The antioxidant functions of cytochrome c

FEBS Letters

Pereverzev, Mikhail O¹  Korshunov, Sergey S¹  Krasnikov, Boris F¹  Skulachev, Vladimir P¹ 

[1] Department of Bioenergetics, A.N. Belozersky Institute of Physico-Chemical Biology and International Lazer Centre, Moscow State University, Moscow 119899, Russia

关键词: Cytochrome c;    Mitochondrion;    Reactive oxygen species;    Superoxide oxidation;    Antioxidant;    DNP;    2;    4-p-dinitrophenol;    FCCP;    p-trifluoromethylcarbonylcyanide phenylhydrazone;    PTP;    permeability transition pore;    ROS;    reactive oxygen species;    SOD;    superoxide dismutase;    TPP+;    tetraphenyl phosphonium;   

DOI  :  10.1016/S0014-5793(99)01525-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Low (C_1/2=1.5×10⁻⁷ M) concentrations of horse cytochrome c strongly inhibit H₂O₂ production by rat heart mitochondria under conditions of reverse electron transfer from succinate to NAD⁺. The effect is abolished by binding of cytochrome c with liposomes and is not prevented by SOD. Yeast cytochrome c is much less effective than the horse protein whereas acetylated horse cytochrome c is without effect. H₂O₂ formation stimulated by antimycin A is resistant to added cytochrome c. In inside-out submitochondrial vesicles, H₂O₂ production is suppressed by all three cytochrome c samples tested, but at higher concentrations (C_1/2 is about 5×10⁻⁷ M). In vesicles, SOD abolishes the cytochrome c inhibition. We conclude that extramitochondrial cytochrome c is competent in down-regulation of the Complex I H₂O₂ production linked to the reverse electron transfer. Such an effect is absent in the inside-out submitochondrial vesicles where another antioxidant cytochrome c function can be observed, i.e. the oxidation of O₂ ⁻ to O₂. A possible role of cytochrome c in the antioxidant defence is discussed.

【 授权许可】

Unknown