MEMBRANE PROTEINS--STRUCTURE, DYNAMICS AND STABILITY

膜蛋白——结构、动力学和稳定性

• 批准号: 6045190
• 负责人: CRAIG C SCHENCK
• 金额: $ 46.04万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6045190
• 关键词: Escherichia coli; bacterial proteins; intermolecular interaction; membrane proteins; nuclear magnetic resonance spectroscopy; protein folding; protein structure function; solid state; solutions; thermodynamics

Membrane protein structures are vastly underrepresented in structure databases in relation to their importance and prevalence in living organisms. The investigators propose to develop and integrate novel liquids and solids NMR methods and biochemical methods (disulfide crosslinking and thermodynamic measurements) to determine the structure of a large membrane protein for the first time. LH1 protein, a 200 kD hetero-oligomeric membrane protein from photoheterotrophic eubacteria, undergoes multiple reversible unfolding (dissociation) and folding (association) reactions, and is well-suited for high-resolution structure determination by liquids and solids NMR. The proposed studies represent an important methodological proof-of-concept that will encourage structural investigations on other membrane proteins with direct medical relevance. The goal of the liquids NMR experiments is to determine the structures of LH1 subcomplexes and to ascertain the degree to which the individual solution structures can be used to build up structures of the intact complex. The solids NMR experiments will be used to determine structures of subcomplexes and intact complexes in a variety of solvent conditions, with the goal of determining NMR signatures for assessing membrane protein folding (association). Liquids and solids NMR dynamics will be ascertained for side- chain and backbone motions on a variety of timescales and they will be compared for LH1 and its subcomplexes. The dynamics will be related to the disulfide crosslinking kinetics, and to the thermodynamics of association. The overall goal is to understand the relationship between structure, conformational dynamics, function and thermodynamic stability for membrane proteins.

在结构数据库中，膜蛋白结构与生物中的重要性和流行有关。 研究人员建议开发和整合新型液体和固体NMR方法和生化方法（二硫键交联和热力学测量值），以首次确定大型膜蛋白的结构。 LH1蛋白是来自光旋转性杆菌的200 kD异质膜膜蛋白，经历了多种可逆的展开（分离）和折叠（关联）反应，非常适合液体和固体NMR的高分辨率结构测定。 拟议的研究代表了一种重要的方法论证明，该概念概念将鼓励对具有直接医学相关性的其他膜蛋白进行结构研究。液体NMR实验的目标是确定LH1亚复合物的结构，并确定可以使用单个溶液结构来建立完整复合物的结构的程度。 固体NMR实验将用于确定各种溶剂条件下亚复合物和完整复合物的结构，目的是确定用于评估膜蛋白折叠（关联）的NMR签名。液体和固体NMR动力学将用于各种时间尺度上的侧链和骨干运动，并将其与LH1及其子复合物进行比较。 该动力学将与二硫键交联动力学以及关联的热力学有关。总体目标是了解膜蛋白的结构，构象动力学，功能和热力学稳定性之间的关系。