CHEMBL5731323

Inhibition of Human SHMT: For the SHMT1 and SHMT2 in vitro enzymatic assays, the rate of 5,10-methylene tetrahydrofolate formation catalyzed by SHMT1/2 was indirectly evaluated by coupling with excess MTHFD2, which converts NAD+ to NADH allowing for reaction monitoring by absorption at 340 nm. The reaction was started by addition of serine (1 mM final) to either human SHMT1 or human SHMT2 (2 mcg/mL), and human MTHFD2 (25 mcg/mL) in a buffer of 50 mM potassium phosphate (pH 7.4), 0.3 mM tetrahydrofolate, 7.5 mM dithiothreitol, 1.25 mM NAD+, and 4% DMSO. Inhibition of initial reaction velocity was determined by adding various inhibitors at different concentrations and monitored as described. IC50 may be calculated based on this assay. For the MTHFD2 in vitro assay, the rate of NADH formation is directly monitored at 340 nm. The reaction is started by addition of 0.125 uM (final) of 5,10 methylene tetrahydrofolate to MTHFD2 (2.5 mcg/mL), 50 mM potassium phosphate (pH 7.4), 7.5 mM dithiothreitol, 1.25 mM NAD+, and 4% DMSO.