HIGH PRESSURE NMR STUDIES OF PROTEINS AND MEMBRANES

蛋白质和膜的高压核磁共振研究

• 批准号: 3301008
• 负责人: JIRI JONAS
• 金额: $ 16.1万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3301008
• 关键词: conformation; fluid; homopeptide; liposomes; lysozyme; mechanical pressure; membrane activity; membrane lipids; molecular dynamics; myoglobin; nuclear magnetic resonance spectroscopy; phase change; phospholipids; protein folding; protein structure; temperature; thermodynamics

The long-term objective of the proposed research is the elucidation of the effects of pressure on the dynamics and structure of proteins and biological membranes. Pressure is a fundamental thermodynamic variable that provides information on processes that involve changes in volume, including the folding and unfolding of proteins, lipid phase changes in membranes, and the modulation of the fluidity and interfacial properties of membranes. The proposed work focuses on the effects of pressure on the dynamics, phase state, and conformation of several model systems: homopolypeptides (poly-L-lysine, poly-L-glutamic acid, and poly-N -(3- hydroxypropyl)-L-glutamine), hen egg-white lysozyme, sperm whale myoglobin, and various pure phospholipids in the form of sonicated vesicles or multilamellar dispersions. A variety of advanced high resolution NMR methods, using H, H, P nuclei, will be employed together with unique high-pressure NMR probes, in the range from 1 bar to 1O kbar and from 0 to, 100 degree C. In the proteins and the homopolypeptides, selected 1H and 13C resonances will be used to study the dynamics in various regions of the macromolecules, and to examine the thermodynamics and kinetics of the folding-unfolding transitions. The dynamics of phospholipid molecules in liposomes will be studied by 13C NMR: the order and con-formation of the acyl chains and the head groups will be investigated by 13C-NMR, using deuterated lipids, and by H-2D NMR techniques: and phase changes will be examined by 31P and H NMR methods. In addition, slow motions and the lateral diffusion of phospholipids in liposomes will be investigated by rotating frame NMR relaxation techniques.

拟议研究的长期目标是阐明 压力对动力学和结构的影响 蛋白质和生物膜。 压力是基本的 热力学变量提供有关过程的信息 涉及体积的变化，包括折叠和展开 蛋白质，膜的脂质相变，调制 膜的流动性和界面特性。 提议 工作重点是压力对动力学的影响，相位 状态和几种模型系统的构象：均质素肽 （聚-L-赖氨酸，聚-L-谷氨酸和聚-N-（3-） 羟丙基）-l-谷氨酰胺），母鸡卵溶菌酶，抹香鲸 肌红蛋白和各种纯磷脂的超声形式 囊泡或多层分散。 各种高级高 使用H，H，P核的分辨率NMR方法将采用 以及独特的高压NMR探针，范围从 1杆至1o kbar，从0到100度C。在蛋白质中， 均质素肽，选定的1H和13C共振将被使用 研究大分子的各个区域的动力学， 检查折叠的热力学和动力学 过渡。 脂质体中磷脂分子的动力学 将通过13C NMR研究： 酰基链和头部组将由13C-NMR研究， 使用氘代脂质，以及通过H-2D NMR技术：和相位 更改将通过31p和H NMR方法检查。 此外， 缓慢的运动和磷脂中的横向扩散 脂质体将通过旋转框架NMR松弛研究 技术。