Kinetics of electron transfer between soluble cytochrome c-554 and purified reaction center complex from the green sulfur bacterium Chlorobium tepidum
Kinetics of electron transfer between soluble cytochrome c-554 and purified reaction center complex from the green sulfur bacterium Chlorobium tepidum
复制标题
可溶性细胞色素 c-554 与来自绿硫细菌温热绿菌的纯化反应中心复合物之间的电子转移动力学
DOI：
10.1023/a:1014959715666
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发表时间：
2004
影响因子：
3.7
通讯作者：
P. Sétif
中科院分区：
文献类型：
--
作者：
M. Itoh;D. Seo;H. Sakurai;P. Sétif
可溶性细胞色素c-554(Mr∼10 kDa)是从绿色硫磺细菌Chlorobium tepium.在pH为7.0时，氧化还原滴定的中点氧化还原电位为+148 mV。在室温下，用闪光吸收光谱研究了从同一生物体中提纯的反应中心络合物氧化细胞色素c-554的动力学，结果表明，细胞色素c-554的反应伙伴是结合在反应中心的细胞色素c-551，而不是主要供体P840。测得细胞色素c-554向细胞色素c-551供电子的二级速率常数为1.7×107M−1 S−1，反应速率受反应介质离子强度的影响不大。
Soluble cytochrome c-554 (Mr ∼ 10 kDa) is purified from the green sulfur bacterium Chlorobium tepidum. Its midpoint redox potential is determined to be +148 mV from redox titration at pH 7.0. The kinetics of cytochrome c-554 oxidation by a purified reaction center complex from the same organism were studied by flash absorption spectroscopy at room temperature, and the results indicate that the reaction partner of cytochrome c-554 is cytochrome c-551 bound to the reaction center rather than the primary donor P840. The second-order rate constant for the electron donation from cytochrome c-554 to cytochrome c-551 was estimated to be 1.7×107 M−1 s−1. The reaction rate was not significantly influenced by the ionic strength of the reaction medium.