CHEMBL5731200

Inhibitory Activity Against IDH1R132H and IDH1R132C Enzymes: The IDH1R132H protein and the IDH1R132C protein were prepared as follows: the IDH1R132H or IDH1R132C gene was integrated into a pET24b(+) vector (Novagen) to prepare a construct for C-terminal fusion of 6× histidine tag. After transformation of Rosetta 2 (DE3) E. coli, the expression of the protein was induced with IPTG. The E. coli was collected and homogenized, followed by the affinity purification of the 6× histidine fusion protein using HisTrap HP columns (GE Healthcare Japan Corp.) and gel filtration purification using Superdex 200 columns (GE Healthcare Japan Corp.) to obtain the IDH1R132H or IDH1R132C protein of interest.IDH1R132H and IDH1R132C each convert 2-oxoglutarate and NADPH to D-2-hydroxyglutarate (2-HG) and NADP+. Therefore, the activity of the IDH1R132H and IDH1R132C enzymes can be measured by detecting NADPH levels.The enzyme inhibitory activity evaluation was carried out as follows: 40 μL each of reaction solutions containing different concentrations of each compound (100 mM Tris-HCl (pH 7.5), 150 mM NaCl, 20 mM MgCl2, 0.5 mg/mL bovine serum albumin, 1 mM reduced glutathione, 40 μM NADPH, 0.5 mM 2-oxoglutarate, 0.5% dimethyl sulfoxide, 50000 to 0.128 nM compound, and 12 nM IDH1R132H or 10 nM IDH1R132C as the enzyme) was added to each well of 384-well plates (Greiner Bio One International GmbH, #781096) and incubated at room temperature. While NADPH-derived fluorescence was occasionally monitored, the reaction was terminated by the addition of 5 μL of 0.5 M EDTA before consumption of NADPH. 5 μL of WST-8 reagent (Dojindo Laboratories, #CK04) was further added and mixed therewith. 15 minutes later, the absorbance at 450 nm was measured using a plate reader (PerkinElmer, Inc., EnVision). The observed absorbance value reflects the amount of residual NADPH. From the absorbance data, the enzyme inhibitory activity of each compound at each concentration was calculated and analyzed using medical statistical analysis software GraphPad Prism to calculate an IC50 value.