Mechanism and Macromolecular Organization in Photosynthetic Reaction Centers

光合反应中心的机理和大分子组织

• 批准号: 8904134
• 负责人: Steven Boxer
• 金额: $ 31.8万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-15 至 1992-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8904134&HistoricalAwards=false
• 关键词: Mechanism; Macromolecular; Organization; Photosynthetic; Reaction

Biophysical studies of the mechanism of the initial charge separation steps in photosynthetic reaction centers (RC) will be continued. The recent X-ray structure determinations of RCs from two bacterial species has focused attention on the molecular mechanism of highly efficient electron transfer in this chromophore-protein assembly. Photoinduced electron transfer generates an intermediate which is a radical pair and has a large electric dipole moment. These two characteristics make possible the manipulation of the reaction dynamics by applied magnetic and electric fields, respectively. The initial charge separation and energy storage steps in photosynthesis take place in a membrane bound chlorophyll- protein complex called the photosynthetic reaction center. The RC is the smallest isolatable unit which carries out the initial charge separation steps of photosynthesis. The three dimensional structure of the RC from two species of purple non-sulfur bacteria have been determined to atomic resolution in the past several years. Although a great deal of spectroscopic and kinetic data had been obtained before the crystal structure was solved, the availability of the atomic coordinates of all the reactive components and their solvent has stimulated great interest in understanding the underlying physics of the RC function.

对光合反应中心（RC）初始电荷分离步骤机理的生物物理研究将继续进行。最近对两种细菌RCs的x射线结构测定将重点放在了这种发色团-蛋白质组装中高效电子转移的分子机制上。光致电子转移产生一种中间体，这种中间体是一个具有大电偶极矩的自由基对。这两个特性使得分别用外加磁场和电场来操纵反应动力学成为可能。光合作用中最初的电荷分离和能量储存步骤发生在一个被称为光合反应中心的膜结合的叶绿素-蛋白质复合体中。RC是完成光合作用初始电荷分离步骤的最小可隔离单元。近年来，对两种紫色无硫细菌的RC的三维结构进行了原子分辨率的测定。虽然在解决晶体结构之前已经获得了大量的光谱和动力学数据，但所有活性组分及其溶剂的原子坐标的可用性激发了人们对RC函数的潜在物理理解的极大兴趣。