Effect of ethoxyformic anhydride on the Rieske iron—sulfur protein of bovine heart ubiquinol: Cytochrome c oxidoreductase

FEBS Letters

Ohnishi, T.¹  Hatefi, Y.²  Yagi, T.²  Meinhardt, S.W.³  von Jagow, G.⁴ 

[1] Department of Biochemistry and Biophysics, Johnson Research Foundation, University of Pennsylvania, Philadelphia, PA 19104, USA;Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA;Department of Biochemistry, North Dakota State University, Fargo, ND 58105, USA;Department of Therapeutic Biochemistry, Center of Biological Chemistry, Frankfurt, Germany

关键词: Ethoxyformic anhydride;    Rieske iron—sulfur cluster;    EPR spectra;    Bovine ubiquinol-cytochrome c oxidoreductase;    bc 1 complex;    Complex III;   

DOI  :  10.1016/0014-5793(94)01021-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Treatment of bovine heart ubiquinol-cytochrome c oxidoreductase (complex III, bc ₁ complex) with ethoxyformic anhydride (EFA) inhibits electron transfer between cytochromes b and c ₁ [Yagi et al., Biochemistry 21 (1982) 4777–4782]. This paper shows that EFA alters the EPR lineshape of the Rieske iron—sulfur cluster in complex III and in the isolated Rieske protein without a significant decrease of spin concentration. The effect of EFA on the Rieske iron—sulfur cluster is competitive with that of Q_o site inhibitors, such as stigmatellin, and is completely reversed by hydroxylamine. These results are consistent with the possible ethoxyformylation by EFA of histidine ligands of the Rieske iron—sulfur cluster at the non-iron binding imidazole nitrogens.

【 授权许可】

Unknown