NMR STUDIES OF BIOLOGICAL MEMBRANES

能量转导和信号转导是所有过程中的重要过程 生物系统，自然界经常利用视网膜色素 (视紫红质)在这些能力。在脊椎动物的视觉色素中，以及 在单细胞生物的趋光性色素中，入射光 沉淀一种生物反应。的一个明显的重要特征 这些膜蛋白是它们的波长分辨。在其他 在原始细菌中发现的视紫红质，入射光被转化为 电化学能。这些膜蛋白的中心特征是 一种光循环，其中离子的释放和吸收发生在 膜。由于其相对易达性和稳定性， 细菌视紫红质(BR)是从盐生盐杆菌中分离出来的一种理想的系统 用于研究波长调节和离子传输。固体核磁共振 和FTIR差示光谱作为非微扰探针。 样品将在特定位置进行同位素浓缩，以增强核磁共振 感兴趣的信号，抑制干扰核磁共振信号，并诱导 振动频率的信息性变化。将使用傅里叶变换红外光谱和核磁共振 对静息状态和早期标记样品的研究 光循环中间体。核磁共振也将被用来研究波长 微扰状态，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。 对光谱的解释将以模型化合物研究为基础 以及理论上的计算。除了阐明它们的性质之外 对于这种光驱动系统，希望这项研究的结果 将有助于提供一个概念性的框架来理解其他， 化学驱动、能量和信号转导的膜蛋白。 关于这些蛋白质的信息最终对我们的 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.