Primary Processes in Heliobacterial Reaction Center

幽门螺杆菌反应中心的初级流程

• 批准号: 9106685
• 负责人: Robert Blankenship
• 金额: $ 27.8万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9106685&HistoricalAwards=false
• 关键词: Primary; Processes; Heliobacterial; Reaction; Center

The heliobacteria, a newly discovered family of non-oxygen evolving photosynthetic bacteria, have a reaction center that is broadly similar to Photosystem I of oxygen evolving organisms. The goal of this project is to develop the heliobacteria as a bacterial model for Photosystem I in the same way that the purple photosynthetic bacterial have been very successfully used as a model for Photosystem II. Dr. Blankenship isolated the reaction center from Heliobacillus mobilis in an active form,, and is characterizing its chemical and physical properties using a variety of techniques. Preliminary femtosecond absorption difference spectra suggest that a 670 nm absorbing species is not the primary electron acceptor in the heliobacteria, in contrast to reports from other laboratories. Experiments are proposed to identify the chemical nature of the primary acceptor. Redox titrations indicate that a species that undergoes two electron reduction under some conditions is an early acceptor. This species is probably a menaquinone, analogous to the phylloquinone acceptor A1 in Photosystem I. Experiments are proposed to characterize this acceptor, as well as subsequent Fe-S protein acceptors. The properties of the membrane-bound cytochrome that acts as electron donor to the reaction center will also be investigated.

日光细菌是一个新发现的非产氧光合细菌家族，其反应中心与产氧生物的光系统 I 大致相似。 该项目的目标是开发日光细菌作为光系统 I 的细菌模型，就像紫色光合细菌已非常成功地用作光系统 II 的模型一样。 Blankenship 博士以活性形式从运动Heliobacillus mobilis 中分离出反应中心，并使用多种技术表征其化学和物理特性。 与其他实验室的报告相反，初步的飞秒吸收差异光谱表明 670 nm 吸收物质不是日光细菌中的主要电子受体。 提议进行实验来鉴定主要受体的化学性质。 氧化还原滴定表明在某些条件下经历两个电子还原的物质是早期受体。 该物种可能是甲基萘醌，类似于光系统 I 中的叶绿醌受体 A1。建议通过实验来表征该受体以及后续的 Fe-S 蛋白受体。 还将研究充当反应中心电子供体的膜结合细胞色素的特性。