| Assay Method Information | |
| | FRET Assay |
| Description: | An HDM2 FRET assay was developed to assess the compounds' inhibitory activity towards binding of p53 protein. A truncated version of HDM2 with residues 17 to 125 (containing p53 binding surface, Science (1994) 265, 346-355), with N-terminal His and Thioredoxin tag was generated in pET32a expression vector and expressed in E. coli strain BL21(DE3)Rosetta. Protein was purified using Ni-affinity chromatography, followed by size exclusion chromatography using Superdex 75 26/60 column. To assess inhibition of p53 binding to HDM2, a FITC labeled 8-mer peptide (sequence: Ac-Phe-Arg-Dpr-Ac6c-(6-Br)Trp-Glu-Glu-Leu-NH2; Anal Biochem. 2004 Aug. 1; 331(1):138-46) with strong affinity towards p53 binding pocket of HDM2 was used. The HDM2 assay buffer contained 1× Phosphate Buffered Saline (Invitrogen, Cat#14190), 0.01% BSA (Jackson ImmunoResearch, Cat#001-000-162), 0.01% Tween-20. In the 1× assay buffer recombinant HDM2 protein, peptide and Lumi4-Tb Cryptate-conjugate mouse anti-6×His antibody (cisbio, Cat# Tb61HISTLB) were added and transferred to ProxiPlate PLUS (PerkinElmer, Cat#6008269), containing compounds so that final DMSO concentration is 0.1%. Final concentrations of reagents in the assay wells are 0.5 nM HDM2, 0.25 nM anti HIS (Tb label) antibody and 3 nM peptide. After two hour incubation at room temperature in a humidified chamber plates were read on EnVision plate reader with the following settings: excitation: UV, 340 nM, two emission filters: 520 nm and 495 nm respectively. Ratio of em520/em495 was used to calculate % inhibition and to obtain IC50 with 4-parameter logistic equation. |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |