NMR STUDIES OF BIOLOGICAL MEMBRANES

能量传递和信号传导是所有细胞的重要过程 生物系统和自然界经常利用视网膜色素 （Rhodopsins）在这些能力。 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 引发了生物反应 一个明显的重要特征 这些膜蛋白是它们的波长辨别力。 换句 在原始细菌中发现的视紫红质，入射光被转化为 电化学能 这些膜蛋白的核心特征是 一种光循环，其中离子的释放和吸收发生在 膜。 由于其相对的可访问性和稳定性， 盐生盐杆菌（Halobacterium halobium）的细菌视紫红质（bacteriorhodopsin，bR）是一种理想的系统 用于研究波长调节和离子传输。 固态nmr 和FTIR差谱作为非微扰探针。 将在特定地点对样品进行同位素富集，以增强核磁共振 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 研究标记的样品在静息状态和早期 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 和理论计算。 除了阐明这些特性之外， 希望这项研究的结果 将有助于提供一个概念框架， 化学驱动、能量和信号转导膜蛋白。 关于这些蛋白质的信息对我们的研究至关重要。 了解正常和病理细胞的调节和功能。

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.