Studies of the Primary Reactions of Bacterial Photosynthesis

本研究的主要目的是了解细菌光合作用反应中心的L和M多肽在确定反应中心生色团之间的电子转移参数中所起的作用。为此，复杂的光谱技术将与这些多肽的氨基酸序列的分子遗传操作相结合，用于分析反应中心的功能。采用的具体方法包括皮秒分辨荧光衰减测量、电子转移中间体的亚皮秒分辨瞬变吸收光谱、反应中心基因的盒式诱变，以及通过迫使一个生物体的反应中心基因的缺失被来自相关生物体的反应中心序列修复而产生嵌合反应中心。这项工作将导致更好地理解光合作用主要事件中涉及的特定电子转移反应，并为一般蛋白质的介电性质提供新的见解。

The primary goal of this research is to gain insight into the role that the L and M polypeptides of the bacterial photosynthetic reaction center play in determining the parameters of electron transfer between reaction center chromophores. To this end, sophisticated spectroscopic techniques will be combined with molecular genetic manipulation of the amino acid sequences of these polypeptides for the analysis of reaction center function. Specific methods to be employed include picosecond resolution fluorescence decay measurements, subpicosecond resolution transient absorption spectroscopy of electron transfer intermediates, cassette mutagenesis of reaction center genes, and the production of chimeric reaction centers by forcing deletions in the reaction center genes of one organism to be repaired by reaction center sequences derived from a related organism. This work will result in a better understanding of the specific electron transfer reactions involved in the primary events of photosynthesis and provide new insights into the dielectric nature of proteins in general.