Dynamics in Photosynthetic Oxygen Evolution

太阳能发电有能力满足世界日益增长的能源需求。在植物和藻类中，自然的光合作用利用光能从水中去除电子形成氧气，然后将电子引导到为细胞提供动力的生化反应中。这项由NSF资助的研究项目将为进行光合氧生产所需的化学步骤提供新的见解。特别是，将获得有关光系统II蛋白复合物如何结合和激活水的信息，沿着该过程中其他参与者如钙、氯化物所起的作用。许多不同的光谱方法将被用来研究这种光诱导的水氧化循环。为了帮助解释光谱，蛋白质将被修饰为含有非天然氨基酸，这些氨基酸将作为结构和功能的独特探针。该项目的智力价值是对光合作用水氧化过程有了更全面的了解，这将为新的设计战略奠定基础，以满足全球对廉价和可再生能源的迫切需求。研究活动将促进处于不同培训阶段和来自不同类型学术环境的代表性不足群体的教学、培训和学习。水分解过程由叶绿素的光驱动激发启动。该事件引起跨膜的电荷分离。这种电子转移是由一系列电子受体逐步介导的，并导致太阳能的守恒。水分解反应在光合反应中心光系统II中由锰钙金属簇和氧化还原活性酪氨酸残基催化。光系统II由多个蛋白质亚基组成。一种称为PsbO，是一种内在无序的蛋白质，它与氯沿着在促进催化中起着重要作用。氧释放循环涉及协调的光驱动过程，其中带负电荷的电子和带正电荷的质子从与金属中心结合的水中去除。自然光合作用的一个关键特征是利用阳光氧化水。利用水作为电子源的人工系统将提供负担得起的可持续燃料生产。为了理解光合水氧化化学，有必要破译光驱动的质子和电子转移反应的精确协调。此外，功能的作用，内在无序的亚基，PsbO，钙，和氯必须阐明。这项工作包括代表性不足的群体参与科学，以及与非博士授予学院的合作，包括一所历史上的黑人女子学院。

Solar power has the capacity to meet the world's increasing needs for energy. In plants and algae, natural photosynthesis uses light energy to remove electrons from water to form oxygen, and then directs the electrons to biochemical reactions that power the cell. This NSF funded research project will give new insight into the chemical steps necessary to carry out photosynthetic oxygen production. In particular, information will be gained about how the photosystem II protein complex binds and activates water, along with the roles played by other participants in the process such as calcium, chloride. Many different spectroscopic approaches will be employed to study this light-induced water oxidation cycle. To help interpret the spectra, the proteins will be modified to contain non-natural amino acids that will serve as unique probes of structure and function. The intellectual merit of this project is a more complete understanding of the photosynthetic water oxidation process, which will lay the groundwork for new design strategies to address the pressing global need for inexpensive and renewable sources of energy. The research activities will advance the teaching, training, and learning of underrepresented groups who are at different stages of training and from different types of academic settings.The water splitting process is initiated by light-driven excitation of chlorophyll. This event causes a charge separation across a membrane. This electron transfer is mediated stepwise by a chain of electron acceptors and leads to the conservation of solar energy. The water splitting reaction is catalyzed in the photosynthetic reaction center, photosystem II, by a manganese-calcium metal cluster and a redox-active tyrosine residue. Photosystem II consists of multiple protein subunits. One, termed PsbO, is an intrinsically disordered protein, which, along with chloride, plays an important role in facilitating catalysis. The oxygen-evolving cycle involves a coordinated light-driven process, in which negatively charged electrons and positively charged protons are removed from water bound to the metal center. A critical feature of natural photosynthesis is the use of sunlight to oxidize water. Artificial systems, which use water as an electron source, would provide affordable and sustainable fuel production. To understand photosynthetic water oxidation chemistry, it is necessary to decipher the precise coordination of light-driven proton and electron transfer reactions. Also, the functional role of the intrinsically disordered subunit, PsbO, calcium, and chloride must be elucidated. The work includes participation by underrepresented groups in science and collaborations with non-PhD granting colleges, including an historically black college for women.