SPECTROSCOPY AND FUNCTION OF REDOX METALLOPROTEINS

这个项目的中心目标是阐明基本的 参与氧化还原金属蛋白功能的因子。我们想 了解这些蛋白质如何促进电子转移和小 分子活化，它们如何施加动力学或热力学控制，以及 他们如何保存或利用能源的过程中，他们 催化剂我们的方法强调振动光谱， 对结构敏感。特别是，我们强调时间分辨 振动探针提出了以下具体目标。 血红素-铜氧化酶。(i)我们想了解 不同物种的氧化酶。(ii)我们要检查 我们为CO提出的连接机制也适用于O2。(iii)我们 我想验证一下关于 金属中心的配位化学，以及外源性 配体进入，氧化还原反应性和热力学，以及偶联 氧化还原能转化为质子转移。 NiFe氢化酶。NiFe氢化酶的功能活性中心 含有固有的CN-和CO，也许是研究最多的振动 化学中的发色团这提供了一个机会， 光谱来解决结构和功能问题。其中包括： Ni和Fe的氧化态变化、电子结构和 各种形式的双核位点的立体化学，以及它们的 反应性期间的变化;是否可能是二氢或氢化物物种 重要;和其他氧化还原辅因子的身份。 全氯乙烯脱卤酶。最近，一种新的酶， 完成各种底物的还原脱卤，PCE 脱卤酶，已被分离和表征。这是一种可溶性的钴- Corrinoid蛋白与Fe-S簇作为氧化还原辅因子。我们想 利用Co-咕啉和Fe-S簇的拉曼和红外特征 为了探测这种氧化还原位点的结构和功能动力学， 酵素

The central objective of this project is to elucidate the fundamental factors involved in the function of redox metalloproteins. We want to understand how these proteins facilitate electron transfer and small molecule activation, how they exert kinetic or thermodynamic control, and how they conserve or utilize the energy of the processes that they catalyze. Our approaches emphasize vibrational spectroscopies which are sensitive to structure. In particular, we emphasize time-resolved vibrational probes. The following Specific Aims are proposed. Heme-Copper Oxidases. (i) We want to understand the differences among oxidases from different species. (ii) We want to check whether the ligation mechanisms that we have proposed for CO apply to O2. (iii) We want to test the hypothesis concerning the relationships between the coordination chemistry of the metal centers, and the control of exogenous ligand entry, redox reactivity and thermodynamics, and the coupling of redox energy to proton translocation. NiFe Hydrogenases. The functional active site of NiFe hydrogenases contains intrinsic CN- and CO, perhaps the most-studied vibrational chromophores in chemistry. This presents an opportunity to use vibrational spectroscopies to address structural and functional issues. These include: the oxidation state changes of Ni and Fe; the electronic structures and the stereochemistry of the binuclear site in various forms, and their changes during reactivity; whether dihydrogen or hydride species may be important; and the identity of other redox co-factors. Perchloroethylene (PCE) Dehalogenase. Quite recently a novel enzyme that accomplishes reductive dehalogenation of a wide range of substrates, PCE dehalogenase, has been isolated and characterized. This is a soluble Co- corrinoid protein with Fe-S clusters as redox cofactors. We want to exploit the Raman and infrared signatures of Co-corrins and Fe-S clusters to probe the structures and functional dynamics of the redox sites of this enzyme.