Primary Electron Transfer Processes in Photosynthetic Bacterial Reaction Centers

对于获得细菌光合反应中心（RCs）电荷分离过程的基本理解的关键问题将使用野生型RCs，具有位点定向突变的RCs和化学修饰以去除或改变特定辅因子的RCs的时间分辨吸收光谱进行研究。Holten博士计划研究RC假体在电子转移中所涉及的细节问题，并在蛋白质在电荷分离过程中的静态和动态作用方面开辟新的领域。反应中心是光合生物的光化学心脏。这种膜结合的色素蛋白复合物的功能是将光能转化为化学能。了解RC如何在光合作用中发挥其独特的作用，自从RC从细菌Rb中分离出来以来，一直是人们努力的主题。球形虫大约在20年前被分离出来。最近，研究和理解细菌RC的内部性质和运作的能力由于Rps的RC复合物的三维结构的解决而取得了巨大的飞跃。冬青。因此，RC初级光化学的光谱学研究已重新集中到更详细和基本的水平，同时具有比以往更广泛的意义。计划中的研究将产生多种信息，这些信息不仅对阐明RC功能的分子机制至关重要，而且还将推进电子转移、色素-蛋白质相互作用和蛋白质动力学领域的知识。

Issues which are key to obtaining a fundamental understanding of the charge separation process in bacterial photosynthetic reaction centers (RCs) will be investigated using time-resolved absorption spectroscopy of wild-type RCs, RCs having site- directed mutations and RCs chemically modified to remove or alter a specific cofactor. Dr. Holten plans to study unresolved issues on the details of the involvement of the RC prosthetic groups in electron transfer and open up new frontiers on the role of the protein, both static and dynamic, in the charge separation process. The reaction center is the photochemical heart of a photosynthetic organism. The function of this membrane-bound pigment-protein complex is to transform light energy into chemical energy. Understanding how the RC carries out its unique role in photosynthesis has been the subject of intense effort since the RC from the bacterium Rb. sphaeroides was isolated about 20 years ago. Recently the ability to investigate and understand the internal properties and operation of the bacterial RC took a quantum leap forward as a result of the solution of the three-dimensional structure of the RC complex from Rps. viridis. Spectroscopic studies of the RC primary photochemistry have thus been refocused to a more detailed and fundamental level and at the same time have taken on a much broader significance than ever before. The studies planned will yield diverse information that is critical not only for elucidating the molecular mechanisms by which the RC functions, but, also, will advance knowledge in the areas of electron transfer, pigment-protein interactions and protein dynamics.