MOLECULAR MECHANISMS OF BIOLOGICAL REDOX REACTIONS

使用了各种光谱物理和动力学方法。 刻画重要的电子转移机制(S) 生物系统。重点放在酶复合体上。 线粒体电子转移链和在 金属黄素蛋白、黄嘌呤氧化酶。主要长期目标 的结构和动态属性 线粒体复合体足够详细的假说 节能机制(S)可以严谨 已评估。 主要的技术，光学、自然和磁感应 圆二色谱与电子顺磁共振波谱 将在平衡和动力学实验中使用； 核磁共振和共振拉曼光谱 与磁化率一起也将被利用。 需要解决的主要问题包括：a)结构和 细胞色素氧化酶e组分的动力学性质 氧桥的性质以及氧桥的结构和反应性 与过氧化氢加成。B)该方案的结构基础 纯化的细胞色素氧化酶的快速到缓慢的转变。C) 络合物III中铁-硫团簇的结构和反应活性。 D)亚铁血红素配基的特性和性质 络合物III的细胞色素及其光谱性质 两种b细胞色素之间的相互作用。E)动能 耗Q络合物III的反应性及其相互关系 泡囊酶中的质子转运和电子传递。 F)黄嘌呤氧化酶作用机理的定量分析。

A variety of spectroscopic physical and kinetic methods are used to characterize the mechanism(s) of electron transfer in important biological systems. Emphasis is placed on the enzyme complexes of the mitochondrial electron transfer chain and on the metalloflavoprotein, xanthine oxidase. Principal long-term goals are to define the structural and dynamic attributes of the mitochondrial complexes in sufficient detail that hypotheses for the mechanism(s) of energy conservation can be rigorously evaluated. The principal techniques, optical, natural and magnetically-induced circular dichroism and electron paramagnetic resonance spectroscopy will be employed in both equilibrium and kinetic experiments; nuclear magnetic resonance and resonance Raman spectroscopies together with magnetic susceptibility will also be utilized. Major issues to be addressed include: a) The structural and kinetic properties of e components of cytochrome oxidase, the nature of the oxygen bridge and the structure and reactivity of the adduct with hydrogen peroxide. b) The structural basis for the fast to slow transition in purified cytochrome oxidase. c) The structure and reactivity of the iron-sulfur cluster in Complex III. d) The identity and properties of the ligands to the heme iron i the cytochromes of Complex III and the nature of the spectroscopic interaction between the two b cytochromes. e) The kinetic reactivity of Q-depleted Complex III and the relationship between proton translocation and electron transfer in vesicular enzyme. f) Quantitative analysis of the mechanism of xanthine oxidase.