US-Switzerland Cooperative Research: Photosynthetic Electron Transfer Reactions

该奖项为德克萨斯理工大学的David B. Knaff博士提供了适度的支持，以促进对瑞士苏黎世大学的长期研究访问。在那里，他将与生物化学研究所的Hans R. Bosshard教授和植物生物学研究所的Reinhard Bachofen教授在两条研究方向上合作。这两个合作项目都是Knaff博士当前研究的逻辑延伸；然而，他的实验室没有足够的设备来单独进行某些方面的工作。与Bosshard教授的合作重点是阐明两种植物电子转移蛋白铁氧还蛋白和铁氧还蛋白之间的静电稳定复合物：NADP+氧化还原酶（FNR）的细节。FNR是所有进化氧气的光合生物光合电子传递链的关键酶。化学修饰的特定氨基酸基团将被用来确定带电基团参与保持两个蛋白质在一起。针对FNR上不同位点制备的抗体将用于鉴定FNR上不同结构域在催化铁氧还蛋白向NADP+的电子转移中的具体作用。铁还氧蛋白：FNR复合物的详细几何特征可能为其他铁还氧蛋白：酶复合物的可能结构提供线索。它也可能为哺乳动物代谢中相关蛋白质复合物的功能提供见解。boshard教授拥有最先进的蛋白质测序设备，他在使用差异化学修饰技术识别蛋白质复合物形成过程中涉及的特定氨基酸残基方面是公认的世界领先者。与巴霍芬教授的合作将侧重于识别绿红假单胞菌在有氧和光合条件下生长时电子传递链中一个区域携带电子的蛋白质成分的变化。近年来，人们对这种紫色无硫光合细菌的电子传递链越来越了解。然而，人们对呼吸链的了解远远少于对光合作用电子传递链的了解。光合紫色细菌的电子流与线粒体、叶绿体和蓝藻之间的相似之处增加了这项工作的潜在相关性和意义。巴霍芬教授的团队为培养光合细菌提供了有价值的、最先进的计算机控制设备，并在这种细菌的分子生物学方面提供了专业知识。

This award provides modest support to Dr. David B. Knaff of Texas Tech University to facilitate a long term research visit to the University of Zurich, Switzerland. There he will collaborate in two lines of research with Professor Hans R. Bosshard of the Biochemistry Institute and Professor Reinhard Bachofen of the Plant Biology Institute. Both collaborative projects represent logical extensions of Dr. Knaff's current research; however, his laboratory is not adequately equipped to carry out certain aspects of the work alone. Collaboration with Professor Bosshard centers on elucidating the details of an electrostatically stabilized complex between two plant electron transfer proteins, ferredoxin and ferredoxin:NADP+ oxidoreductase (FNR). FNR is a key enzyme of the photosynthetic electron transfer chain of all oxygen-evolving photosynthetic organisms. Chemical modification of specific amino acid groups will be employed to identify the charged groups that are involved in holding the two proteins together. Antibodies prepared against different sites on FNR will be used to identify the specific roles of different domains on FNR in catalyzing electron transfer from ferredoxin to NADP+. Characterization of the detailed geometry of the ferrodoxin:FNR complex may provide clues to the likely configuration of other ferrodoxin:enzyme complexes. It may also provide insights into the functioning of related protein complexes in mammalian metabolism. Professor Bosshard has state-of-the-art facilities for protein sequencing and he is an acknowledged world-leader in using the technique of differential chemical modification to identify specific amino acid residues involved in the formation of protein complexes. Collaboration with Professor Bachofen will focus on identifying changes in electron-carrying protein constituents in one region of the electron transfer chain of Rhodopseudomonas viridis that occur when the bacterium is grown under aerobic versus photosynthetic conditions. The electron transfer chains of such photosynthetic purple non-sulfur bacteria have become increasingly better understood in recent years. However, much less is known about the respiratory chain than about its photosynthetic electron transfer chain. Resemblances between electron flow in photosynthetic purple bacteria and in mitochondria, chloroplasts and cyanobacteria increase the potential relevance and significance of this work. Professor Bachofen's group offers valuable state-of-the-art computer-controlled apparatus for growing photosynthetic bacteria and expertise in the molecular biology of such bacteria.