INFRARED STUDIES OF PROTEIN STRUCTURE AND DYNAMICS

蛋白质结构和动力学的红外研究

• 批准号: 2190839
• 负责人: J Timothy SAGE
• 金额: $ 7.77万
• 依托单位: NORTHEASTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2190839
• 关键词: acidity /alkalinity; active sites; carbon monoxide; chemical binding; chemical chain length; conformation; cytochrome c; electron transport; hemoprotein structure; infrared spectrometry; interferometry; intermolecular interaction; lasers; ligands; myoglobin; oxidation reduction reaction; oxygen; photolysis; protein folding; protein structure function; stereochemistry; structural biology; time resolved data; water solution

We propose to develop and apply techniques, primarily based on Fourier- transform infrared spectroscopy, to investigate protein structure, dynamics, and function at the level of the individual groups. One phase of this project will involve polarized IR studies of oriented single crystals. The binding geometry of small molecules to metalloproteins will be determined and related to protein control of active site function. We will use 1R difference techniques to perform single site pH titrations and deduce conformational changes induced by active site reactions. We will identify changes in protein structural or dynamic properties introduced by crystallization through spectroscopic comparisons with solutions. A second, parallel phase of the project will use sensitive difference techniques to explore IR spectral changes during photoinduced reactions. The use of continuous, impulsive, and modulated laser excitation will allow the study of reversible and irreversible reactions that have a wide range of quantum yields. We will use these techniques to investigate structural alterations associated with protein folding, UV radiation damage, and the coupling of protein conformation to ligand binding and redox reactions at the active site. We will also initiate studies aimed at exploring the connection between hydration and protein function. The long-term objectives of this work have both specific and general aspects. On a specific level, reactions of electrons and oxygen with metalloproteins play essential roles in oxidative phosphorylation. We expect that diatomic molecules will become increasingly important for understanding intracellular processes, with the growing awareness of the diverse biological roles of nitric oxide and carbon monoxide in intracellular communication and regulation. On a more general level, the relative simplicity of the reactions in most of the proteins studied makes them ideal model systems with which-to address questions about how protein conformation controls active site reactivity, and how ligand binding alters protein conformation. Fundamental insights into such generic questions will become increasingly important both in order to understand biological systems at the molecular level and to adapt and redesign biological molecules for medical and technological applications.

我们建议开发和应用技术，主要基于傅立叶 - 转化红外光谱，以研究蛋白质结构， 动态和在各个组级别的功能。一个阶段 该项目将涉及定向单个的极化IR研究 晶体。小分子与金属蛋白的结合几何形状将 确定并与活性位点功能的蛋白质控制有关。我们 将使用1R差异技术执行单个站点pH滴定和 推断由主动部位反应引起的构象变化。 我们将 确定蛋白质结构或动态特性的变化 通过与溶液的光谱比较结晶。一个 其次，该项目的平行阶段将使用敏感差异 在光诱导的反应过程中探索红外光谱变化的技术。 连续，冲动和调节激光激发的使用将 允许研究具有广泛的可逆反应和不可逆反应 量子收率范围。我们将使用这些技术进行调查 与蛋白质折叠，紫外线辐射相关的结构改变 损伤，以及蛋白质构象与配体结合的偶联和 活跃部位的氧化还原反应。我们还将启动针对的研究 探索水合与蛋白质功能之间的联系。 这项工作的长期目标既有特定又有一般的目标 方面。在特定水平上，电子和氧与 金属蛋白在氧化磷酸化中起重要作用。我们 预计双原子分子对 了解细胞内的过程，随着对 一氧化氮和一氧化碳在 细胞内沟通和调节。在更一般的层面上， 在研究的大多数蛋白质中，反应的相对简单性使得 他们是理想的模型系统，哪种方法可以解决有关蛋白质的问题 构象控制主动位点反应性以及配体结合如何 改变蛋白质构象。对这种通用的基本见解 为了理解，问题将变得越来越重要 分子水平的生物系统并适应和重新设计 用于医学和技术应用的生物分子。