Coupling site I and the rotenone‐sensitive ubisemiquinone in tightly coupled submitochondrial particles

FEBS Letters

Vinogradov, A.D.¹  Burbaev, D.Sh.²  Kotlyar, A.B.¹  Sled, V.D.¹  Moroz, I.A.² 

[1] Department of Biochemistry, School of Biology, Moscow State University, Moscow 119899, USSR;Institute of Chemical Physics, USSR Academy of Sciences, Moscow 117977, USSR

关键词: NADH-ubiquinone reductase;    Ubisemiquinone;    Electron transfer;    Mitochrondria;    Q;    ubiquinone-10;    BSA;    bovine serum albumin;    Hepes;    N(2-hydroxyethyl) piperazine-N-(2-ethanesulfonic acid);    CCCP;    carbonyl -cyanide m-chlorophenyl hydrazone;   

DOI  :  10.1016/0014-5793(90)80753-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The rotenone-sensitive g = 2.00 low temperature EPR signal attributed to ubisemiquinone is observed in submitochondrial particles during coupled electron transfer from NADH to oxygen and from succinate to NAD⁺. The signal is seen only in the presence of oligomycin added to induce the respiratory control (7–9 with NADH and 3–4 with succinate) and it disappears in the presence of uncouplers (CCCP or gramicidin D). No reduction of the iron-sulfur center N-2 in the presence of 20 mM succinate and cyanide is observed, thus suggesting that N-2 is not in equilibrium with the ubiquinone pool. A hypothesis is proposed on 7Delta;sm_H+ generation coupled with electron transfer between iron-sulfur center N-2 and the ubiquinone pool.

【 授权许可】

Unknown