Multifrequency EPR evidence for a bimetallic center at the CuA site in cytochrome c oxidase

FEBS Letters

Buse, Gerhard³  Kroneck, Peter M.H.²  Kastrau, Dieter H.W.²  Antholine, William E.⁴  Zumft, Walter G.¹  Steffens, Guy C.M.³ 

[1] Lehrstuhl für Mikrobiologie, Universität Karlsruhe, D-7500 Karlsruhe, FRG;Fakultät für Biologie, Universität Konstanz, D-7750 Konstanz, FRG;Institüt für Biochemie, Rheinisch-Westfälische Technische Hochschule Aachen, Klinikum, D-5100 Aachen, FRG;National Biomedical ESR Center Medical College of Wisconsin, Milwaukee, WI 53226, USA

关键词: Cytochrome c oxidase;    CopperA;    Bimetallic center;    Copper-copper interaction;    Nitrous oxide reductase;    Electron paramagnetic resonance;    multifrequency;    COX;    cytochrome c oxidase;    EPR;    electron paramagnetic resonance;    EXAFS;    extended X-ray absorption fine structure;    ICP-AES;    inductively coupled plasma-atomic emission spectroscopy;    MCD;    magnetic circular dichroism;    N2OR;    nitrous oxide reductase;   

DOI  :  10.1016/0014-5793(90)81026-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Multifrequency electron paramagnetic resonance (EPR) spectra of the Cu(II) site in bovine heart cytochrome c oxidase (COX) and nitrous oxide reductase (N2OR) from Pseudomonas stutzeri confirm the existence of Cu-Cu interaction in both enzymes. C-band (4.5 GHz) proves to be a particularly good frequency complementing the spectra of COX and N2OR recorded at 2.4 and 3.5 GHz. Both the high and low field region of the EPR spectra show the presence of a well-resolved 7-line pattern consistent with the idea of a binuclear Cu center in COX and N2OR. Based on this assumption consistent g-values are calculated for g_z and g_x at four frequencies. No consistent g-values are obtained with the assumption of a 4-line pattern indicative for a mononuclear Cu site.

【 授权许可】

Unknown