The cupric site in nitrous oxide reductase contains a mixed‐valence [Cu(II),Cu(I)] binuclear center: A multifrequency electron paramagnetic resonance investigation

FEBS Letters

Antholine, William A.¹  Riester, Joachim²  Kroneck, Peter M.H.²  Zumft, Walter G.³ 

[1] National Biomedical ESR Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA;Fakultät für Biologie, Universität Konstanz, Postfach 5560, D-7750 Konstanz, FRG;Lehrstuhl für Mikrobiologie, Universität Karlsruhe, Kaiserstr. 12, D-7500 Karlsruhe, FRG

关键词: Nitrous oxide reductase;    Cytochrome c-oxidase;    Mixed-valence Cu center;    EPR;    multifrequency;    EPR;    electron paramagnetic resonance;    N2OR;    nitrous oxide reductase;   

DOI  :  10.1016/0014-5793(88)80987-6

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 nitrous oxide reductase (N₂OR) from Pseudomonas stutzeri confirm the assignment of the low field g value at 2.18 consistent with the seven line pattern observed at 9.31 GHz, 10 K. S-band spectra at 20 K are better resolved than the X-band spectra recorded at 10 K. The features observed at 2.4, 3.4, 9.31 and 35 GHz are explained by a mixed-valence [Cu(1.5)..Cu(1.5)] S= 1/2 species with the unpaired electron delocalized between two equivalent Cu nuclei. The resemblance of the N₂OR S-band spectra to the spectra for the EPR-detectable Cu of cytochrome c oxidase suggests that the S-band spectrum for cytochrome c oxidase measured below 30 K may also contain hyperfine splittings from two approximately equivalent Cu nuclei.

【 授权许可】

Unknown