BIOLOGICAL ELECTRON TRANSFER

目的是了解生物电子的机制， 在分子水平上的转移。 此外，根据拟议的 研究了生物特异性的实质性理解， 介导蛋白质-蛋白质和蛋白质-膜相互作用， 蛋白质的结构-功能关系。 电子 能量传递和耦合能量守恒是生命的基础， 因此，如果我们要了解这些现象， 完全理解活细胞。 众所周知，驾驶 力、静电、距离/空间、方向、介入介质和 蛋白质动力学都在控制电子的动力学中起作用， 分子之间的转移。 为了充分量化每个人的作用， 在这些因素中，我们建议开发五种特定的氧化还原蛋白质， 它们具有大体相似但不同的电子转移性质。 之所以选择这些系统，是因为它们各自具有不同的特性 根据控制生物学的因素， 电子转移 主要的方法是利用瞬态动力学 作为功能测定，使用可用的 结构信息和计算机图形，并使用的技术， 分子生物学（定点诱变），以充分利用这些 系统. 我们的具体目标包括：a）表征 I类C型细胞色素（Rps.荚膜细胞色素C2）， 铁-硫蛋白（白色坎皮翁铁氧还蛋白）和铜蛋白（白色 坎皮翁质体蓝素）与生理和 非生理反应物，以提供有关介导 B）对一组分子的结构分析， 高潜力的铁硫蛋白，以获得信息的控制， 氧化还原电位、蛋白质折叠和蛋白质生成，c） Rps细胞色素B/c1的表征。capsulata，一个例子， 一种复杂的（多发色团）膜蛋白， 复合物内电子转移和与细胞色素c2的相互作用， c）通过对不同蛋白质研究的比较，得出一个一般的 了解生物电子转移和利用 其他不太好的系统。

The objective is to understand the mechanism of biological electron transfer in molecular terms. Moreover, by the nature of the proposed studies a substantial understanding of biological specificity, the factors mediating protein-protein and protein-membrane interactions and structure-function relations in proteins will be obtained. Electron transfer and coupled energy conservation are fundamental to the life process thus an understanding of these phenomena is required if we are to fully understand the living cell. It is well established that driving force, electrostatics, distance/sterics, orientation, intervening media and protein dynamics all play a role in controlling the kinetics of electron transfer between molecules. In order to fully quantitate the role of each of these factors, we are proposing to exploit five specific redox proteins which have generally similar but distinct electron transfer properties. These systems were chosen as they each have different characteristics amenable to analysis in terms of the factors controlling biological electron transfer. The principal approaches are to use transient kinetics as an assay of function, interpretation of kinetics using available structural information and computer graphics, and using the techniques of molecular biology (site directed mutagenesis) to fully exploit these systems. Our specific aims include the following: a) characterization of examples of Class I c-type cytochromes (Rps. capsulata cytochrome c2), iron-sulfur proteins (white campion ferredoxin) and copper proteins (white campion plastocyanin) in terms of their interaction with physiological and non-physiological reactants to provide information on the factors mediating electron transfers in these systems, b) structural analysis of a group of high potential iron-sulfur proteins to obtain information on the control of oxidation-reduction potentials, protein folding, and phylogeny, c) characterization of cytochrome b/c1, from Rps. capsulata, an example of a complex (multichromophoric) membrane protein which will provide information on intracomplex electron transfer and interaction with cytochrome c2, and c) through comparison of the different protein studies derive a general understanding of biological electron transfer and the means to exploit other less well characterized systems.