Infrared Spectroscopic Studies of Plant Photosynthesis

植物光合作用的红外光谱研究

• 批准号: 0842246
• 负责人: Bridgette Barry
• 金额: $ 64.66万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0842246&HistoricalAwards=false
• 关键词: Infrared; Spectroscopic; Studies; Plant; Photosynthesis

Protein dynamics play a key but poorly understood role in enzymatic mechanisms. The development of new methods to identify protein structural changes that facilitate chemical reactions will have a transformative effect on our understanding of biological catalysis. Photosynthetic reaction centers provide an example of biological reactions in which protein dynamics play an important role and in which the reactions are light-inducible. Therefore, the photosynthetic reactions serve as a model system in which kinetic mechanism can be investigated using laser flashes to synchronize and start reactions. To identify protein structural changes important in catalysis, novel, time-resolved spectroscopic studies of the oxygen-evolving complex (OEC) in photosystem II (PSII) will be conducted. PSII consists both of integral, membrane-spanning subunits and of extrinsic subunits. The OEC contains a tetranuclear manganese (Mn) cluster and accumulates the four photon-derived oxidizing equivalents necessary for oxygen production from water. The sequentially oxidized forms of the catalytic site are called the Sn states, where n refers to the number of oxidizing equivalents stored. Chloride plays an important but not completely understood role in the S state cycle. Despite decades of study, many aspects of the water oxidation mechanism remain to be elucidated. The intellectual merit of these activities is that new fundamental understandings of the role of protein dynamics in catalysis will result. The photosynthetic oxygen-evolving reactions are responsible for the maintenance of aerobic life on earth and thus are of intrinsic importance in biological chemistry. These reactions also serve as a model of other enzymatic reactions involving molecular oxygen. BROADER IMPACTS:The broader impact of these activities results from the advancement of teaching, training, and learning, as well as from broadening the scientific participation of underrepresented groups. The principal investigator has had the privilege of training individuals from underrepresented groups, including both graduate and undergraduate students. Several of the principal investigator's former students and postdoctoral associates have gone on to teach at undergraduate or Ph.D.-granting institutions. The principal investigator has collaborations with individuals who teach at non-Ph.D. granting institutions, and these individuals are co-authors with the principal investigator on publications, which have been broadly disseminated to the scientific community. In addition, the principal investigator is program director for a new Georgia Tech Molecular Biophysics training program, which will enhance the infrastructure for research and training at Georgia Tech. The principal investigator teaches at both the undergraduate and graduate levels at Georgia Tech, and she incorporates research and literature-based exercises in these courses. Further, the principal investigator has been involved in outreach to the community through science fair activities. Plans for the next funding cycle include broadening graduate and undergraduate student involvement in the Molecular Biophysics research program by outreach to historically black institutions in the Southeast and Atlanta area. Also, the principal investigator will recruit summer students through the NSF REU program in the summer and through Georgia Tech research opportunities during the academic year.

蛋白质动力学在酶促机制中起着关键但鲜为人知的作用。识别促进化学反应的蛋白质结构变化的新方法的发展将对我们对生物催化的理解产生革命性的影响。光合反应中心提供了一个生物反应的例子，其中蛋白质动力学起重要作用，并且反应是光诱导的。因此，利用激光同步和启动光合反应可以作为一个模型系统来研究光合反应的动力学机制。为了确定在催化过程中重要的蛋白质结构变化，将对光系统II （PSII）中氧进化复合物（OEC）进行新颖的、时间分辨的光谱研究。PSII由完整的跨膜亚基和外在亚基组成。OEC含有一个四核锰（Mn）团簇，并积累了从水中产生氧气所必需的四个光子衍生的氧化等价物。催化位点的顺序氧化形式称为锡态，其中n指存储的氧化等价物的数量。氯化物在S态循环中起着重要但尚未被完全理解的作用。尽管经过几十年的研究，水氧化机制的许多方面仍有待阐明。这些活动的智力价值在于，对蛋白质动力学在催化中的作用将产生新的基本理解。光合促氧反应负责维持地球上的需氧生命，因此在生物化学中具有内在的重要性。这些反应也可作为其他涉及分子氧的酶促反应的模型。更广泛的影响：这些活动的更广泛影响来自于教学、培训和学习的进步，以及扩大代表性不足群体的科学参与。首席研究员有幸从代表性不足的群体中培训个人，包括研究生和本科生。这位首席研究员以前的一些学生和博士后同事已经在本科或博士学位授予机构任教。首席研究员与非博士授课的个人合作。资助机构和这些个人是出版物的主要研究者的共同作者，这些出版物已广泛传播到科学界。此外，首席研究员还是佐治亚理工学院新分子生物物理学培训项目的项目主管，该项目将加强佐治亚理工学院研究和培训的基础设施。首席研究员在佐治亚理工学院教授本科和研究生课程，她在这些课程中结合了研究和基于文献的练习。此外，首席研究员还参与了通过科学博览会活动向社区推广的活动。下一个资助周期的计划包括扩大研究生和本科生对分子生物物理学研究项目的参与，向东南和亚特兰大地区历史上的黑人机构伸出援手。此外，首席研究员将在夏季通过NSF REU项目招募暑期学生，并在学年期间通过佐治亚理工学院的研究机会招募。