Intermonomer electron transfer in the bc1 complex dimer is controlled by the energized state and by impaired electron transfer between low and high potential hemes
Intermonomer electron transfer in the bc1 complex dimer is controlled by the energized state and by impaired electron transfer between low and high potential hemes
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DOI：
10.1016/j.febslet.2007.03.037
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发表时间：
2007-04-17
期刊：
影响因子：
3.5
通讯作者：
Wraight, Colin A.
中科院分区：
文献类型：
--
作者：
Shinkarev, Vladimir P.;Wraight, Colin A.
细胞色素 bc(1) 复合物（通常称为复合物 III）是呼吸和光合作用电子传递链的中心酶。 X射线结构显示be复合物是二聚体，并表明低电位（b（L））和高电位（b（H））血红素之间的距离与不同单体中低电位血红素之间的距离相似。这表明单体之间的电子转移应该发生在 b(L) 血红素水平。在这里，我们表明，尽管 b(L) -> b(L) 电子转移的速率常数很大，但与从 b(L) 到 b(H) 的正向速率相比，其速度较慢，并且单体间转移仅在第一个单体内平衡后发生。单体间电子转移的有效速率比直接单体间电子转移慢约2个数量级。 (c) 2007 年欧洲生化学会联合会。由 Elsevier B.V. 出版。保留所有权利。
The cytochrome bc(1) complex (commonly called Complex III) is the central enzyme of respiratory and photosynthetic electron transfer chains. X-ray structures have revealed the be, complex to be a dimer, and show that the distance between low potential (b(L)) and high potential (b(H)) hemes, is similar to the distance between low potential hemes in different monomers. This suggests that electron transfer between monomers should occur at the level of the b(L) hemes. Here, we show that although the rate constant for b(L) -> b(L) electron transfer is substantial, it is slow compared to the forward rate from b(L) to b(H), and the intermonomer transfer only occurs after equilibration within the first monomer. The effective rate of intermonomer transfer is about 2-orders of magnitude slower than the direct intermonomer electron transfer. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.