COMPUTER SIMULATION OF ELECTRON TRANSFER REACTIONS

电子转移（ET）反应在化学反应中起着核心作用。 和生物过程。 早期的实验和理论 研究已经确定了ET反应的关键因素， 一个定性的理解，使用连续模型， 溶剂后 然而，最近的实验提供了详细的 信息的水平，其中微观性质的实际 供体和受体的环境可能非常重要。 的 这项建议的基本目标是促进一个更 溶液和蛋白质中ET反应的微观描述 使用真实的分子模拟。 建议模拟ET 反应在几个关键的实验系统，重点放在 理论和实验之间的详细相关性 结果 我们建议的模拟研究将包括 （一）微观关联研究 能量和相应溶剂的活化之间 ET在溶液中的重组能和自由能， 在蛋白质中。 将作出重大努力， 化学修饰的蛋白质（例如Ru-细胞色素c）。 （二） ET反应动力学效应的微观模拟， 将速率常数与电介质 给定微环境的弛豫时间。 （三） 分子内Franck-Condon活化的计算 高放热反应中的屏障。 (iv)一项重大努力将 致力于详细的能量学和动力学的研究 细菌光合作用中的ET过程。 这个项目将尝试 利用X射线结构或反应中心来评估 相关电荷转移态的能量，并探讨 蛋白质偶极波动的影响。 (v)氧化还原 电子转移蛋白质的潜力将通过游离 能量摄动法 这项研究将包括计算 基因修饰对氧化还原电位的影响。

Electron Transfer (ET) reactions play a central role in chemical and biological processes. Early experimental and theoretical studies have identified the key factors in ET reactions and reach a qualitative understanding using a continuum model for the solvent. However, recent experiments are providing detailed information on the level where the microscopic nature of the actual environment of the donor and acceptor might be very important. The basic objective of this proposal is to contribute toward a more microscopic description of ET reactions in solution and proteins using actual molecular simulation. It is proposed to simulate ET reactions in several key experimental systems, focusing on the detailed correlation between the theoretical and experimental results. Our proposed simulation studies will include the following projects: (i) Studies of the microscopic correlation between activation from energies and the corresponding solvent reorganization energies and free energies for ET in solution and in proteins. Significant effort will be dedicated to studies of chemically modified proteins (e.g. Ru-cytochrome c). (ii) Microscopic simulation of dynamical effects in ET reactions, with the goal of correlating rate constants with the dielectric relaxation times of the given microenvironments. (iii) Calculations of the intramolecular Franck-Condon activation barriers in highly exothermic reactions. (iv) A major effort will be dedicated to studies of the detailed energetics and dynamics of ET processes in bacterial photosynthesis. This project will try to use the X-ray structure or the reaction center to evaluate the energies of relevant charge transfer states and to explore the effects of the fluctuations of the protein dipoles. (v) The redox potential of electron transfer proteins will be evaluated by free energy perturbation methods. This study will include calculations of the effects of genetic modifications on redox potentials.