SUBSTRATE DOCKING IN CYTOCHROME C OXIDASE

细胞色素 C 氧化酶中的底物对接

• 批准号: 6316674
• 负责人: SHELAGH M FERGUSON-MILLER
• 金额: $ 10.47万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6316674
• 关键词: Raman spectrometry; Rhodospirillales; X ray crystallography; active sites; chemical binding; chemical kinetics; chemical structure function; chimeric proteins; cytochrome c; cytochrome oxidase; electron spin resonance spectroscopy; electron transport; enzyme activity; enzyme structure; enzyme substrate; ionic bond; mathematical model; protein binding; protein protein interaction; site directed mutagenesis; structural biology; ultracentrifugation; water

Project IV- Substrate Docking in Cytochrome c Oxidase (Ferguson-Miller, Kuhn, Garavito, Roberts) Cytochrome c oxidase is an intrinsic membrane protein whose complex energy transducing function involves electron transfer, reduction of oxygen to water and translocation of protons across the membrane. This proposal is aimed at determining the nature of the protein-protein interaction between cytochrome c and cytochrome c oxidase, which determines the rate and efficiency of electron delivery in the oxidase. Models will be developed for the docking sties for cytochrome c on CcOX by a powerful computational algorithm that uses protein electrostatic fields and van der Waals surfaces in a systematic orientation search of the intermolecular energies of the two proteins. The predictions of this model will be tested by mutation of Rhodobacter sphaeroides CcOX, comparison of the kinetics and binding of cytochrome c with the mutant and wild-type enzymes, and by crystallizing native and mutant forms of Rhodobacter CcOX and CcOX/cytochrome c complexes, to determine their structure by X-ray analysis. Homology modeling of the Rhodobacter sequence into the bovine oxidase coordinates (available to us from our collaborator, S. Yoshikawa) will permit computational analysis of the docking with a model closer to that of the bacterial enzyme. Conversely, creation of a chimeric bacterial enzyme with a mammalian coxII gene substituted for the Rhodobacter gene, will allow assays of binding to be done in a system that better corresponds to the mammalian oxidase structure and better matches the mammalian cytochrome c. Surface water at the oxidase/cytochrome c interface will also be analyzed to predict retained water molecules that may influence the chemistry of the interaction. Defining the role of electrostatics and other forces in this protein-protein interaction will increase our understanding of the mechanism and mechanics of electron transfer in the respiratory chain.

项目IV-细胞色素C氧化酶（Ferguson-Miller， 库恩，加拉维托，罗伯茨） 细胞色素C氧化酶是一种内在的膜蛋白，其复杂能量 转导函数涉及电子转移，氧气还原至 质子的水和跨膜的易位。该提议是 旨在确定蛋白质 - 蛋白质相互作用的性质 细胞色素C和细胞色素C氧化酶，它决定了速率和 氧化酶中电子递送的效率。模型将开发 用于对接的cox上的细胞色素c，由一个强大的计算 使用蛋白质静电场和范德华的算法 在系统方向搜索分子间能量的表面 两种蛋白质。该模型的预测将通过 Rhodobacter sphaeroides Ccox的突变，动力学的比较和 细胞色素C与突变体和野生型酶的结合，并通过 结晶的杜鹃花CCOX的天然和突变形式和突变形式 CCOX/细胞色素C复合物，以确定其结构 分析。杜鹃花序列到牛的同源性建模 氧化酶坐标（我们的合作者S. Yoshikawa可以使用） 将允许对扩展坞进行计算分析，该模型更接近 细菌酶。相反，创建嵌合细菌 用哺乳动物coxii基因取代杜鹃花基因的酶， 将允许在更好的系统中进行绑定的测定 对应于哺乳动物氧化酶结构，更好地匹配 哺乳动物细胞色素c。氧化酶/细胞色素C的地表水 还将分析界面以预测保留的水分子 可能会影响相互作用的化学。定义角色 这种蛋白质蛋白质相互作用中的静电和其他力将 增加我们对电子机制和力学的理解 在呼吸链中转移。