Oxidation-reduction potentials of cytochromes in Ascaris muscle mitochondria: high-redox-potential cytochrome b558 in complex II (succinate-ubiquinone reductase).

摘要: Oxidation-reduction midpoint potentials (Ems) were determined at pH 7.0 for cytochromes in the anaerobic respiratory chain of Ascaris mitochondria by redox titration techniques. Cytochrome b558, which is associated with complex II that functions as fumarate reductase terminal step chain, was shown to have an Em -34 mV isolated and -54 mitochondria. These values are much higher than value cytochrome b558. In contrast, Ems C + C1 b559.5 situ be 235 78 mV, respectively, comparable those their mammalian counterparts.