BIOLOGICAL ELECTRON TRANSFER

生物电子转移

• 批准号: 2391828
• 负责人: MICHAEL Anthony CUSANOVICH
• 金额: $ 26.06万
• 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 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2391828
• 关键词: Rhodospirillales; X ray crystallography; chemical kinetics; computer simulation; cytochrome c; electron transport; flavoproteins; guanidines; iron sulfur protein; nuclear magnetic resonance spectroscopy; oxidation reduction reaction; photosynthetic reaction centers; protein structure function; site directed mutagenesis; thermodynamics

The focus of this research is to understand the mechanisms of biological electron transfer and, in a broader sense, the relationship between structure and function in redox proteins and proteins in general. The specific aims are three-fold: first, utilizing site-directed mutagenesis coupled with structural, kinetic and thermodynamic studies to elucidate the factors mediating physiologically relevant electron transfer by the cytochromes c; second, to understand how the oxidation-reduction potential is controlled in the cytochromes c as well as the factors which control their stability and dynamic rearrangements; and, third, to investigate other families of redox protein which have unique or distinct properties relative to c-type cytochromes. Redox proteins are critical components in a variety of metabolic processes, including: respiration, photosynthesis, nitrogen fixation, denitrification, methanogenesis, steroid biosynthesis, DNA biosynthesis, chemical carcinogenesis and drug detoxification. In this context, the proposed studies are designed to elucidate the general principles that control biological electron transfer using c-type cytochromes (in particular cytochrome c2) in well defined and tractable model systems. It is anticipated that the proposed studies will elucidate both conceptually and technologically fundamental principles that will be applicable to most electron transfer systems and in particular physiologically relevant reactions which involve protein-protein interactions. In addition, we should obtain fundamental information on structure-function relations in proteins. These include a detailed understanding of biological recognition, that is, how physiologically relevant reactions between proteins occur in a complex metabolic mileu, and factors involved in the stabilization of native structures and the role of dynamic processes within proteins in modulating their structure and function. The approach is to couple studies of function (electron transfer kinetics in physiologically relevant reactions as well as model systems) with site-directed mutagenesis, structural studies (NMR and x-ray), stability measurement (redox potentials, spectral pK values, guanidine denaturation, hydrogen-deuterium exchange kinetics and ligand binding) and computer modeling of reactive species.

这项研究的重点是了解生物学的机制， 电子转移，以及在更广泛的意义上， 氧化还原蛋白质和一般蛋白质的结构和功能。 的 具体目标有三：首先，利用定点诱变 结合结构、动力学和热力学研究， 介导生理相关电子转移的因子 细胞色素c;第二，了解氧化还原电位如何 是由细胞色素c控制的， 它们的稳定性和动态重排;第三，研究 具有独特或不同性质的其他氧化还原蛋白家族 相对于C型细胞色素。 氧化还原蛋白质是 各种代谢过程，包括：呼吸作用，光合作用， 固氮，反硝化，甲烷生成，类固醇生物合成， DNA生物合成、化学致癌和药物解毒。 在这 在这种背景下，拟议的研究旨在阐明一般的 使用C型控制生物电子转移的原理 细胞色素（特别是细胞色素c2）在定义明确和易于处理 模型系统 预计拟议的研究将阐明 无论是概念上还是技术上， 适用于大多数电子转移系统， 涉及蛋白质-蛋白质的生理相关反应 交互. 此外，我们还应获得以下基本信息： 蛋白质的结构-功能关系。 其中包括详细的 生物识别的理解，也就是说， 蛋白质之间的相关反应发生在复杂的代谢环境中， 参与天然结构稳定的因素以及 蛋白质内调节其结构的动态过程， 功能 方法是将功能（电子转移）的研究 生理学相关反应的动力学以及模型系统） 通过定点诱变，结构研究（NMR和X射线）， 稳定性测量（氧化还原电位、光谱pK值、胍 变性、氢-氘交换动力学和配体结合）和 活性物质的计算机模拟。