Antimycin inhibition of the cytochrome bd complex from Azotobacter vinelandii indicates the presence of a branched electron transfer pathway for the oxidation of ubiquinol

FEBS Letters

Jünemann, Susanne¹  Wrigglesworth, John M.¹ 

[1] Metals in Biology and Medicine Centre, Division of Life Sciences, King's College London, Campden Hill Road, London, W8 7 AH, UK

关键词: Cytochrome bd;    Antimycin A;    Azotobacter vinelandii;    UHDBT;    undecylhydroxydioxobenzothiazole;    TMPD;    N;    N;    N′;    N′-tetramethyl-p-phenylenediamine;    DTT;    dithiothreitol;   

DOI  :  10.1016/0014-5793(94)00372-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Antimycin A and UHBDT inhibit the activity of the purified cytochrome bd complex from Azotobacter vinelandii. Inhibition of activity is non-competitive and antimycin A binding induces a shift to the red in the spectrum of a b-type haem. No inhibitory effects were seen with myxothiazol. Steady-state experiments indicate that the site of inhibition for antimycin A lies on the low-potential side of haem b ₅₅₈. In the presence of antimycin A at concentrations sufficient to inhibit respiration, some direct electron transfer from ubiquinol-1 to haem b ₅₉₅ and haem d still occurs. The results are consistent with a branched electron transfer pathway from ubiquinol to the oxygen reduction site.

【 授权许可】

Unknown