Time Resolved EPR Studies of Natural and Artificial Photosynthesis

这项拟议研究的目标是从根本上了解在自然和人工光合作用系统中影响太阳能转换效率的因素。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补充光谱、理论、生化和分子生物学技术。使用这种广泛的方法，我们正在对这些极其重要的系统的能量学、动力学和动力学进行一幅极其详细的图景。我们现在正在利用这一知识来帮助设计和描述人工模拟自然系统。*天然光合作用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)氧敏感生物中复合体的结构测定。*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)光驱动的光化学电池，它能够分解水。*(Ii)对天然蛋白质进行化学修饰以产生光系统模拟物的生物杂化复合体*通过我们独特的生化和光谱技术以及自旋化学专业知识的结合，我们预计将在解决这些问题方面取得重大进展，这些问题对于全面了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.**