Primary Electron Transfer Processes in Photosynthetic Bacterial Reaction Centers

对基本了解细菌光合作用反应中心(RCS)中电荷分离过程的关键问题将使用野生型RCS、具有定点突变的RCS和经过化学修饰以移除或改变特定辅因子的RCS的时间分辨吸收光谱来研究。霍尔滕博士计划研究RC假体基团参与电子转移的细节，并开辟蛋白质在电荷分离过程中静态和动态作用的新领域。反应中心是光合作用有机体的光化学心脏。这种结合在膜上的色素-蛋白质复合体的功能是将光能转化为化学能。自从细菌Rb的RC以来，了解RC如何在光合作用中发挥其独特的作用一直是人们努力的主题。球藻在大约20年前被分离出来。最近，由于从RPS解出了RC复合体的三维结构，研究和了解细菌RC的内部性质和操作的能力取得了巨大的飞跃。绿色的。因此，RC初级光化学的光谱研究被重新聚焦到更详细和更基本的水平上，同时具有比以往任何时候都广泛得多的意义。计划中的研究将产生各种信息，这些信息不仅对于阐明RC发挥作用的分子机制至关重要，而且还将促进电子转移、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.