Transient kinetics of electron transfer reactions of flavodoxin: ionic strength dependence of semiquinone oxidation by cytochrome c, ferricyanide, and ferric ethylenediaminetetraacetic acid and computer modeling of reaction complexes.
Transient kinetics of electron transfer reactions of flavodoxin: ionic strength dependence of semiquinone oxidation by cytochrome c, ferricyanide, and ferric ethylenediaminetetraacetic acid and computer modeling of reaction complexes.
复制标题
黄素氧还蛋白电子转移反应的瞬态动力学：细胞色素c、铁氰化物和乙二胺四乙酸铁对半醌氧化的离子强度依赖性以及反应复合物的计算机建模。
DOI：
10.1021/bi00268a008
复制
发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Tollin,G
中科院分区：
文献类型：
--
作者：
Simondsen,RP;Weber,PC;Salemme,FR;Tollin,G
摘要：用停流分光光度法研究了巴氏梭菌黄酮半喹酮与多种氧化剂[马心细胞色素c、铁氰化铁和乙二胺四乙酸(EDTA)]之间的电子转移反应。细胞色素C反应是复杂的，因为存在两种细胞色素物种，它们的反应速度不同，其相对浓度与离子强度有关。这里只考虑这两种反应中较快的一种。在低离子强度时，细胞色素c与黄还蛋白形成络合物，在高浓度时，其拟一级反应速率常数趋于平缓。无论是铁氰化铁还是EDTA铁都没有观察到这一点。对于细胞色素c，络合物形成的速率和缔合常数随浓度的降低而增大。
Royce P. Simondsen, Patricia C. Weber, 1 FR Salemme, 1 and Gordon Tollin* abstract: Electron transfer reactions between Clostridum pasteurianum flavodoxin semiquinone and various oxidants [horse heart cytochrome c, ferricyanide, and ferric ethylene-diaminetetraacetic acid (EDTA)] have been studied as a function of ionic strength by using stopped-flow spectropho-tometry. The cytochrome c reaction is complicated by the existence of two cytochrome species which react at different rates and whose relative concentrations are ionic strength dependent. Only the faster of these two reactions is considered here. At low ionic strength, complex formation between cytochrome c and flavodoxin is indicated by a leveling off of the pseudo-first-order rate constantat high cytochrome c con-centration. This is not observed for either ferricyanide or ferric EDTA. For cytochrome c, the rate and association constants for complex formation were found to increase with decreasing