 mg/ml chymotrypsin in 1 mM HCl. The reaction was initiated by adding 20 uL of 3.2 mM peptide substrate (Suc-Ala-Ala-cis-Pro-Phe-pNA) in LiCl/TFE solution with rapid inversion. After a delay from the onset of mixing, the absorbance of p-nitroaniline was followed at 390 nM until the reaction was complete (1 min). The final concentration of LiCl in the assay was 20 mM; TFE was present at a concentration of 4% (v/v). Absorbance readings were collected every 1 s by spectrophotometer.
- IPOne assay IP1 accumulation measurements using the IPOne assay system 1321N1 cells stably expressing human GPR40 receptor (Euroscreen, Belgium) are seeded 24 h before the assay in white 384-well plates in culture medium containing 10% FCS, 1% Na-Pyruvate and 400 μg/mL G418. IP1 is assayed according to the manufacturer's description (Cisbio Bioassays, France). In brief, the assay is started by substitution of the culture medium by stimulation buffer (Hepes 10 mM, CaCl2 1 mM, MgCl2 0.5 mM, KCl 4.2 mM, NaCl 146 mM, glucose 5.5 mM and LiCl 50 mM, pH 7.4). Cells are stimulated for 1 h at 37° C., 5% CO2 by addition of the compounds that are diluted in stimulation buffer containing LiCl. Assays are stopped by adding HTRF-conjugates (IP1-d2 and Anti-IP1 cryptate Tb) and lysis buffer, provided by the manufacturer. After an incubation time of 1 h at room temperature plates are measured using an EnVision , Perkin Elmer. The obtained fluorescence ratios at 665/615 nM are then used to calculate the pEC50 values using Assay Explorer 3.3 Software (Accelrys, Inc.) by interpolation using an IP1 reference curve and subsequent sigmoidal curve fitting allowing for a variable hill slope.
- IPOne assay IP1 accumulation measurements using the IPOne assay system 1321N1 cells stably expressing human GPR40 receptor (Euroscreen, Belgium) are seeded 24 h before the assay in white 384-well plates in culture medium containing 10% FCS, 1% Na-Pyruvate and 400 μg/mL G418. IP1 is assayed according to the manufacturer's description (Cisbio Bioassays, France). In brief, the assay is started by substitution of the culture medium by stimulation buffer (Hepes 10 mM, CaCl2) 1 mM, MgCl2 0.5 mM, KCl 4.2 mM, NaCl 146 mM, glucose 5.5 mM and LiCl 50 mM, pH 7.4). Cells are stimulated for 1 h at 37° C., 5% CO2 by addition of the compounds that are diluted in stimulation buffer containing LiCl. Assays are stopped by adding HTRF-conjugates (IP1-d2 and Anti-IP1 cryptate Tb) and lysis buffer, provided by the manufacturer. After an incubation time of 1 h at room temperature plates are measured using an EnVision , Perkin Elmer. The obtained fluorescence ratios at 665/615 nM are then used to calculate the pEC50 values using Assay Explorer 3.3 Software (Accelrys, Inc.) by interpolation using an IP1 reference curve and subsequent sigmoidal curve fitting allowing for a variable hill slope.
- Pharmacological Assay IP1 accumulation measurements using the IPOne assay system 1321N1 cells stably expressing human GPR40 receptor (Euroscreen, Belgium) are seeded 24 h before the assay in white 384-well plates in culture medium containing 10% FCS, 1% Na-Pyruvate and 400 μg/mL G418. IP1 is assayed according to the manufacturer's description (Cisbio Bioassays, France). In brief, the assay is started by substitution of the culture medium by stimulation buffer (Hepes 10 mM, CaCl2 1 mM, MgCl2 0.5 mM, KCl 4.2 mM, NaCl 146 mM, glucose 5.5 mM and LiCl 50 mM, pH 7.4). Cells are stimulated for 1 h at 37° C., 5% CO2 by addition of the compounds that are diluted in stimulation buffer containing LiCl. Assays are stopped by adding HTRF-conjugates (IP1-d2 and Anti-IP1 cryptate Tb) and lysis buffer, provided by the manufacturer. After an incubation time of 1 h at room temperature plates are measured using an EnVision, Perkin Elmer. The obtained fluorescence ratios at 665/615 nM are then used to calculate the pEC50 values using Assay Explorer 3.3 Software (Accelrys, Inc.) by interpolation using an IP1 reference curve and subsequent sigmoidal curve fitting allowing for a variable hill slope.
- IP-One HTRF Assay Inositol monophosphate (IP1) production were measured in 1321N1 cells stably expressing human PAR2 using an IP-One HTRF assay kit (Cisbio). 80 nl of compound in 100% DMSO were added in white small-volume 384-well plates using an Echo 555 (Labcyte) and were incubate for 30 min at 37° C. with 4 μl of cells (15,000 cells per well) in stimulation buffer (HBSS with 20 mM HEPES, pH 7.4). IP1 production was initiated by addition of 4 μl of 140 μM SLIGRL-NH2 (SEQ ID NO.: 4) in stimulation buffer supplemented with 100 mM LiCl. After 60 min at 37° C. cells were lysed and IP1 concentrations were detected according to the manufacturers protocol (Cisbio). Data were normalized to IP1 concentrations using a IP1 standard curve according to the manufacturers protocol (Cisbio).
- Inhibition Assay The PPlase activity of recombinant CypA or D, produced by thrombin cleavage of GST-CypA or D, was determined by following the rate of hydrolysis of N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide by chymotrypsin. Chymotrypsin only hydrolyzes the trans form of the peptide, and hydrolysis of the cis form, the concentration of which is maximized by using a stock dissolved in trifluoroethanol containing 470 mM LiCl, is limited by the rate of cis-trans isomerization. CypA or D was equilibrated for 1 h at 5° C. with selected test article using a drug concentration range from 0.1 to 20 nM. The reaction was started by addition of the peptide, and the change in absorbance was monitored spectrophotometrically at 10 data points per second. The blank rates of hydrolysis (in the absence of CypA or D) were subtracted from the rates in the presence of CypA or D.
- GPR142 Agonist Effect as Measured by IP-1 Assay HEK293 cells expressing human GPR142 are maintained in DMEM supplemented with 10% FBS and 800 μg/ml G418 (Geneticin) at 37° C. and 5% CO2. The cells are plated in 384 well plates at 5000 cells per well and allowed 18 hours for attachment. After addition of compounds at varying concentrations ranging from 30 μM to 1 nM, cells are incubated for 1 hr. IP-1 measurements are performed using an IP-One HTRF assay kit (Cisbio) according to manufacturer's protocol using assay buffer containing 1×HBSS (+Ca, +Mg), 0.1% BSA, 50 mM LiCl and 20 mM HEPES, pH 7.2. The reaction is stopped by addition of IP1-d2 (IP-1 coupled to an organic HTRF acceptor) followed by cryptate solution (http://www.htrf.com/usa/htrf-chemistry). The plates are incubated at 25° C. for 1 hr. Fluorescence is read in an Envision instrument at 665 nm and 620 nm wavelength. The ratio of 665 nm/620 nm is calculated and converted to IP-1 levels using an IP-1 standard curve. The data is fit to a 4 parameter-fit logistics to determine EC50 values.
- 5-HT2B Agonist Activity Assay Evaluation of the agonist activity of compounds (I), (Ia) and (Ib) at the human 5-HT2B receptor was performed by Eurofins/Cerep (France) measuring the compound effects on inositol monophosphate (IP1) production using the HTRF detection method. Briefly, the human 5-HT2B receptor was expressed in transfected CHO cells. The cells were suspended in a buffer containing 10 mM Hepes/NaOH (pH 7.4), 4.2 mM KCl, 146 mM NaCl, 1 mM CaCl2, 0.5 mM MgCl2, 5.5 mM glucose and 50 mM LiCl, then distributed in microplates at a density of 4100 cells/well and incubated for 30 min at 37° C. in the presence of buffer (basal control), test compound or reference agonist. For stimulated control measurement, separate assay wells contained 1 μM 5-HT. Following incubation, the cells were lysed and the fluorescence acceptor (fluorophen D2-labeled IP1) and fluorescence donor (anti-IP1 antibody labeled with europium cryptate) were added. After 60 min at room temperature, the fluorescence transfer was measured at lambda(Ex) 337 nm and lambda(Em) 620 and 665 nm using a microplate reader (Rubystar, BMG). The IP1 concentration was determined by dividing the signal measured at 665 nm by that measured at 620 nm (ratio). The results were expressed as a percent of the control response to 1 μM 5-HT. The standard reference agonist was 5-HT, which was tested in each experiment at several concentrations to generate a concentration-response curve from which its EC50 value is calculated as described above for dopamine functional assays.
- 5-HT2B Agonist Activity Assay Evaluation of the agonist activity of compounds (I), (Ia), (Ib), (Ic), (Ia-iab), compound (2), compound (9), compound (15), compound (27), A2, A3, and A7 at the human 5-HT2B receptor was performed by Eurofins/Cerep (France) measuring the compound effects on inositol monophosphate (IP1) production using the HTRF detection method. Briefly, the human 5-HT2B receptor was expressed in transfected CHO cells. The cells were suspended in a buffer containing 10 mM Hepes/NaOH (pH 7.4), 4.2 mM KCl, 146 mM NaCl, 1 mM CaCl2, 0.5 mM MgCl2, 5.5 mM glucose and 50 mM LiCl, then distributed in microplates at a density of 4100 cells/well and incubated for 30 minutes at 37° C. in the presence of buffer (basal control), test compound or reference agonist. For stimulated control measurement, separate assay wells contained 1 μM 5-HT. Following incubation, the cells were lysed and the fluorescence acceptor (fluorophen D2-labeled IP1) and fluorescence donor (anti-IP1 antibody labeled with europium cryptate) were added. After 60 minutes at room temperature, the fluorescence transfer was measured at lambda(Ex) 337 nm and lambda(Em) 620 and 665 nm using a microplate reader (Rubystar, BMG). The IP1 concentration was determined by dividing the signal measured at 665 nm by that measured at 620 nm (ratio). The results were expressed as a percent of the control response to 1 μM 5-HT. The standard reference agonist was 5-HT, which was tested in each experiment at several concentrations to generate a concentration-response curve from which its EC50 value is calculated as described above for dopamine functional assays.
- Inositol Phosphate Turnover (IP1) Assay 1 The assay was performed in 96-well format. HEK cells stably expressing human GPR40 were plated to be 60-80% confluent within 72 h. After 72 h, the plates were aspirated and the cells washed with inositol-free DMEM (ICN). The wash media was replaced with 150 μL of 3H-inositol labeling media (inositol-free media containing 0.4% human albumin or 0.4% mouse albumin, 1× pen/strep antibiotics, glutamine, 25 mM HEPES to which was added 3H-myo-inositol NEN #NET114A 1 mCi/mL, 25 Ci/mmol diluted 1:150 in loading media with a final specific radioactivity of 1 μCi/150 μL). Alternatively, the human and mouse albumin can be added after the overnight labeling step before the addition of LiCl.The assay was typically run the next day after 18 h labeling. On the day of the assay, 5 μL of 300 mM LiCl was added to all wells and incubated at 37 degrees for 20 min. 0.75 μL of each compound was added and incubated with the cells for 60 min at 37 degrees. The media was then aspirated off and the assay terminated with the addition of 60 μL 10 mM formic acid. The cells were lysed for 60 min at room temperature. 15-30 μL of lysate was mixed with 70 μL/1 mg YSi SPA beads (Amersham) in clear bottom Isoplates. The plates were shaken for 2 h at room temperature. Beads were allowed to settle and the plates were counted in the Wallac Microbeta.
- 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.