BIOLOGICAL ELECTRON TRANSFER

生物电子转移

• 批准号: 2173687
• 负责人: MICHAEL Anthony CUSANOVICH
• 金额: $ 23.95万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-03-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2173687
• 关键词: Rhodospirillum; X ray crystallography; bioenergetics; conformation; cytochrome c; cytochrome oxidase; electron transport; ferredoxin; genetic manipulation; hemoprotein; iron sulfur protein; metalloproteins; molecular cloning; molecular dynamics; molecular site; nuclear magnetic resonance spectroscopy; nucleic acid sequence; oxidation reduction reaction; peroxidases; photosynthesis; photosynthetic reaction centers; point mutation; protein structure function; site directed mutagenesis; yeasts

In the context of our overall objective of understanding the mechanisms of biological electron transfer, both structural and kinetic studies on c-type cytochromes and other redox proteins will be carried out. We have successfully developed the appropriate genetic system for the site-directed mutagenesis of Rhodobacter capsulatus cytochrome c2 and have characterized a number of mutants. Studies to this point have focused on the effect of mutations on electron transfer kinetics, redox potential, protein stability, protein dynamics and protein structure. In addition, substantial progress has been made on characterization of the structural and redox of properties of the high potential iron sulfur proteins and the cytochromes c'. Based on our findings to date, we are proposing a comprehensive and integrated plan to investigate the mechanism of electron transfer primarily utilizing mutants of cytochrome c2 and by studying their interaction with both wild-type and mutant photosynthetic reaction centers, cytochrome c peroxidase and cytochrome c1. Although the principal focus will be on cytochrome c2, we will carry out parallel but less extensive efforts with other families of redox proteins such as HIPIP, cytochrome c', plant ferredoxin, and multi-heme cytochromes. We are combining the use of site-directed mutagenesis with a range of approaches in order to define in molecular terms electron transfer between cytochrome c2 and electron donors and acceptors. Thus, studies on the kinetics of electron transfer will be combined with structural studies (NMR and x-ray crystallography), studies on protein stability, redox potentials and protein dynamics (NMR). It is anticipated that the proposed studies will permit us to address the role of electrostatics, sterics, distance between redox centers, relative orientation of interacting redox centers, intervening media through which electrons are transferred, and protein dynamics in biological electron transfer. The proposed studies will also address issues related to the control of biological redox potentials, the importance of specific amino acids to structural domains, to protein stability, and the factors controlling biological specificity and recognition that mediate protein-protein interactions.

在我们理解机制的整体目标的背景下 生物电子转移，c型的结构和动力学研究 将进行细胞色素和其他氧化还原蛋白。 我们有 成功地开发了适当的遗传系统为该地点定向 Rhodobacter capsulatus细胞色素C2的诱变，并具有表征 许多突变体。 到目前为止，研究的重点是 电子转移动力学，氧化还原电位，蛋白质的突变 稳定性，蛋白质动力学和蛋白质结构。 此外， 在结构的表征上取得了重大进展 和高电势铁硫蛋白的性质氧化还原和 细胞色素C'。 根据迄今为止我们的发现，我们提出了一个 全面和集成的计划来研究电子机制 转移主要利用细胞色素C2的突变体并研究其 与野生型和突变光合反应中心的相互作用， 细胞色素C过氧化物酶和细胞色素C1。 虽然主要重点 将在细胞色素C2上，我们将进行平行但不太广泛 与其他氧化还原蛋白家族的努力，例如Hipip，Cytochrome C'， 植物铁氧还蛋白和多血红素细胞色素。 我们将使用站点定向诱变的使用与一系列 为了用分子项定义电子传递的方法 细胞色素C2和电子供体和受体。 因此，研究 电子传递的动力学将与结构研究（NMR）合并 和X射线晶体学），蛋白质稳定性，氧化还原电位的研究 和蛋白质动力学（NMR）。 预计拟议的研究 将允许我们解决静电，英尺，距离的作用 在氧化还原中心之间，相互作用的氧化还原中心的相对取向， 介入电子传递的介质和蛋白质 生物电子转移的动力学。 拟议的研究也将 解决与控制生物氧化还原电位有关的问题， 特异性氨基酸对结构结构域的重要性，对蛋白质 稳定性以及控制生物学特异性和 识别介导蛋白质蛋白质相互作用的认识。