U.S. -Russia Joint Cooperative Research: Charge Transfer and Translocation in Biological Membranes

9316565克莱默该项目的目的是获得更深入的了解生物膜中的电荷转移过程的物理机制，特别是在膜结合的细胞色素和极性氨基酸跨膜易位的电子转移。 光谱，电化学，动力学模型蛋白质和血红素复合物的物理化学实验和理论研究将结合生物化学，生物物理晶体学，光合电子传递蛋白（细胞色素）和细菌离子通道（colicin）的离子易位的结构功能的分子生物学分析。 通过这些研究，我们将进一步认识以下问题：生物电荷转移过程中蛋白质及其周围介质介电重组的特殊性;细胞色素中电子传递的机制，包括静电场对血红素氧化还原电位的影响、内球重组、介电环境重组（膜核心，脂质头）和通过α-螺旋的电子耦合;细胞色素f-质体蓝素系统中的对接和电子转移机制;描述膜内蛋白质取向的“顺式规则”的物理基础;大肠杆菌素和相关毒素样分子形成跨膜通道的机制。 该项目的目的是更好地了解电荷在与生物材料接壤和包含生物材料的膜中转移或防止转移的机制。 膜中电荷运动的过程与发生在这些膜中的细胞能量储存机制以及与细胞结构和膜本身组装相关的蛋白质跨膜转运机制密切相关。 ***

9316565 Cramer The objective of the project is to obtain deeper insight into physical mechanisms of the charge transfer processes in biological membranes, in particular electron transfer in membrane-bound cytochromes and polar amino acid translocation across membranes. Physico-chemical experimental and theoretical studies of spectra, electrochemistry, and kinetics of model proteins and heme complexes would be combined with biochemical, biophysical crystallographic, and molecular biological analysis of the structure-function of photosynthetic electron transport proteins (cytochromes) and ion translocation of a bacterial ion channel (colicin). The problems whose understanding will be advanced as a result of these studies are as follows: the specific features of the dielectric reorganization of proteins and their surroundings in biological charge transfer processes; the mechanism of electron transfer in cytochromes including effects of electrostatic fields on the heme redox potentials, inner-sphere reorganization, reorganization of dielectric environment (membrane core, lipid heads), and electronic coupling via alpha-helices; mechanism of docking and electron transfer in the cytochrome f-plastocyanin system; the physical basis of the "cis-positive rule," describing orientation of intramembrane proteins; mechanism of trans-membrane channel formation by colicin and related toxin-like molecules. %%% The object of the project is to obtain a better understanding of the mechanism by which electrical charge is transferred or prevented from being transferred in the membranes that border and contain biological materials. The processes of charge movement in membranes are closely related to the mechanisms of cellular energy storage that take place in these membranes, and of the translocation of proteins across membranes that is associated with in the assembly of cellular structures and of the membranes themselves. ***