Laser flash photolysis studies of the kinetics of reduction of ferredoxins and ferredoxin-NADP+ reductases from Anabaena PCC 7119 and spinach: electrostatic effects on intracomplex electron transfer.
Laser flash photolysis studies of the kinetics of reduction of ferredoxins and ferredoxin-NADP+ reductases from Anabaena PCC 7119 and spinach: electrostatic effects on intracomplex electron transfer.
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鱼腥藻 PCC 7119 和菠菜中铁氧还蛋白和铁氧还蛋白-NADP 还原酶还原动力学的激光闪光光解研究：静电对复合物内电子转移的影响。
DOI：
10.1016/0003-9861(91)90489-6
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发表时间：
1991
影响因子：
3.9
通讯作者：
Tollin,G
中科院分区：
文献类型：
--
作者：
Walker,MC;Pueyo,JJ;Navarro,JA;Gómez-Moreno,C;Tollin,G
通过比较离子强度对鱼腥藻和菠菜中还原型铁氧还蛋白（Fd）和氧化型铁氧还蛋白-NADP+还原酶（FNR）之间电子转移反应动力学的影响，研究了静电力对氧化还原蛋白质间瞬时复合物形成和电子转移的影响.与thesanabaenaproteins，直接减少由激光产生的黄素半醌的FNR组分被抑制复合物形成在低离子强度，而Fd还原没有。菠菜系统得到了相反的结果。这些观察清楚地表明蓝藻和高等植物复合体之间的结构差异。对于鱼腥藻蛋白形成的复合物，结果表明静电力不是复合物稳定性的主要贡献者。然而，速率常数为intracomplex电子转移有一个双相依赖于离子强度，这表明结构重排内的瞬态复杂的促进电子转移。与theAnabaenacomplex相反，静电力对于菠菜Fd：FNR复合物的稳定是重要的，并且离子强度的变化对复合物内电子转移的限制速率常数几乎没有影响。这表明，在这种情况下，初始碰撞复合物的几何形状对于反应是最佳的。这些结果提供了一个清晰的说明，静电相互作用可能发挥不同的作用，在控制两个氧化还原蛋白质之间的电子转移。
The influence of electrostatic forces on the formation of, and electron transfer within, transient complexes between redox proteins was examined by comparing ionic strength effects on the kinetics of the electron transfer reaction between reduced ferredoxins (Fd) and oxidized ferredoxin-NADP+reductases (FNR) fromAnabaenaand from spinach, using laser flash photolysis techniques. With theAnabaenaproteins, direct reduction by laser-generated flavin semiquinone of the FNR component was inhibited by complex formation at low ionic strength, whereas Fd reduction was not. The opposite results were obtained with the spinach system. These observations clearly indicate structural differences between the cyanobacterial and higher plant complexes. For the complex formed by theAnabaenaproteins, the results indicate that electrostatic forces are not a major contributor to complex stability. However, the rate constant for intracomplex electron transfer had a biphasic dependence on ionic strength, suggesting that structural rearrangements within the transient complex facilitate electron transfer. In contrast to theAnabaenacomplex, electrostatic forces are important for the stabilization of the spinach Fd:FNR complex, and changes in ionic strength had little effect on the limiting rate constant for intracomplex electron transfer. This suggests that in this case the geometry of the initial collisional complex is optimal for reaction. These results provide a clear illustration of the differing roles that electrostatic interactions may play in controlling electron transfer between two redox proteins.