STRUCTURE & DYNAMICS OF FREE & COMPLEXED CYTOCHROMES C

结构

• 批准号: 2178147
• 负责人: A. JOSHUA WAND
• 金额: $ 11.8万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-01-01 至 1999-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2178147
• 关键词: Rhodospirillales; cytochrome c; cytochromes; electron transport; enzyme complex; heme; lipids; molecular dynamics; nuclear magnetic resonance spectroscopy; oxidation reduction reaction; protein folding; protein structure function

Electron transfer reactions between proteins control the generation, flow and use of energy in biological systems. Central to many of the processes involved in these events are the cytochromes c. A major goal of this proposal is to contribute to the understanding of the solution structure and dynamics of cytochrome c both free and in complex with biologically relevant structures such as protein redox partners and lipid. The studies described here will augment, unify and clarify a wide body of information regarding the function of this essential protein. Studies are proposed to take advantage of our recently determined high resolution models for the structure cytochrome c in its two redox states in order to directly and comprehensively test a variety of theoretical treatments of cytochrome c mediated electron transfer and to also provide a template for the interpretation of emerging studies of the dynamics of this protein. These efforts lead naturally to quantification of the structural and dynamic consequences of mutations of the cytochrome c molecule that affect stability, redox potential and other important physical parameters of the protein. The complex between cytochrome c and cytochrome b5 and the structural changes that occur upon association of cytochrome c with lipid will also be examined. In a major redirection of this grant we have initiated two exciting new projects. One is centered on taking advantage of the ability for facile mutagenesis of R. capsulatus cytochrome c2 in an effort to identify fleetingly populated folding intermediates by pulsed hydrogen exchange labeling. Parallel to these studies will be the determination of the folding pathway of apocytochrome b562 from the unfolded to the molten globule state. These two folding subprojects will hopefully get at the next issue in protein folding: the underlying themes defining folding pathways. The second new project is an effort to push the use of protein design and engineering to construct minimalist proteins which encaspuslate the essential features of various electron transfer proteins. These systems, termed maquettes, offer an simplified environment within which fundamental issues of inter- and intraprotein electron transfer can be probed. All of these studies will bear directly upon the biological function of the cytochrome class of proteins and will contribute to the understanding of the properties governing electron transfer within and between proteins in general. These studies will make extensive use of modern multinuclear and multidimensional NMR spectroscopy, a variety of methods for the determination of the solution structures of proteins to high resolution, and will also employ detailed analysis of NMR relaxation and hydrogen exchange phenomena to quantitate internal motion in these systems.

蛋白质之间的电子转移反应控制着产生，流量 并在生物系统中使用能量。许多过程的中心 这些事件涉及的是细胞色素c。一个主要目标 建议是为理解解决方案结构做出贡献 和细胞色素c的动力学既免费又具有生物学上的复杂性 相关结构，例如蛋白质氧化还原伙伴和脂质。研究 这里描述的将增强，统一和澄清广泛的信息 关于这种必需蛋白的功能。提出了研究 利用我们最近确定的高分辨率模型 在其两个氧化还原状态下结构细胞色素c，以直接和 全面测试细胞色素c的多种理论治疗 介导的电子传输，还为 解释该蛋白质动力学的新兴研究。这些 努力自然导致量化结构和动态 影响的细胞色素C分子突变的后果 稳定性，氧化还原电位和其他重要的物理参数 蛋白质。细胞色素C和细胞色素B5和 细胞色素c与脂质缔合后发生的结构变化 也将被检查。 在重新定向这笔赠款的重大方向中，我们发起了两个令人兴奋的新事物 项目。一个以利用便利的能力为中心 Capsulatus细胞色素C2的诱变，以识别 脉冲氢交换的人口转运折叠中间体 标签。与这些研究平行的将是确定 从展开到熔融 球状态。这两个折叠式下调希望能够达到 蛋白质折叠的下一个问题：定义折叠的基础主题 途径。第二个新项目是努力推动蛋白质的使用 设计和工程以构建简约蛋白质的设计和工程 各种电子转移蛋白的基本特征。 这些 系统，称为maquettes，提供了一个简化的环境 脑内和肾上腺内电子转移的基本问题可以是 探测。 所有这些研究都将直接遵循 细胞色素类蛋白质，将有助于理解 蛋白质内部和之间管理电子传输的性质 一般来说。这些研究将广泛使用现代多核 和多维NMR光谱，多种方法 确定蛋白质的溶液结构至高分辨率， 并将对NMR松弛和氢进行详细的分析 交换现象以量化这些系统中的内部运动。