Fig. 4: NMR biophysical studies of inhibitor binding and their effect on IDH1 reactions.

a compound 1 binding to IDH1^R132H affects NADP+ interactions using ligand-detected STD NMR. b Changes in NADPH concentration are measured to assess IDH1^R132H inhibition by compound 1. c All substrates and products from IDH1^R132H reduction and oxidation reactions can be monitored simultaneously using 1H NMR in “one pot” reactions. d Addition of compound 1 to the IDH1^R132H oxidation reaction has little effect on ICT-to-aKG conversion (wild-type reaction) but inhibits aKG-to-2HG reduction. e Multicomponent IDH1^wt/R132H reaction monitoring shows aKG pooling. f ¹⁹F NMR studies of compound 4 complexes with IDH1^wt (black), IDH1^R132H (red), IDH1^wt/132H (blue) enzymes and free in solution (green). g Differences in deuterium incorporation measured by 1H NMR suggest differences in processing aKG by IDH1^wt and IDH1^R132H enzymes.