Time Resolved EPR Studies of Natural and Artificial Photosynthesis

拟议研究的目标是获得对自然和人工光合系统中控制太阳能转换效率的因素的基本理解。我们的一套现代时间分辨电子顺磁共振（EPR）仪器使我们能够测量与能量转换相关的电子自旋极化，并使用它来详细研究这一过程的初始步骤。我们与美国，德国，俄罗斯和日本的团队密切合作，使我们能够获得广泛的互补光谱，理论，生化和分子生物学技术。使用这些广泛的方法，我们将这些至关重要的系统的能量学、动力学和动力学的精细细节组合在一起。我们现在正在利用这些知识来帮助设计和表征自然系统的人工模拟。***对天然光合蛋白的研究主要集中在两个方面：***(i)光诱导电子转移的途径和能量学的研究***(ii)氧敏感生物中复合物结构的测定。在人工光合作用领域，我们正在开发两种主要类型的系统：***(i)能够分解水的光化学电池。***(ii)生物杂化复合物，其中天然蛋白质经过化学修饰以产生光系统模拟物***凭借我们独特的生物化学和光谱技术以及自旋化学专业知识的结合，我们希望在解决这些问题方面取得重大进展，这对于充分理解光化学能量转换的效率至关重要

The goal of the proposed research is to gain a fundamental understanding of the factors governing the efficiency of solar energy conversion in natural and artificial photosynthetic systems. Our suite of modern time resolved electron paramagnetic resonance (EPR) instruments allows us to measure the electron spin polarization associated with the energy conversion and to use it to study the initial steps of this process in detail. Our close collaborations with groups in the US, Germany, Russia and Japan give us access to a wide range of complementary spectroscopic, theoretical, biochemical and molecular biology techniques. Using this broad array of methods, we are putting together an exquisitely detailed picture of the energetics, kinetics and dynamics of these vitally important systems. We are now using this knowledge to aid in the design and characterization of artificial mimics of the natural systems. ***The studies of natural photosynthetic proteins focus on two main areas: ***(i) Investigations of the pathway and energetics of light-induced electron transfer ***(ii) Determination of the structure of the complexes in oxygen sensitive organisms. ***In the area of artificial photosynthesis we are developing two main types of systems:***(i) Light-driven, photochemical cells, which are able to split water. ***(ii) Biohybrid complexes in which natural proteins are chemically modified to create photosystem mimics***With our unique combination of biochemical and spectroscopic techniques and expertise in spin chemistry we expect to make significant progress in resolving these issues, which are critical to a full understanding of the efficiency of photochemical energy conversion.**