ELECTRON TRANSFER PROCESSES IN IRON AND COPPER PROTEINS

铁和铜蛋白质中的电子转移过程

• 批准号: 3226251
• 负责人: HARRY B GRAY
• 金额: $ 17.35万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-05-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3226251
• 关键词: Fungi; chemical structure function; copper; cow; cytochrome b; electrochemistry; electron transport; enzyme structure; flash photolysis; hemoprotein; histidine; laboratory rat; metalloenzyme; nuclear magnetic resonance spectroscopy; oxidation reduction reaction; photochemistry; ruthenium; spectrometry; sulfur compounds

Electron-transfer (ET) reactions play a key role in many biological processes. In these systems the donor and acceptor sites can be separated by distances of 10-25 angstrom unit. Our aim is to probe the factors that control the rates of long-range ET: site- to-site distance, driving force, nature of the intervening protein medium and of the redox centers, and reorganization energy. We intend to study and to compare intramolecular long-range ET reactions in ruthenium (II/III) derivatives of structurally well- characterized iron and copper proteins: bovine cytochrome b5, Alcaligenes denitrificans azurin, and high-potential iron-sulfur proteins from Chromatium vinosum, Thiocapsa roseopersicina, and Chromatium gracile. We also intend to study mutants of rat cytochrome b5 with modifications designed to address medium and distance effects systematically. During the next three years, we propose: (1) to prepare highly purified samples of the above wild-type and mutant proteins labeled at selected surface histidine residues with ruthenium (II/III) reagents; (2) to characterize these modified proteins by spectroscopic and electrochemical measurements; (3) to determine by flash photolysis experiments the rates of ET between the protein redox center (iron-heme or other metal phorphyrin, blue copper, or iron-sulfur cluster) and the surface- bound ruthenium; and (4) to analyze the electronic (distance, medium) and energetic (driving force, reorganization energy, temperature) components of the long-range ET rates in these prototypal heme, blue cooper, and iron sulfur proteins. The proposed experiments will allow us to develop a better understanding of a fundamental process essential to all living organisms.

电子转移（ET）反应在许多生物反应中发挥着关键作用 流程。 在这些系统中，供体和受体位点可以是 间隔 10-25 埃单位的距离。 我们的目标是 探究控制远程 ET 速率的因素：位点- 位点距离、驱动力、干预蛋白质的性质 介质和氧化还原中心，以及重组能。 我们 打算研究和比较分子内长程 ET 结构良好的钌 (II/III) 衍生物中的反应 特征铁和铜蛋白：牛细胞色素 b5， 反硝化产碱菌天青蛋白和高电位铁​​硫 来自 Chromatium v​​inosum、Thiocapsa Roseopersicina 的蛋白质，以及 纤细铬。 我们还打算研究大鼠的突变体 细胞色素 b5 经过修饰，旨在解决介质问题 和距离效应系统地。 未来三年，我们建议：（一）做好充分准备 上述野生型和突变蛋白的纯化样品 用钌标记选定的表面组氨酸残基 (II/III)试剂； (2) 通过以下方式表征这些修饰的蛋白质 光谱和电化学测量； (3) 至 通过闪光光解实验确定 ET 速率 蛋白质氧化还原中心（铁血红素或其他金属 卟啉、蓝铜或铁硫簇）和表面- 结合钌； (4) 分析电子（距离、 中等）和精力充沛（驱动力、重组能量、 温度）这些中的远程蒸散率的组成部分 原型血红素、蓝铜蛋白和铁硫蛋白。 所提出的实验将使我们能够开发出更好的 了解对所有生命都至关重要的基本过程 有机体。