Lehnert U, Réat V, Weik M, Zaccaï G, Pfister C
Institut de Biologie Structurale, 38027 Grenoble Cedex 1, France.
Biophys J. 1998 Oct;75(4):1945-52. doi: 10.1016/S0006-3495(98)77635-0.
Bacteriorhodopsin (BR) is a transmembrane protein in the purple membrane (PM) of Halobacterium salinarum. Its function as a light-driven proton pump is associated with a cycle of photointermediates which is strongly hydration-dependent. Using energy-resolved neutron scattering, we analyzed the thermal motions (in the nanosecond-to-picosecond time range) in PM at different hydration levels. Two main populations of motions were found that responded differently to water binding. Striking correlations appeared between these "fast" motions and the "slower" kinetic constants (in the millisecond time range) of relaxations and conformational changes occurring during the photocycle.
细菌视紫红质（BR）是嗜盐菌紫膜（PM）中的一种跨膜蛋白。其作为光驱动质子泵的功能与光中间体循环相关，该循环强烈依赖水合作用。利用能量分辨中子散射，我们分析了不同水合水平下紫膜中（纳秒到皮秒时间范围内）的热运动。发现了两种主要的运动群体，它们对水结合的反应不同。在这些“快速”运动与光循环过程中发生的弛豫和构象变化的“较慢”动力学常数（毫秒时间范围内）之间出现了显著的相关性。
