Spectroscopic identification of the axial ligands of cytochrome b 560 in bovine heart succinate‐ubiquinone reductase

FEBS Letters

Johnson, Michael K.²  Yu, Chang-An¹  Crouse, Brian R.²  Yu, Linda¹ 

[1]Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA

[2]Department of Chemistry and the Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602, USA

关键词: Succinate-ubiquinone reductase;    Succinate dehydrogenase;    Quinone binding protein;    Cytochrome b 560;    Electron paramagnetic resonance;    Magnetic circular dichroism;    SQR;    succinate-quinone reductase;    QFR;    quinol-fumarate reductase;    QP;    quinone-binding protein;    SDH;    succinate dehydrogenase;    FRD;    fumarate reductase;    HALS;    highly anisotropic low spin;    MCD;    magnetic circular dichroism;   

DOI  :  10.1016/0014-5793(95)00522-B

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The axial ligands of low potential cytochrome b ₅₆₀ in the five subunit bovine heart succinate-ubiquinone reductase complex and in the isolated quinone binding proteins have been investigated using EPR and near-infrared magnetic circular dichroism spectroscopies. The results are consistent with bis-histidine ligation with near-perpendicular imidazole rings for cytochrome b ₅₆₀ in the four-subunit complex. The pronounced changes in EPR properties that accompany isolation of the cytochrome-b ₅₆₀ containing quinone binding proteins, are attributed to perturbation of the orientation of the imidazole rings of the heme bis-histidine ligands, rather than a change in axial ligation.

【 授权许可】

Unknown