PROTEIN DYNAMICS IN BACTERIORHODOPSIN & RHODOPSIN

这些实验的目的是检测和测量内部运动， 细菌视紫红质随时间的分辨率为1 ps至40 ps（初始） 制度从1 ps到1 ms，作为探针的蛋白质动力学和蛋白质- 发色团相互作用 本实验拟研究：1） 细菌视紫红质发色团整体运动的幅度和速率 在其光适应状态和中间体J、K和L中; 2） 发色团的应变构象的松弛; 3）活化 发色团运动的障碍; 4）温度和溶剂依赖性 结合位点几何形状; 5）溶剂粘度依赖性， 发色团弛豫; 6）质子配位到邻近的酪氨酸 发色团;和7）发色团演化的活化体积。 研究低温动力学和室温 皮秒构象演化也提出了视紫红质。 我们的方法的独特之处是：1）时间制度的可访问性 在单个仪器上从1 ps到1 ms; 2）检测内部运动 通过不受激发态限制的各向异性衰减的探测 寿命; 3）详细测量特定的 振动特征; 4）温度和压力的精确研究 弛豫速率的依赖性。 提出的方法是使用天然发色团作为蛋白质的探针 动力学 几种皮秒激光技术解决了这个问题 能够生成关于结构的具体和详细的信息， 动力学

The aim of these experiments is to detect and measure internal motion in bacteriorhodopsin with 1 ps to 40 ps (initially) resolution over time regimes from 1 ps to 1 ms, as a probe of protein dynamics and protein- chromophore interaction. Experiments are proposed to study: 1) the amplitude and rate of overall motion of the bacteriorhodopsin chromophore in its light-adapted state and in intermediates J, K, and L; 2) the relaxation of strained conformations of the chromophore; 3) activation barriers to chromophore motion; 4) the temperature and solvent dependence of the binding site geometry; 5) the solvent viscosity dependence of chromophore relaxation; 6) proton coordination to a tyrosinate adjacent to the chromophore; and 7) activation volumes for chromophore evolution. Experiments to study low-temperature dynamics and room-temperature picosecond conformational evolution are also proposed for rhodopsin. Unique aspects of our approach are: 1) the accessibility of time regimes from 1 ps to 1 ms on a single instrument; 2) detection of internal motion by a probe of anisotropy decay that is not limited by the excited-state lifetime; 3) detailed measurement of relaxation rates of specific vibrational features; 4) accurate studies of the temperature and pressure dependence of relaxation rates. The approach proposed is to use a natural chromophore as a probe of protein dynamics. This problem is attacked by several picosecond laser techniques capable of generating specific and detailed information about structure and dynamics.