Lin Jianping, Balabin Ilya A, Beratan David N
Departments of Chemistry and Biochemistry, Duke University, Durham, NC 27708, USA.
Science. 2005 Nov 25;310(5752):1311-3. doi: 10.1126/science.1118316.
Structured water molecules near redox cofactors were found recently to accelerate electron-transfer (ET) kinetics in several systems. Theoretical study of interprotein electron transfer across an aqueous interface reveals three distinctive electronic coupling mechanisms that we describe here: (i) a protein-mediated regime when the two proteins are in van der Waals contact; (ii) a structured water-mediated regime featuring anomalously weak distance decay at relatively close protein-protein contact distances; and (iii) a bulk water-mediated regime at large distances. Our analysis explains a range of otherwise puzzling biological ET kinetic data and provides a framework for including explicit water-mediated tunneling effects on ET kinetics.
最近发现，氧化还原辅因子附近的结构化水分子在几个系统中加速了电子转移（ET）动力学。跨水界面的蛋白质间电子转移的理论研究揭示了三种独特的电子耦合机制，我们在此进行描述：（i）当两种蛋白质处于范德华接触时的蛋白质介导机制；（ii）在相对较近的蛋白质-蛋白质接触距离处具有异常弱的距离衰减特征的结构化水介导机制；以及（iii）在远距离处的大量水介导机制。我们的分析解释了一系列原本令人困惑的生物ET动力学数据，并提供了一个框架，用于纳入对ET动力学的明确水介导隧穿效应。
