title: Effect of electron transfer inhibitors on superoxide generation in the cytochrome bc1 site of the mitochondrial respiratory chain.
abstract: Antimycin, 2-nonyl-4-hydroxyquinoline N-oxide and funiculosin induce O.2(-) generation by submitochondrial particles oxidizing succinate, whereas KCN, mucidin, myxothiazol or 2,3-dimercaptopropanol inhibit O.2(-) generation. Thenoyltrifluoroacetone does not induce superoxide production by itself but slightly stimulates the reaction initiated by antimycin. The results indicate that auto-oxidation of unstable ubisemiquinone formed in centre o of the Q-cycle generates most of the O.2(-) radicals in the cytochrome bc1-site of the mitochondrial respiratory chain.
mesh_terms: D000475:Alkenes / Q000494:pharmacology; D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology; D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D002417:Cattle; D004112:Dimercaprol / Q000494:pharmacology; D014450:Electron Transport Complex III; D005231:Fatty Acids, Unsaturated; D006912:Hydroxyquinolines / Q000494:pharmacology; D008689:Methacrylates; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D011808:Quinone Reductases / Q000378:metabolism*; D000073739:Strobilurins; D013481:Superoxides / Q000378:metabolism*; D013804:Thenoyltrifluoroacetone / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology
chemical_list: D000475:Alkenes; D000880:Anthraquinones; D005231:Fatty Acids, Unsaturated; D006912:Hydroxyquinolines; D008689:Methacrylates; D009097:Multienzyme Complexes; D000073739:Strobilurins; D013844:Thiazoles; D004112:Dimercaprol; D013481:Superoxides; C032456:antimycin; C008556:mucidin; C010494:nonyl-4-hydroxyquinoline-N-oxide; D013804:Thenoyltrifluoroacetone; C015286:funiculosin (anthraquinone); D000968:Antimycin A; C030517:myxothiazol; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; D014450:Electron Transport Complex III; D010100:Oxygen