The assignment of the 655 nm spectral band of cytochrome oxidase

FEBS Letters

Mitchell, Roy¹  Rich, Peter R.¹  Mitchell, Peter¹ 

[1] Glynn Research Institute, Bodmin, Cornwall PL30 4AU, UK

关键词: Cytochrome oxidase;    Binuclear centre;    655 nm band;    Midpoint potential;   

DOI  :  10.1016/0014-5793(91)80321-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The spectral characteristics of the ‘655 nm’ band of cytochrome oxidase were found to be affected by ligands of the binuclear centre, including formate and chloride, and by the resting/pulsed transition. The band titrated with near n=1 characteristics at a midpoint of about 400 mV, in contrast to haem a ₃, which exhibits strong redox interaction and a titration range at significantly lower potential. Thus, although the total reduced-oxidised difference spectrum of haem a ₃, shows a trough at about 655 nm, this characteristic is absent in the low potential region. The 655 nm feature may arise from a charge transfer band of ferric high-spin haem a ₃, which is modulated by the redox state of Cu_B, as suggested by Beinert et al. [(1976) Biochim. Biophys. Acta 423, 339–355].

【 授权许可】

Unknown