Formation and decay of cytochrome c peroxidase compound ES during aerobic redution with dithionite

FEBS Letters

Anni, Helen¹  Orii, Yutaka¹ 

[1] Department of Public Health, Faculty of Medicine, Kyoto University, Kyoto 606, Japan

关键词: Cytochrome c peroxidase;    Stopped-flow;    Rapid scanning;    Sodium dithionite;    Compound ES;    Hydrogen peroxide;    CcP;    cytochrome c peroxidase;    Mes;    2-(N-morpholino) ethanesulfonic acid;   

DOI  :  10.1016/0014-5793(90)80303-Z

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Stopped-flow and rapid scanning studies have clearly demonstrated that mixing of an oxygen-saturated solution of yeast cytochrome c peroxidase with sodium dithionite yields compound ES, indicating generation of H₂O₂. The formation of compound ES was most pronounced when [Na₂S₂O₄/[O₂] ≈ 1, and it reverted to the ferric form while standing. Even in the presence of an excess of dithionite ([Na₂S₂O₄]/[O₂] = 3.4) compound ES was formed immediately, but was soon replaced by the ferric form, followed by its final reduction to the ferrous state. The apparent first order rate constant for the decay of compound ES to the ferric form increased linearly with the square root of the dithionite concentration, thus involvement of SO⁻ ₂ in that process being suggested.

【 授权许可】

Unknown