Bacterial Reaction Centers With New Photochemical Properties

破译质子运动与电子转移相联系的机制是理解生化催化的一个重要挑战。亚利桑那州立大学的詹姆斯·艾伦和乔安·威廉姆斯教授正在努力阐明光合作用中发生的化学反应的这种联系。光合作用是自然界将光转化为化学能的基本过程。由于控制质子和电子转移之间的耦合对于实现有效的能量转换和化学转换至关重要，因此该项目旨在更全面地理解在复杂系统中管理这些过程的物理原理。这些活动通过扩大对科学的参与和更广泛社区的参与来提供社会效益。为了克服传统的低毕业率和对科学学位项目的有限参与，该项目为来自当地社区大学的学生提供个人研究体验，在一个鼓励他们继续从事科学的支持性环境中。在另一种参与方式中，学生们与艺术家合作，表达生物能源和光合作用研究背后的科学概念，并向当地社区展示他们的科学与艺术的整合。有了这个奖项，分子和细胞生物科学部分子生物物理学集群的部分共同资助的生命过程化学项目支持亚利桑那州立大学的詹姆斯·艾伦和乔安·威廉姆斯教授帮助建立分子概念，解释蛋白质如何有效地执行质子耦合的多电子转移反应。他们正在使用新的蛋白质设计策略来修饰细菌反应中心，细菌反应中心是一种完整的膜蛋白，作为光合作用中初级光化学的位置。质子和电子转移的产额是在不同的辅因子和蛋白质环境下测量的。这些实验方法结合了分子生物学和生化技术实现的基于结构的蛋白质设计，以及通过光学和磁共振光谱分析得到的复合体的性质。该项目旨在扩大可用于设计用于生物系统催化的质子耦合电子转移反应的工具，并建立适用于理解光系统II的基本水氧化反应中氧化态进展的框架。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Deciphering the mechanisms by which the movement of protons is linked to electron transfer is an important challenge in understanding biochemical catalysis. Professors James Allen and JoAnn Williams of Arizona State University are directing their efforts to elucidate this linkage for chemical reactions that occur in photosynthesis, nature's fundamental process for converting light into chemical energy. Because control of coupling between proton and electron transfer is critical for achieving efficient energy conversion and chemical transformations, this project aims to generate a more complete understanding of the physical principles that govern these processes in complex systems. The activities offer societal benefits through broadening participation in science and engagement of the wider community. To overcome traditional low graduation rates and limited participation in science degree programs, this project provides students from a local community college with a personal research experience in a supportive environment that encourages their continuation in science. In another avenue of engagement, students work with artists to express the scientific concepts behind research in bioenergy and photosynthesis and present their integration of science and art to the local community.With this award, the Chemistry of Life Processes Program, with partial co-funding from the Molecular Biophysics Cluster in the Division of Molecular and Cellular Biosciences, is supporting Professors James Allen and JoAnn Williams of Arizona State University to help establish molecular concepts that explain how proteins effectively perform proton-coupled, multi-electron-transfer reactions. They are using novel protein design strategies to modify the bacterial reaction center, an integral membrane protein serving as the site of the primary photochemistry in photosynthesis. The yields of proton and electron transfer are being measured for different cofactors and protein environments. The experimental methods combine structure-based protein design, enabled by molecular biology and biochemical techniques, with analysis of the properties of the resulting complexes by optical and magnetic resonance spectroscopy. The project is designed to expand the tools available for designing proton-coupled, electron-transfer reactions for catalysis in biological systems and establish a framework applicable for understanding the progression of oxidation states in the fundamental water oxidation reactions of photosystem II.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.