The site of the redox‐linked proton pump in eukaryotic cytochrome c oxidases

FEBS Letters

Bonaventura, Celia¹  Peterson, Jim²  Bonaventura, Joseph¹  Godette, Gerald¹  Holm, David E.² 

[1] Marine Biomedical Center, Duke University Marine Laboratory, Beaufort, NC 28516, USA;Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487-0336, USA

关键词: Cytochrome oxidase;    EPR;    MCD;    Proton pump;    Shark;    CHES;    3-(cyclohexylamino)-1-propanesulfonic acid;    EDTA;    ethylenediaminetetraacetic acid;    EPR;    electron paramagnetic resonance;    HEPES;    N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid);    MES;    2-(N-morpholino)ethanesulfonic acid;    MCD;    magnetic circular dichroism;   

DOI  :  10.1016/0014-5793(95)00791-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The electronic spectra of fully oxidized derivatives of some cytochrome c oxidase preparations are distinctly pH dependent. In general, the observed spectral shifts are greater in the case of pulsed derivatives compared to resting preparations and also, greater for preparations of the enzyme from shark skeletal muscle compared to beef heart. The low temperature near-infrared magnetic circular dichroism spectrum of the fully oxidized shark enzyme is not pH dependent in the experimental range, indicating the sensitivity of the visible region electronic spectrum to variation in pH to be due principally to changes at the heme a ₃-Cu_B chromophore. The results are discussed in relation to proposed mechanisms of proton translocation in cytochrome c oxidase.

【 授权许可】

Unknown