Discrimination between duroquinol oxidase activity and the terminal oxidation step of the cyanide-resistant electron transport pathway of plant mitochondria.
Comparison of the cyanide-resistant duroquinol oxidase activity of sub-mitochondrial particles from Arum maculatum L. with their ability to carry out a cyanide-resistant oxidation of NADH and succinate shows that heat-inactivation of the duroquinol oxidase activity does not proportionally affect NADH and succinate oxidation. Moreover, 1 microM antimycin inhibits duroquinol oxidase activity by 50% while not decreasing the rates of NADH and succinate oxidation. Therefore, the cyanide-resistant electron transport does not appear to be mediated by a "duroquinol oxidase", and a convincing proof of the existence of a specific protein acting as a cyanide-resistant oxidase in plant mitochondria is still lacking.
D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D004351:Drug Resistance; D004579:Electron Transport / Q000187:drug effects; D006358:Hot Temperature; D008928:Mitochondria / Q000201:enzymology*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010088:Oxidoreductases / Q000378:metabolism*; D010944:Plants / Q000201:enzymology* / Q000648:ultrastructure; D013367:Submitochondrial Particles / Q000201:enzymology; D013386:Succinates / Q000378:metabolism
D003486:Cyanides; D013386:Succinates; D009243:NAD; C032456:antimycin; D000968:Antimycin A; D010088:Oxidoreductases; C020094:duroquinol oxidase