PROTON AND ELECTRON TRANSFER AND ENERGY COUPLING

该项目的最终目标是阐明结构- 站点I和站点III能量耦合的函数关系。我们 有三个主要的长期目标，即(A)测试 假设I位的电子转移机制是 属于循环型的。这一假设使我们能够解释(A) 氧化还原组分和蛋白质亚基的极端复杂性 结构，(B)H+/2e的高(四到五)化学计量比-(C) 团簇N-1a的中势极低。 为实现这一目标，我们将做以下工作：(1)研究物理学-- H~+-载体的化学性质，(II)研究新的 不同于传统鱼藤酮型的缓蚀剂 化合物，(Iii)测量氧化还原的空间组织 膜中的成分采用连续波和脉冲 低温下的EPR技术，以及(Iv)研究更简单 细菌系统，如反硝化副球藻和Thermus 嗜热菌HB-8。 (B)将我们在研究场地I方面的经验应用于临床 有问题。某些疾病是由体内的基因缺陷引起的。 位点I中的铁硫蛋白。我们已经证明了这一点 通过EPR测量可以清楚地识别缺陷 病理标本。我们将继续这条研究路线。 (C)阐明场地III的结构功能关系 呼吸。自从我们开创了自旋测量的先河 Cyt.a3-NO与其他顺磁物种的相互作用 牛心脏细胞色素氧化酶，我们将通过 进行以下实验：(1)最终测量 牛心脏细胞色素氧化酶的簇间距离，(II) 脉冲EPR仔细直接测量t1和t2 Cyt.A和CUA氧化还原平衡的拆分，(III)酵母菌的使用 谁的细胞。C氧化酶蛋白和生色团结构 受到双重突变的困扰。充分利用学习的优势 微生物，我们将研究光谱和热力学 氧化还原单组分的特征及对 氧化还原中心之间的氧化还原和自旋-自旋相互作用。 这些研究可望为我们的 对一号位电子和质子转移过程的认识 和分子水平上的III。

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.