Electron conduction between b cytochromes of the mitochondrial respiratory chain in the presence of antimycin plus myxothiazol.
The b haems of the bc1 complex of bovine heart mitochondria were poised with succinate and fumarate so that only the high-potential haem (b-562) was reduced, and then isolated from further redox exchange with the ubiquinone pool by adding antimycin and myxothiazol. A transmembrane electric potential difference was then developed, either by electron flow from [Ru(NH3)6]Cl2 to oxygen or by ATP hydrolysis. The small difference spectrum, caused by the electric field, indicated 32-55% oxidation of b-562 with concomitant reduction of b-566. No lag greater than 0.1 s was detectable between the initiation of respiration and the development of the difference spectrum, thus providing a direct demonstration of (fairly) rapid electron transfer between the b haems.
West
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Glynn Research Institute, Bodmin, U.K.
Mitchell
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Rich
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D000818:Animals; D000968:Antimycin A / Q000031:analogs & derivatives* / Q000494:pharmacology; D002417:Cattle; D003573:Cytochrome b Group / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004579:Electron Transport / Q000187:drug effects; D029968:Escherichia coli Proteins; D005650:Fumarates / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D008689:Methacrylates; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D010084:Oxidation-Reduction; D013053:Spectrophotometry; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid; D013844:Thiazoles / Q000494:pharmacology
D003573:Cytochrome b Group; D029968:Escherichia coli Proteins; D005650:Fumarates; D008689:Methacrylates; D013386:Succinates; D013844:Thiazoles; C032456:antimycin; C020730:cytochrome b566; D000968:Antimycin A; C030517:myxothiazol; C032005:fumaric acid; C017850:cytochrome b562, E coli; D019802:Succinic Acid