THEORETICAL STUDY OF BIOLOGICAL ELECTRON TRANSFER

描述：（改编自申请人的摘要）理解 电子如何长距离穿透蛋白质有机介质 对于许多生物过程的表征至关重要，例如 光合作用和呼吸作用。 一个广泛的长期目标， 拟议的研究是发展一个详细的量子力学 复杂分子中长距离电子转移反应的图像 涉及蛋白质和DNA的系统。 为了实现这一目标， 计算机模拟，与实验数据的比较，以及系统 光诱导电子转移动力学的理论分析 反应将进行各种新的复杂分子， 最近已经被实验研究的系统。 在这些 系统中，两个过渡金属配合物，供体和受体， 反应，被一个大的生物分子，如蛋白质， 或DNA，介导光诱导的电子转移反应。 具体而言，非弹性隧穿的作用，对称性效应的 供体和受体状态，以及结构和 将研究生物隧穿的动力学方面。 将被研究的系统包括修饰的细胞色素，如 Ru（bpy）2 im（his X）-cyt-c、天青蛋白、肌红蛋白和一些其他 金属蛋白，其中Ru络合物结合到基因工程 蛋白质表面的组氨酸;同样，可变长度的DNA 将从理论上研究含有束缚Ru络合物的螺旋。 配合物的π轨道体系的电子转移性质将 追究 DNA和蛋白质复合物将用于研究 距离，结构，碱基对序列 分子内电荷转移速率的依赖性。 拟议 研究将提供如何结构和 生物分子的动力学最多控制电荷转移 基本量子力学水平。

DESCRIPTION: (Adapted from the applicant's abstract) An understanding of how electrons tunnel long distances through organic media of proteins is crucial for the characterization of many biological processes, such as photosynthesis and respiration. A broad long-range goal of the proposed research is the development of a detailed quantum mechanical picture of long-distance electron transfer reactions in complex molecular systems that involved proteins and DNA. In order to achieve this goal, computer simulations, comparison with experimental data, and systematic theoretical analysis of the dynamics of photoinduced electron transfer reactions will be carried out for a variety of novel complex molecular systems that recently have been studied experimentally. In these systems, two transition metal complexes, donor and acceptor in the reaction, are separated by a large biological molecule, such as protein or DNA, that mediates a photoinduced electron transfer reaction. Specifically, the role of inelastic tunneling, symmetry effects of the donor and acceptor states, and interplay between structural and dynamical aspects of the biological tunneling will be investigated. Systems that will be studied include modified cytochromes, such as Ru(bpy)2im(his X)-cyt-c, azurin, myoglobin, and some other metalloproteins in which a Ru complex is bound to genetically engineered histidines on the surface of the protein; similarly, variable-length DNA helices containing a bound Ru-complex will be studied theoretically. Electron transfer properties of the pi-orbital system of the complex will be investigated. The DNA and protein complexes will be used to study the distance, as well as the structure, and base pair sequence dependence of intramolecular charge transfer rates. The proposed research will provide a quantitative understanding of how structure and dynamics of biological molecules controls charge transfer at the most fundamental quantum mechanical level.