Spectroscopic and Structural Studies of Primary Photochemical Processes in Photosynthesis

称为光系统I的光化学反应中心络合物的特点是存在作为电子受体的结合铁硫中心。光化学活性的天然光系统I复合物的制备包含至少十二个亚基，其中大多数没有明确的功能。该项目的总体目标是定义这些子单元的功能，并确定它们的结构组织。主要的实验技术将是生化分解和重构，这些方法将辅以生物物理测量来监测许多电子载体的功能状态。除了表征这个复合体，该项目还将考虑从厌氧光合细菌（称为绿硫细菌）中分离的反应中心复合体中多肽亚基的结构组织，因为有令人信服的生物物理证据表明该复合体具有与植物型光系统I复合体相似的功能成分。该项目的结果将有助于确定光化学反应中心复合物中光诱导电子转移的机制，并将提供光合反应中心复合物从原始系统到更先进系统的演变信息。

The photochemical reaction center complex known as Photosystem I is characterized by the presence of bound iron-sulfur centers that function as electron acceptors. Preparations of the photochemically active native Photosystem I complex contains at least one dozen subunits, most of which have no well established function. The overall objective of this project is to define the function of these subunits and to determine their structural organization. The major experimental techniques will be those of biochemical resolution and reconstitution and these methods will be supplemented with biophysical measurements to monitor the functional state of many of the electron carriers. In addition to characterizing this complex, the project will also consider the structural organization of polypeptide subunits in a reaction center complex isolated from anaerobic photosynthetic bacteria known as green sulfur bacteria since there is compelling biophysical evidence that indicates this complex has functional components that are similar to those in the plant-type Photosystem I complex. Results from this project will aid in defining the mechanism of photoinduced electron transfer in a photochemical reaction center complex and will provide information on the evolution of the photosynthetic reaction center complex from primitive to more advanced systems.