Bacterial Reaction Centers with New Photochemical Properties

生命科学化学计划资助亚利桑那州立大学的詹姆斯艾伦教授进行题为“具有新的光化学性质的细菌反应中心”的研究。“在所有光合系统中，主要的能量转换事件是光诱导色素蛋白复合物中电荷分离状态的产生。 虽然生物体之间的具体途径各不相同，但一般模式是非常保守的，对这些过程的理解是目前模拟光合作用过程的人工系统设计的基础。 来自球形红细菌的反应中心可以用作模型系统，以结合光系统II的特征，例如高度氧化的初级供体。 最近开发的氧化还原活性单核锰辅因子提供了机会，研究新的锰辅因子，并引入新的光驱动反应到这个光系统。所提出的研究的第一个目标是设计新的Mn辅因子，并将这些辅因子的性质与不同的实验观测值相关联。 第二个目标是使用这个模型系统来探测光系统II的Mn4Ca簇的关键特性，光系统II是水氧化的位点。 总的来说，从这些研究中获得的分子洞察力应该对开发金属酶的设计原则，理解光合作用中的电子转移机制以及改进能量转换技术产生普遍影响。 我们的研究通过提供更广泛的参与本科研究的机会来促进科学进步，通过编写教科书来应对本科教育的挑战，为新的跨学科研究生课程创建课程，促进与公众的科学交流，并为科学研究机会有限的学生提供赞助外展工作。该项目正在接受分子和细胞生物科学部生物分子动力学，结构和功能集群的共同资助。

The Chemistry of Life Sciences Program funds Professor James Allen of Arizona State University for research entitled "Bacterial Reaction Centers with New Photochemical Properties." In all photosynthetic systems, the primary energy transduction event is the light-induced generation of a charge-separated state in a pigment-protein complex. Although the specific pathways vary among organisms, the general pattern is remarkably conserved, and an understanding of these processes serves as the basis for current designs of artificial systems that mimic the photosynthetic process. The reaction center from Rhodobacter sphaeroides can be used as a model system to incorporate features of photosystem II such as a highly oxidizing primary donor. The recent development of a redox active mononuclear Mn cofactor provides the opportunity to study novel manganese cofactors and to introduce new light-driven reactions into this photosystem. The first objective of the proposed research is to design novel Mn cofactors and correlate the properties of these cofactors with different experimental observables. The second objective is to use this model system to probe key properties of the Mn4Ca cluster of photosystem II that is the site of water oxidation. Overall, the molecular insight gained from these studies should have a general impact on developing design principles for metalloenzymes, understanding electron transfer mechanisms in photosynthesis, and improving energy conversion technologies. Our research promotes progress in science by providing wider opportunities for participation in undergraduate research, meeting challenges in undergraduate education by writing textbooks, creating a curriculum for a new interdisciplinary graduate program, fostering scientific communication to the general public, and sponsoring outreach efforts to students who have limited opportunities for scientific research. This project is receiving co-funding from the Biomolecular Dynamics, Structure and Function Cluster in the Division of Molecular and Cellular Biosciences.