MUTATIONAL ANALYSIS OF MITOCHONDRIAL ELECTRON TRANSFER

线粒体电子传递的突变分析

• 批准号: 2177085
• 负责人: NEIL N HOWELL
• 金额: $ 22.18万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-01-01 至 1996-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2177085
• 关键词: Micrococcus; chemical binding; chemical stability; cytochrome b; cytochrome oxidase; electron spin resonance spectroscopy; electron transport; enzyme complex; enzyme inhibitors; enzyme mechanism; gene mutation; genetic models; heme; hydrogen transport; mitochondria; molecular site; oxidation reduction reaction; personal computers; protein sequence; protein structure function; respiratory protein; semiquinone; site directed mutagenesis; tissue /cell culture; ubiquinone

The long-term goal of this research is to understand the role of mitochondrially-encoded proteins in structure and function of the respiratory chain. This is an area with relevance to public health as there is a growing awareness that a number of human disorders are associated with defects in the mitochondrial respiratory chain. The more immediate focus is upon the molecular enzymology of electron transfer and proton uptake/release in the bc1 complex. The proposed research involves a mutational analysis of the Qi or ubiquinone reductase center of the protonmotive cytochrome beta protein, a mitochondrial gene product. A unique set of mutations in the mouse cytochrome beta gene have been isolated and shown to affect inhibitor binding and catalytic function at the Qi center. These mutations will be analyzed further to determine the effect of the amino acid substitutions upon the quinone redox chemistry at this site including the formation of the stable Qi semiquinone anion. As a complementary approach, site-directed mutagenesis of the Paracoccus cytochrome beta gene will be undertaken. The initial studies will involve the mutation of evolutionarily conserved acidic and basic amino acid residues which may be involved in controlling Qi semiquinone anion stability and function, and particularly the interaction between this redox intermediate and the cytochrome betaH heme group.

这项研究的长期目标是了解 线粒体编码的蛋白质的结构和功能 呼吸链。 这是一个与公共卫生相关的领域 人们越来越意识到许多人类疾病是 与线粒体呼吸链中的缺陷有关。 更多 直接的重点是电子转移的分子酶学和 BC1复合物中的质子摄取/释放。 拟议的研究涉及 对Qi或泛氨基酮还原酶中心的突变分析 质子运动细胞色素β蛋白，一种线粒体基因产物。 一个 小鼠细胞色素β基因中的独特突变已经是 孤立并显示出影响抑制剂的结合和催化功能 气中心。 这些突变将进一步分析，以确定 氨基酸取代对喹酮氧化还原化学的影响 在此站点，包括稳定的Qi半喹酮阴离子的形成。 作为一种互补方法，副群的位置定向诱变 将进行细胞色素β基因。 最初的研究将 涉及进化保守的酸性和碱性氨基的突变 可能涉及的Qi半喹酮阴离子的酸残基 稳定性和功能，尤其是此之间的相互作用 氧化还原中级和细胞色素betah heme组。