Molecular identification of the enzyme responsible for the mitochondrial NADH-supported ammonium-dependent hydrogen peroxide production

Abstract

A homogeneous protein with a subunit apparent molecular mass of ∼50 kDa that catalyzes the previously described mitochondrial NADH-supported ammonium-stimulated hydrogen peroxide production (Grivennikova, V.G., Gecchini, G. and Vinogradov, A.D. (2008) FEBS Lett. 583, 1287-1291) was purified from the mitochondrial matrix of bovine heart. Chromatography of partially purified protein showed that the peaks of ammonium-stimulated NADH-dependent H 2O2 production and that of NADH:lipoamide oxidoreductase activity coincided. The catalytic properties and mass spectrometry of the trypsin-digested protein revealed peptides that allowed identification of the protein as the Bos taurus dihydrolipoyl dehydrogenase. © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.