The dynamic structure and function of photosystem II in photosynthesis

我们的研究采用实验和计算相结合的方法来研究光合作用中能量转换的主要过程。光合作用为地球上所有形式的生命提供了几乎所有的能量。我们正在跟踪光合色素最初捕获光，光能转移到光化学反应中心（光系统），以及随后用于光合作用的电子转移，最终以化学形式存储光能。完成这一任务的光系统是由色素分子和嵌入蛋白质亚基复合体中的电子传递辅助因子组成的。我们在分子水平上理解能量转换如何发生的独特方法是使用计算机模拟所有步骤，包括色素和蛋白质中每个原子的动态运动。我们的蛋白质动态模型使我们能够看到当能量转换过程发生时，所有分子是如何移动和相互作用的。蛋白质分子的详细运动是光系统如何设法从吸收的光中获取能量，并以如此高的效率首先将其转化为电能，然后最终转化为化学能的关键部分。我们将我们的计算方法与强大的实验光谱研究相结合，相互补充。通过计算机模拟对实验数据进行模拟，可以了解反应中心函数的分子起源。我们的工作重点是光系统II，在光合作用中负责水的分裂和氧的进化的关键酶。除了了解这种重要的蛋白质复合物的功能外，我们还对描述控制其活性并保护其免受光诱导损伤的许多调节机制感兴趣。我们的基础研究也对未来发展生物基光伏器件生产清洁能源具有重要意义。

Our research uses a combination of experimental and computational approaches to investigate the primary processes of energy conversion in photosynthesis. Photosynthesis supplies almost all of the energy to all forms of life on Earth. We are following the initial capture of light by photosynthetic pigments, the transfer of the light energy to the photochemical reaction centers (photosystems) and the subsequent transfers of electrons that are used by photosynthesis to ultimately store the energy of light in chemical form. The photosystems which accomplish this task are made of pigment molecules and electron transport co-factors imbedded in a complex of protein subunits. Our unique approach to understanding how energy conversion occurs at a molecular level is to use computers to simulate all of the steps including the dynamic motions of every atom in both the pigments and the proteins. Our protein dynamic models allow us to see how all of the molecules move and interact as the process of energy conversion occurs. The detailed motions of the protein molecules are a key part of how the photosystems manage to hold onto the energy from the absorbed light and convert it with such high efficiency into first electrical energy and then finally chemical energy. We combine our computational approaches with powerful experimental spectroscopic investigations that complement each other. By using the computer simulations to model the experimental data we can understand the molecular origins of reaction center function. Our work focuses on photosystem II, the key enzyme responsible for the splitting of water and evolution of oxygen in photosynthesis. In addition to understanding how this important protein complex functions we are interested in characterizing the many regulatory mechanisms that control its activity and protect it from light induced damage. Our basic research is also important to future development of bio-based photovoltaic devices to produce clean energy.