Bacterial Reaction Centers With New Photochemical Properties

该奖项由化学系的生命过程化学项目和分子和细胞生物科学系的分子生物物理组共同资助亚利桑那州立大学的James Allen教授和JoAnn Williams博士研究使光合作用有机体能够将光能转化为化学能的因素。该项目的总体目标是设计能够催化光诱导氧化反应的新型金属簇合物。他们和他们的合作者的实验室里有各种实验技术可以用来探测这种新型金属团簇的活性。这些研究旨在深入了解金属团簇执行复杂的多电子反应所需的条件，包括从水中生产分子氧。艾伦教授和威廉姆斯博士在使用蛋白质设计来回答有关光合作用反应的基本科学问题方面的研究，包括对科学研究的不同参与，包括本科生在化学/生物界面接触现代研究的一个重要因素。在所有光合作用系统中，初级能量传递事件是在光诱导下在色素-蛋白质复合体中产生电荷分离状态。详细的光谱研究和这些络合物的三维结构为理解它们的许多功能奠定了坚实的基础。然而，光系统II的锰团簇催化水氧化的基本生物过程的机制是该领域的一个主要悬而未决的问题。因此，本项目旨在剖析这一能力。细菌反应中心将作为一个平台，在一个明确定义的蛋白质环境中重建光系统II的锰簇的特征。对各种锰团簇的关键性质的表征将揭示金属团簇中促进氧化反应的共同基序。总体而言，从这些研究中获得的见解应该有助于建立分子概念，解释蛋白质中的锰辅因子如何有效地执行复杂的化学反应，并导致能够实现有益的光引导催化过程的新的生物系统的开发。

With this award, the Chemistry of Life Processes Program in the Division of Chemistry and the Molecular Biophysics Cluster in the Division of Molecular and Cellular Biosciences are jointly funding Professor James Allen and Dr. JoAnn Williams of Arizona State University to investigate the factors that give photosynthetic organisms the ability to convert light into chemical energy. The overall objective of this project is to engineer novel metal clusters that can catalyze light-induced oxidation reactions. A variety of experimental techniques are available in their laboratory and those of their collaborators to probe the activity of the novel metal clusters. The studies are directed at providing insight into the requirements needed for metal clusters to perform complex multi-electron reactions, including the production of molecular oxygen from water. The research of Professor Allen and Dr. Williams in using protein design to answer fundamental scientific questions about photosynthetic reactions and includes diverse participation in scientific research, including an important element of undergraduate exposure to modern research at the chemistry/biology interface.In all photosynthetic systems, the primary energy transduction event is the light-induced generation of a charge-separated state in a pigment-protein complex. Detailed spectroscopic studies and three-dimensional structures of these complexes form a firm foundation for understanding many of their functions. However, the mechanism by which the manganese cluster of photosystem II catalyzes the essential biological process of water oxidation is a major outstanding question in the field. Thus this project is directed towards dissecting this capacity. The bacterial reaction center will serve as a platform to recreate features of the manganese cluster of photosystem II in a well-defined protein environment. Characterization of key properties of a variety of manganese clusters would reveal common motifs in metal clusters that facilitate oxidation reactions. Overall, the insight gained from these studies should help establish molecular concepts that explain how manganese cofactors in proteins efficiently perform intricate chemical reactions, as well as lead to the development of novel biological systems that are capable of accomplishing beneficial light-directed catalytic processes.