Effect of ubiquinone extraction on ubiquinol-1 oxidase activity in beef heart mitochondria.
Extraction of endogenous ubiquinone with different methods does not influence ubiquinol oxidase activity in lyophilized mitochondria in terms of KM, although a decrease of Vmax is sometimes observed. Experiments with submitochondrial particles from a UQ-deficient mutant of S. cerevisiae confirm the results with UQ-depleted mitochondria and support the idea that endogenous ubiquinone is not required for the oxidation of exogenous ubiquinols by complex III.
D000818:Animals; D002417:Cattle; D008929:Mitochondria, Heart / Q000201:enzymology*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D011808:Quinone Reductases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013367:Submitochondrial Particles / Q000201:enzymology; D014451:Ubiquinone / Q000032:analysis / Q000502:physiology*
D014451:Ubiquinone; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; C030914:ubiquinol-1 oxidase; C025204:Ubiquinone Q2