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所有重要过程 生物系统和自然通常使用视网膜色素 （Rhodopsins）在这些能力中。 在脊椎动物的视觉色素中，以及 在单细胞生物的照相色素中，入射光 沉淀生物学反应。 明显的重要特征的 这些膜蛋白是其波长歧视。 在其他 在原始细菌中发现的视紫红蛋白，入射光转化为 电化学。 这些膜蛋白的主要特征是 一个光循环，其中离子放电和吸收发生在 膜。 由于其相对可及性和稳定性， 来自卤代杆菌的细菌霍顿（BR）是一个理想的系统 用于研究波长调节和离子传输。 固态NMR FTIR差异光谱法被用作非扰动探针。 样品将在特定位点富集以增强NMR 感兴趣的信号，抑制干扰NMR信号并诱导 振动频率的信息变化。 FTIR和NMR将使用 在静止状态和早期研究标记的样品 光循环中间体。 NMR也将用于研究波长 扰动状态，跟随蛋白质中的离子运动，并测量 组及其相对取向之间的距离变化。 光谱的解释将基于模型复合研究 以及理论计算。 除了阐明特性 在这个轻驱动系统中，希望这项研究的结果 将有助于提供概念上的工作，以理解其他 化学驱动，能量和信号转导的膜蛋白。 关于这种蛋白质的信息最终对我们很重要 了解正常和病理细胞调节和功能。