CHEMBL5735347

Biochemical Assay: IDH1 mutant (R132H and R132C) and IDH2 mutant (R140Q and R172K) proteins containing N-terminal His-tag are expressed in E. coli and purified using nickel affinity chromatography by methods commonly used and well known to those skilled in the art. The enzyme assays are carried out in V-bottom 96 well polypropylene plates containing 100 mM Tris-HCl buffer, 1 mM DTT, 0.005% TRITON™ X-100, 120 mM NaCl. For IDH1 R132H, α-ketoglutarate, NADPH and MnCl2 are included at final concentrations of 300 μM, 2.5 μM and 300 μM respectively. For IDH1 R132C, α-ketoglutarate, NADPH and MnCl2 are included at final concentrations of 100 μM, 10 μM and 100 μM respectively. For IDH2 R172K, α-ketoglutarate, NADPH, and MnCl2 are included at final concentrations of 150 μM, 10 μM and 150 μM respectively. For IDH2 R140Q, α-ketoglutarate, NADPH, and MnCl2 are included at final concentrations of 300 μM, 10 μM, and 100 μM respectively. Final pH=7.0. Test compound, dissolved in DMSO stock, is diluted in the reaction mixture at a final DMSO concentration of 4%. Compounds are tested in dose-response format. The assay is started by addition of enzyme. Enzymes are used at the following final concentrations: IDH1 R132H, 2 nM; IDH1 R132C, 0.5 nM; IDH2 R172K, 1.2 nM; IDH2 R140Q, 1.2 nM and the assay is allowed to continue for the following times: 40 minutes for IDH-1R132C, 60 minutes for IDH-1HR132H and 50 minutes for the IDH-2172K and IDH-2R140Q enzymes. The reaction is quenched by adding ACN (50:50) containing d5-3HG as an internal standard for mass spectrometry analysis and quantitation of reaction product.