Abstract 1726 Kinetic Analysis of Human Mitochondrial Malate Dehydrogenase Phosphomimetic Mutant T212D with α-Ketoglutarate and Oxaloacetate

Malate dehydrogenase (MDH) is a key enzyme in the citric acid cycle that takes malate and NAD+ and converts it to oxaloacetate (OAA) and NADH. Under hypoxic conditions, it can also use α-ketoglutarate (αKG) as a substrate and convert it to L-2-hydroxyglutarate (2HG). 2HG levels are known to be elevated in cancer cells, which are typically hypoxic environments. We are studying how the phosphorylation of specific residues affects the enzymatic activity of MDH with respect to both OAA and αKG. We are doing this by creating phosphomimetic mutants, where the negative charge associated with phosphorylation is imitated by changing the residue of interest to a residue with a permanent negative charge like aspartate.