NMR STUDIES OF BIOLOGICAL MEMBRANES

生物膜的核磁共振研究

• 批准号: 3291313
• 负责人: JUDITH HERZFELD
• 金额: $ 18.62万
• 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/3291313
• 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生命活动中的重要过程 生物系统和大自然经常利用视网膜色素 （视紫红质）具有这些能力。 在脊椎动物的视觉色素中， 在单细胞生物的趋光色素中，入射光 引发生物反应。 一个明显重要的特征是 这些膜蛋白的区别在于它们的波长。 在其他方面 视紫红质，存在于原始细菌中，入射光被转化为 电化学能。 这些膜蛋白的中心特征是 光循环，其中离子放电和吸收发生在相反的两侧 膜。 由于其相对的可访问性和稳定性， 细菌视紫红质 (bR) 来自盐杆菌，是一个理想的系统 用于研究波长调节和离子传输。 固态核磁共振 和 FTIR 差分光谱用作非微扰探针。 样品将在特定位点进行同位素富集以增强 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。 将使用 FTIR 和 NMR 研究静息状态和早期的标记样本 光循环中间体。 核磁共振也将用于研究波长 扰动状态，跟踪蛋白质中的离子运动，并测量 群体之间的距离及其相对方向的变化。 光谱的解释将基于模型化合物研究 以及理论计算。 除了阐明属性之外 对于这个光驱动系统，希望这项研究的结果 将有助于提供一个概念框架来理解其他， 化学驱动的能量和信号转导膜蛋白。 有关此类蛋白质的信息最终对我们很重要 了解正常和病理细胞的调节和功能。