Single electron reduction of ‘slow’ and ‘fast’ cytochrome‐c oxidase

FEBS Letters

Brandt, Ulrich²  Rich, Peter R.¹  Moody, A.John¹ 

[1] Glynn Research Institute, Bodmin, Cornvall, PL30 4AU, UK;Department of Biochemistry Darthmouth Medical School, Hanover, New Hampshire 03756, USA

关键词: Cytochrome-c oxidase;    Cytochrome c;    Electron transfer;    Binuclear centre;    Photoreduction;    Bovine heart;   

DOI  :  10.1016/0014-5793(91)81161-Z

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Evidence is presented that single electron reduction is sufficient for rapid electron transfer (k>20 s⁻¹ at pH 8.0 in 0.43 M potassium EDTA) between haem a/Cu_A and the binuclear centre in ‘fast’ oxidase, whereas in ‘slow’ oxidase intramolecular electron transfer is slow even when both Cu_A and haem a are reduced (k⋍2 s⁻¹). However, while a single electron can equilibrate rapidly between Cu_A, haem a and Cu_B in ‘fast’ oxidase, it seems that equilibration with haem a₃ is relatively slow (k⋍2 s⁻¹). Electron transfer between cytochrome c and Cu_A/haem a is similar for both types of enzyme (k=2.4×10⁵ M⁻¹·s⁻¹).

【 授权许可】

Unknown