IRON-SULFUR PROTEINS AS BOUND ELECTRON CARRIERS

铁硫蛋白作为结合电子载体

• 批准号: 3270093
• 负责人: RICHARD MALKIN
• 金额: $ 18.24万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-07-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3270093
• 关键词: Chlorophyta; Rhodopseudomonas; binding proteins; biological signal transduction; chemical structure function; chloroplasts; complementary DNA; cytochrome b; cytochrome c; cytochromes; electron spin resonance spectroscopy; electron transport; enzyme inhibitors; genetic manipulation; hemoprotein structure; iron; iron sulfur protein; liposomes; membrane permeability; metalloproteins; point mutation; protein engineering; protein reconstitution; quinones; transport proteins

Energy transduction in biological systems involves the translocation of protons across a membrane to generate a proton motive force that is used for the synthesis of ATP. How protons are moved across this membrane remains a central problem in bioenergetics. The cytochrome b-c complex couples electron transport from reduced quinones to high potential electron acceptors to proton translocation in mitochondrial, bacterial and chloroplasts membranes. In complexes from all these membranes, two b-cytochromes, one ccytochrome and a Rieskatype iron- sulfur protein are present. An associated quinone is usually also found in these complexes. This project focuses on the role of the Rieske ironsulfur protein in the function of the cytochrome b-c complex with particular emphasis on how this protein interacts with quinone molecules. Factors which are involved in quinone and Rieske protein binding will be considered using the biochemical techniques of resolution and reconstitution. The mode of interaction of inhibitors which are quinone analogs will also be examined. The role of lipids in these interactions will receive particular attention. The mechanism of electron transfer and associated proton translocation will be examined from a kinetic standpoint using liposome incorporated cytochrome complex in conjunction with homologous photosystem complexes for light activation. This allows for control of the electon flow into and out of the complex. In addition to these biochemical approaches, studies of specifically altered cytochrome complexes, either generated by the isolation of inhibitorinsensitive mutants or produced using sitedirected mutagenesis of isolated genes, will be done in an attempt to define specific regions of individual proteins, such as the Rieske protein, that are involved in specified functions of the complex. These studies are aimed at elucidating structural and organizational features which influence the function of a bound iron-sulfur protein that is involved in a basic cellular process, the generation of the energy required for the synthesis of ATP.

生物系统中的能量转换涉及 质子穿过细胞膜而产生质子 用于合成ATP的动力。 质子如何 穿过这层膜仍然是一个中心问题， 生物能量学 细胞色素b-c复合物耦合电子 从还原醌到高电位电子的传递 线粒体、细菌和 叶绿体膜。 在所有这些膜的复合物中， 两个b细胞色素，一个c细胞色素和一个Rieskatype铁- 存在硫蛋白。 缔合醌通常也是 在这些复杂的。 本项目侧重于 Rieske铁硫蛋白在细胞色素b-c中的作用 特别强调这种蛋白质如何与 与醌分子。 参与醌的因素 和Rieske蛋白结合将被考虑使用 拆分和重组的生化技术。 的 醌类似物抑制剂的相互作用模式将 也要检查。 脂质在这些相互作用中的作用将 受到特别关注。 电子转移机理 和相关的质子易位将从一个 脂质体掺入细胞色素动力学观点 与同源光系统复合物结合的复合物 用于光激活。 这允许控制电子流 进出大楼 除了这些生化 方法，特别是改变细胞色素复合物的研究， 或者是通过分离大肠杆菌或不敏感突变体产生的 或使用分离基因的定点诱变产生， 试图定义个体的特定区域， 蛋白质，如Rieske蛋白，参与特定的 复杂的功能。 这些研究旨在阐明 结构和组织特征，影响 一种结合铁硫蛋白的功能， 细胞过程，产生的能量所需的 合成ATP。