PROTON AND ELECTRON TRANSFER AND ENERGY COUPLING

质子和电子转移以及能量耦合

• 批准号: 3278574
• 负责人: Tomoko None Ohnishi
• 金额: $ 23.35万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-02-01 至 1993-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3278574
• 关键词: Escherichia coli; bioenergetics; biological signal transduction; cellular respiration; chemical structure function; cow; cryoscience; cytochrome oxidase; electron spin resonance spectroscopy; electron transport; enzyme structure; flavins; fluorescent dye /probe; gram negative bacteria; hydrogen transport; iron; membrane potentials; menadione; metalloproteins; mitochondrial membrane; mutant; myocardium; oxidation reduction reaction; oxidoreductase inhibitor; photosynthetic bacteria; potentiometry; semiquinone; sulfur compounds; thermodynamics; ubiquinone; yeasts

The ultimate goal of the project is to elucidate the structure- function relationship of the Site I and Site III energy coupling. We have three major long term objectives, namely, (A) To test the hypothesis that the mechanism of electron transfer in the Site I is of a cyclic type. This hypothesis enables us to explain (a) the extreme complexity of redox components and protein subunit structure, (b) a high (four to five) stoichiometry of H+/2e- (c) the extremely low midpotential of the cluster N-la. For this goal, we will do the following: (i) study the physico- chemical properties of the H+-carriers, (ii) investigate new inhibitors which are different from conventional rotenone-type compounds, (iii) measure the spatial organization of the redox components in the membrane using continuous wave and pulsed EPR techniques at cryogenic temperature, and (iv) study simpler bacterial systems, such as Paracoccus denitrificans and Thermus thermophilus HB-8. (B) To apply our experience in the study of Site I to clinical problems. Certain diseases are caused by a genetic defect in the iron sulfur proteins in the Site I. We have demonstrated that this defect can be clearly identified by EPR measurement on pathological specimens. We will continue this line of study. (C) To elucidate the structure function relationship of Site III respiration. Since we pioneered the measurement of spin-spin interaction between cyt.a3-NO and other paramagnetic species in bovine heart cytochrome oxidase, we will complete the study by conducting the following experiments: (i) definitive measurement of inter-cluster distance in bovine heart cytochrome oxidase, (ii) direct measurement of T1 and T2 by pulsed EPR with careful resolution of redox poise of cyt.a and CuA, (iii) use of yeast strain whose cyt. c oxidase protein and chromophore structure are perturbed by double mutation. Taking full advantage of studying microorganism, we will study spectral and thermodynamic characteristics of individual redox components and analysis of the redox and spin-spin interactions among redox centers. These studies are expected to open a new horizon in our understanding of the electron and proton transfer process in Site I and III on the molecular level.

该项目的最终目标是阐明结构 - 网站I和站点III能量耦合的功能关系。 我们 有三个主要的长期目标，即（a）测试 假设位点I中电子传递的机理是 循环类型。 这个假设使我们能够解释（a） 氧化还原成分和蛋白质亚基的极端复杂性 结构，（b）H+/2e-的高（四到五）化学计量法 群集N-LA的极低中电势。 对于此目标，我们将执行以下操作：（i）研究物理学 - H+载体的化学特性，（ii）调查新的 与常规藤酮型不同的抑制剂 化合物，（iii）测量氧化还原的空间组织 使用连续波和脉冲的膜中的成分 低温温度下的EPR技术，（iv）研究更简单 细菌系统，例如denitrificans和Thermus 嗜热HB-8。 （b）将我们在网站I研究的经验应用于临床 问题。 某些疾病是由遗传缺陷引起的 网站上的铁硫蛋白。我们已经证明了这一点 可以通过EPR测量清楚地确定缺陷 病理标本。 我们将继续进行这一研究。 （c）阐明位点III的结构函数关系 呼吸。 由于我们开创了自旋旋转的测量 Cyt.A3-NO与其他顺磁性物种之间的相互作用 牛心脏细胞色素氧化酶，我们将通过 进行以下实验：（i）确定测量 牛心细胞色素氧化酶的簇间距离，（ii） 脉冲EPR对T1和T2进行直接测量，并仔细测量 Cyt.A和CuA的氧化还原固定的分辨率，（iii）使用酵母菌菌株 谁的细胞。 C氧化酶蛋白和发色团结构是 双重突变扰动。 充分利用学习 微生物，我们将研究光谱和热力学 单个氧化还原成分的特征和分析 氧化还原中心之间的氧化还原和自旋旋转相互作用。 这些研究有望在我们的 了解网站中的电子和质子传输过程 和III在分子水平上。