Electron Flow in Photosynthetic Bacteria

本项目的具体目标是（1） 表征光合作用的细胞色素bc1复合物 紫色非硫细菌的共振拉曼光谱 并表征复合物上的结合位点， 醌、细胞色素c2和抑制剂抗霉素A和（2） 为了比较细胞色素bc1复合物和其可溶性 紫色硫细菌细胞色素c电子受体 与紫色非硫细菌相比较。此外，为了比较 这些细胞色素bc1复合物的光谱性质 与功能类似的叶绿体细胞色素b6f 复杂. 重点放在生物能量学的独特方面， 这些细菌或在这些过程的简单性 细菌相比，类似的线粒体 呼吸 许多光谱（例如，共振 拉曼和电子顺磁共振光谱）， 生物化学的（例如，特定氨基的化学修饰 酸和光亲和标记）和遗传技术将 试图提供分子水平的细节， 这些电子转移反应， 光合细菌能量转换的核心。 %%% 细胞新陈代谢所需的能量产生 通过不同的机制。 在本研究中， 与电化学梯度相关的电子传递将 在光合细菌中进行研究。 这是一 方便的实验系统，因为电子转移可以 通过打开或关闭灯来启动和停止。

The specific objectives of this project are (1) to characterizethe cytochrome bc1 complex of a photosynthetic purple non-sulfur bacterium by resonance Raman spectroscopy and to characterize the binding sites on the complex for quinone, cytochrome c2 and the inhibitor antimycin A and (2) to compare the cytochrome bc1 complex and its soluble cytochrome c electron acceptor in apurple sulfur bacterium with those of purple non-sulfur bacteria. Also to compare the spectroscopic properties of these cytochrome bc1 complexes with the functionally analogous chloroplast cytochrome b6f complex. Emphasis is placed on unique aspects of bioenergetics in these bacteria or on the simplicity of processes in these bacteria compared to the analogous one in mitochondrial respiration. A number of spectroscopic (e.g., resonance Raman and electron paramagnetic resonance spectroscopy), biochemical (e.g., chemical modification of specific amino acids and photoaffinity labeling) and genetic techniques will be utilized in an attempt to provide details at the molecular level about these electron transfer reactions that are central to energy transduction in photosynthetic bacteria. %%% The energy needed for cell metabolism is generated through several different mechanisms. In this study, electron transport linked to an electrochemical gradient will be studied in a photosynthetic bacterium. This is a convenient experimental system because electron transfer can be started and stopped by turning light on or off.