Protein-Protein Orientation and Dynamics in Electron-Transfer Reactions

电子转移反应中的蛋白质-蛋白质取向和动力学

• 批准号: 9222741
• 负责人: Nenad Kostic
• 金额: $ 29.1万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9222741&HistoricalAwards=false
• 关键词: Protein; Orientation; Dynamics; Electron; Transfer

9222741 Kostic The objective of this research is to understand the mechanism of electron transfer in electrostatic (noncovalent) protein/protein complexes. The molecular basis for the optimal reaction rate and specificity will be studied with the fully-characterized metalloproteins cytochrome c (cyt) and plastocyanin (pc). Building upon this laboratory's recent successes, a detailed plan is proposed that combines molecular biology (mutation of pc), computational chemistry (analysis of electron-transfer paths), and kinetics (laser flash photolysis) in order to achieve the following: (1) determine reactive orientations of cyt/pc complexes; (2) pinpoint dominant transfer paths from the heme to the Cu site; (3) examine how variations in distant electronic couplings controls the rate of electron transfer; (4) determine the rate of structural rearrangement of cyt/pc complexes and establish kinetic requirements for "gating"; and (5) explore the importance for electron transfer of conformational fluctuations at the protein/protein interface. %%% This research is important because electron-transfer reactions of metalloproteins are essential to various biological processes. These reactions are involved in animal metabolism and plant photosynthesis. A deeper understanding of electron transfer, at the molecular level, is necessary for a better understanding of the origin and transformations of chemical energy in a living cell. ***

9222741这项研究的目的是了解静电(非共价)蛋白质/蛋白质复合体中电子转移的机制。最佳反应速度和特异性的分子基础将用完全表征的金属蛋白细胞色素c(Cyt)和胞质蓝蛋白(PC)来研究。在本实验室最新成功的基础上，提出了一个结合分子生物学(PC的突变)、计算化学(电子转移路径分析)和动力学(激光闪光光解)的详细计划，以实现以下目标：(1)确定CyT/PC复合体的反应取向；(2)准确地确定从血红素到铜位的主要转移路径；(3)研究远距离电子偶合的变化如何控制电子转移的速率；(4)确定Cyt/PC复合体的结构重排速率，并建立“门控”的动力学要求；以及(5)探讨蛋白质/蛋白质界面构象涨落对电子转移的重要性。这项研究很重要，因为金属蛋白的电子转移反应在各种生物过程中是必不可少的。这些反应涉及动物新陈代谢和植物光合作用。为了更好地理解活细胞中化学能的来源和转换，在分子水平上更深入地理解电子转移是必要的。***