Inhibition of the alternative oxidase stimulates H2O2 production in plant mitochondria.
The hypothesis that a non-coupled alternative oxidase of plant mitochondria operates as an antioxygen defence mechanism [Purvis, A.C. and Shewfelt, R.L., Physiol. Plant. 88 (1993) 712-718; Skulachev, V.P., Biochemistry (Moscow) 59 (1994) 1433-1434] has been confirmed in experiments on isolated soybean and pea cotyledon mitochondria. It is shown that inhibitors of the alternative oxidase, salicyl hydroxamate and propyl gallate strongly stimulate H2O2 production by these mitochondria oxidizing succinate. Effective concentrations of the inhibitors proved to be the same as those decreasing the cyanide-resistant respiration. The inhibitors proved to be ineffective in stimulating H2O2 formation in rat liver mitochondria lacking the alternative oxidase.
Popov
V N
VN
Biological Department, Voronezh State University, Russia.
Simonian
R A
RA
Skulachev
V P
VP
Starkov
A A
AA
D000818:Animals; D000975:Antioxidants; D019069:Cell Respiration / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology; D024101:Mitochondrial Proteins; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D018532:Pisum sativum / Q000201:enzymology; D010940:Plant Proteins; D011190:Potassium Cyanide / Q000494:pharmacology; D011435:Propyl Gallate / Q000494:pharmacology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D012457:Salicylamides / Q000494:pharmacology; D013025:Glycine max / Q000201:enzymology; D019802:Succinic Acid / Q000378:metabolism; D000099188:Alternative Oxidase
D000975:Antioxidants; D004791:Enzyme Inhibitors; D006861:Hydrogen Peroxide; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D011190:Potassium Cyanide; D011435:Propyl Gallate; D017382:Reactive Oxygen Species; D012457:Salicylamides; D019802:Succinic Acid; D000099188:Alternative Oxidase; C005703:salicylhydroxamic acid