Ammonium-dependent hydrogen peroxide production by mitochondria.
NADH-supported generation of H2O2 by permeabilized rat heart mitochondria was partially prevented by the specific complex I-directed inhibitor, NADH-OH, and was significantly stimulated by ammonium. Ammonium did not affect H2O2 production by complex I in coupled submitochondrial particles. The soluble mitochondrial matrix protein fraction catalyzed NADH-dependent H2O2 production, which was greatly (approximately 10-fold) stimulated by ammonium. We conclude that complex I is not the major contributor to mitochondrial superoxide (hydrogen peroxide) generation and that there are specific ammonium-sensitive NADH:oxygen oxidoreductase(s) in the mitochondrial matrix which are responsible for mitochondrial H2O2 production.
Grivennikova
Vera G
VG
Department of Biochemistry, School of Biology, Moscow State University, Moscow 119992, Russian Federation.
Cecchini
Gary
G
Vinogradov
Andrei D
AD
D000818:Animals; D002384:Catalysis; D002417:Cattle; D042967:Electron Transport Complex I / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats
D000644:Quaternary Ammonium Compounds; D009243:NAD; D006861:Hydrogen Peroxide; D042967:Electron Transport Complex I