Cytochrome oxidase‐catalyzed superoxide generation from hydrogen peroxide

FEBS Letters

Berka, V.³  Vygodina, T.V.¹  Konstantinov, A.A.¹  Ksenzenko, M.Yu.¹  Ruuge, E.K.² 

[1] A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119 899, USSR;Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Solovienova 47, CSFR;Faculty of Physics, Moscow State University, Moscow, 119 899, USSR

关键词: Cytochrome c oxidase;    Superoxide radical;    Spin trapping;    Oxygen intermediate;    Respiratory chain;    COX;    cytechrome c oxidase;    DMPO;    5;    5-dimethyl-1-pyrroline-N-oxide;    SOD;    superoxide dismutase;    DETAPAC;    diethylenetriamine pentaacetate;   

DOI  :  10.1016/0014-5793(92)80328-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Superoxide dismutase is shown to affect spectral changes observed upon cytochroma c oxidase reaction with H₂O₂, which indicates a possibility of O⁻ ₂ radicals being formed in the reaction. Using DMPO as a spin trap, generation of superoxide radicals from H₂O₂ in the presence of cytochrome oxidase is directly demonstrated. The process is inhibited by cyanide and is not observed with a licat-denatured enzyme pointing to a speciric reaction in the oxygen-reducing centre of cytochrome c oxidase. The data support a hypothesis on a catalase cycle catalysed by cylochrome c oxidase in the presence of excess H₂O₂ (Vygodina and Konstantinov (1988) Ann. NY Acad. Sci., 550, 124-138);

【 授权许可】

Unknown