Redox specificity of 2-hydroxyacid-coupled NAD(+)/NADH dehydrogenases: a study exploiting "reactive" arginine as a reporter of protein electrostatics.

ABSTRACT: With "reactive" arginine as a kinetic reporter, 2-hydroxyacid dehydrogenases are assessed in basis of their specialization as NAD(+)-reducing or NADH-oxidizing enzymes. Specifically, M4 and H4 lactate dehydrogenases (LDHs) and cytoplasmic and mitochondrial malate dehydrogenases (MDHs) are compared to assess if their coenzyme specificity may involve electrostatics of cationic or neutral nicotinamide structure as the basis. The enzymes from diverse eukaryote and prokaryote sources thus are assessed in "reactivity" of functionally-critical arginine as a function of salt concentration and pH. Electrostatic calculations were performed on "reactive" arginines and found good correspondence with experiment. The reductive and oxidative LDHs and MDHs are assessed in their count over ionizable residu

SUBMITTER: Gupta P 

PROVIDER: S-EPMC3877072 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature