STRUCTURE/FUNCTION & BIOSYNTHESIS OF RESPIRATORY ENZYMES

结构/功能

• 批准号: 6180259
• 负责人: VICTOR L DAVIDSON
• 金额: $ 24.26万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6180259
• 关键词: X ray crystallography; active sites; amine oxidoreductase; azurin; biophysics; chemical binding; chemical kinetics; cofactor; cytochrome c; electron nuclear double resonance spectroscopy; electron spin resonance spectroscopy; electron transport; enzyme biosynthesis; enzyme complex; enzyme mechanism; enzyme structure; enzyme substrate; nuclear magnetic resonance spectroscopy; protein protein interaction; quinones; respiratory enzyme; semiquinone; site directed mutagenesis; tryptophan

DESCRIPTION: The objective of this project is to define mechanisms of catalysis and electron transfer (ET) by selected quinoprotein dehydrogenases and their physiologic protein redox partners. These proteins are being used to develop and test hypotheses concerning (I) the roles of protein-bound quinone cofactors in catalysis and ET, (ii) mechanisms of long range interprotein ET reactions, and (iii) factors which stabilize the specific interactions between soluble proteins that facilitate intermolecular ET. study of physiologic ET reactions has for the most part been limited to integral membrane proteins for which structural information is difficult to obtain. Quinoprotein dehydrogenases are soluble and have two relatively unique and interesting properties. They utilize enzyme-bound quinones as prosthetic groups, and for electron acceptors they use other proteins rather than O2 or pyridine nucleotides. We are characterizing catalytic reaction mechanisms of the quinoproteins, developing kinetic models for their ET reactions, and determining crystal structures of these proteins free and in complex with physiologic redox partners. This allows us to correlate structural information with the results of our studies. A major aim of this proposal is to use site-directed mutagenesis to test hypothesis which have been developed concerning mechanisms of catalysis, protein-protein interaction and long range ET. Elucidation of factors which influence specific protein-protein interactions between quinoproteins and their electron acceptors will provide insight into the process of protein-protein recognition which is common to a wide range of biologic phenomena. Long range ET is a process which is central to bioenergetic phenomena such as respiration and certain reactions of intermediary metabolism. Characterization of the mechanisms and pathways of long range interprotein ET will allow us to better understand these fundamental processes at the molecular level.

描述：该项目的目的是定义 选定的喹蛋白脱氢酶的催化和电子转移（ET） 以及他们的生理蛋白氧化还原伴侣。 这些蛋白质正在使用 开发和检验有关（i）结合蛋白质的作用的假设 奎因酮辅因子在催化和ET中，（ii）远距离机理 解释蛋白ET反应和（iii）稳定特定的因素 促进分子间ET的可溶性蛋白之间的相互作用。 生理学和反应的研究大部分仅限于 结构信息难以为结构信息的整体膜蛋白 获得。 醌蛋白脱氢酶是可溶的，具有两个相对的 独特而有趣的属性。 他们利用酶结合的喹酮作为 假体群，对于电子受体，他们使用其他蛋白质而不是 比O2或吡啶核苷酸。 我们正在表征催化反应 喹他蛋白的机制，为其ET开发动力学模型 反应，并确定这些蛋白质的晶体结构，并在 与生理氧化还原伙伴的复杂性。 这使我们能够关联 结构信息与我们的研究结果。 这是一个主要目的 建议是使用定位的诱变来检验已有的假设 已经开发了有关催化，蛋白质蛋白质的机制 相互作用和远距离ET。 阐明影响因素 特异性蛋白质蛋白质蛋白及其之间的蛋白质相互作用 电子受体将深入了解蛋白质 - 蛋白质的过程 识别广泛的生物学现象共有的识别。 长的 范围ET是一个对生物能现象核心的过程，例如 中介代谢的呼吸和某些反应。 远程解释蛋白的机制和途径的表征 ET将使我们能够更好地理解这些基本过程 分子水平。