Spectroscopic and Structural Studies of Primary Photochemical Processes in Photochemical Processes in Photosynthesis

光化学反应中心是光合作用膜上吸收的光能转化为化学能的场所。虽然最近的生化证据支持光系统II和细菌反应中心之间的结构相似，但光系统I(PSI)反应中心复合体中的成分仍然定义得比较模糊。只是在过去的几年里，才有了具有良好特征的高等植物PSI制剂，它们保留了PSI在体内的结构和功能方面。放氧生物体的PSI反应中心复合体是本项目的重点，尽管已知它与其他复合体在功能上不同，因为它包含一个低电势电子受体系统，但它的特征不太好。马尔金博士将研究分离的PSI复合体中多肽亚基的性质，以及特定电子转移载体与特定亚基的关联。还将定义复合体中各个亚基的化学计量比以及这些亚基含量随环境信号的变化。

The photochemical reaction center is the site in the photosynthetic membrane where absorbed light energy is converted into chemical energy. While recent biochemical evidence has supported the structural similarity between photosystem II and the bacterial reaction center, components in the photosystem I (PSI) reaction center complex remain more poorly defined. It is only in the past several years that well-characterized higher plant PSI preparations which retain the structural and functional aspects of PSI in vivo have been available. The PSI reaction center complex of oxygen-evolving organisms, which is the focal point of the current project, is less well characterized although it is known to be functionally different than the other complexes since it contains a low potential electron acceptor system. Dr. Malkin will examine the nature of the polypeptide subunits in the isolated PSI complex and the association of specific electron transfer carriers with specific subunits. The stoichiometry of the individual subunits within the complex and changes in the content of these subunits in response to environmental signal will also be defined.