NMR STUDIES OF BIOLOGICAL MEMBRANES

生物膜的核磁共振研究

• 批准号: 3291314
• 负责人: JUDITH HERZFELD
• 金额: $ 19.91万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-30 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3291314
• 关键词: Halobacteriaceae; bacteriorhodopsins; biological signal transduction; chromophore; conformation; electron density; electronic spectra; infrared spectrometry; ion transport; ionophores; membrane model; membrane proteins; molecular energy level; nuclear magnetic resonance spectroscopy; photochemistry; physical model; protein sequence; protein structure function; quantum chemistry; radiotracer

Energy transduction and signal transduction are important processes in all biological systems, and nature often makes use of retinal pigments (rhodopsins) in these capacities. In the vertebrate visual pigments, and in the phototactic pigments of unicellular organisms, incident light precipitates a biological response. An obviously important feature of these membrane proteins is their wavelength discrimination. In other rhodopsins, found in primitive bacteria, incident light is converted into electrochemical energy. The central feature of these membrane proteins is a photocycle in which ion discharge and uptake occur on opposite sides of the membrane. Because of its relatively accessibility and stability, bacteriorhodopsin (bR), from the Halobacterium halobium, is an ideal system for studying both wavelength regulation and ion transport. Solid state NMR and FTIR difference spectroscopy are to used as non-perturbative probes. Samples will be isotopically enriched at specific sites to enhance NMR signals of interest, suppress interfering NMR signals, and induce informative shifts in vibrational frequencies. FTIR and NMR will be used to study the labeled samples in the resting state and in the early photocycle intermediates. NMR will also be used to study wavelength perturbed states, to follow ion movement in the protein, and to measure changes in the distances between groups and their relative orientations. The interpretation of the spectra will be based on model compound studies and on theoretical calculations. In addition to elucidating the properties of this light driven system, it is hoped that the results of this study will help to provide a conceptual frame work for understanding other, chemically driven, energy and signal transducing membrane proteins. Information about such proteins is ultimately important to our understanding of normal and pathological cell regulation and function.

能量转导和信号转导是其中重要的两个过程