Aerobic Reduction of Cytochrome b566 in Pigeon-Heart Mitochondria
Abstract
In anaerobic, uncoupled pigeon-heart mitochondria treated with oxidizable substrate, the cytochrome b 566 remains largely oxidized. In the presence of antimycin A, addition of oxygen induces a reduction of this cytochrome. The rate of cytochrome b 566 reduction is comparable to and dependent on the rate of cytochrome c 1 oxidation. Kinetic data suggest that either ubiquinone or another donor of similar potential provides electrons for the reduction of cytochrome b 566. It is postulated that the aerobic reduction of cytochrome b 566 is directly related to the energy conservation at site II.
