蛋白质结构动力学的定点标记超快二维红外光谱研究

Effectively monitoring protein structural dynamics in condensed phase is of great importance in both chemistry and biology. Femtosecond two-dimensional infrared (2D IR) spectroscopy is one of the time-resolved vibrational techniques that are extremely sensitive to molecular structures and dynamics. In this proposal, it is proposed, by using the 2D IR method as our primary experimental toolfdfd, by using protein backbone vibrations as intrinsic structural probes, and by site-specific labeling with small-volume, strong-absobing molecular vibrations as extrinsic strucural probes, and also by using infrared difference spectroscopic method, we plan to study two typical photo-sensitive proteins, namely photoactive yellow protein and bacteriorhodopsin, with the latter being known as a membrane protein that pumps protons. We plan to investigate the chemical-bond level equilibrium structural distributions, and ultrafast structural dynamics of the chozen protein systems, on the time scale ranging from picosecond to nearly nanosecond. The results obtained shall be useful in depicting the ultrafast local and regional (and/or global) structural dynamics of the proteins, and in depicting ultrafast photophysical and photochemical processes that are relevent to their biological functions, and in particular in depicting the dynamical structures of protein’s invisible state. The proposed research, once being carried out, shall be helpful in gaining new insight into structure-dynamics-function relationship of functional proteins, and promoting the application of new physical-chemistry techniques in biophysical chemistry, or even in life sciences, eventually establishing an ultrafast 2D IR spectroscopy-based dynamical-structural biology method.

有效地实时跟踪溶液相蛋白质分子的结构动力学在化学和生物领域中均具有重要意义。飞秒二维红外光谱技术是对分子动态结构具有极高灵敏性的时间分辨振动光谱学新方法之一。本项目拟利用飞秒二维红外光谱手段，以蛋白质分子骨架振动为内源结构探针，以定点标记的小体积、强振动分子为外源结构探针，结合红外差谱检测等实验手段，有计划地研究两个典型的光敏蛋白质体系，即黄色光敏蛋白和具有质子泵功能的菌紫质膜蛋白。在化学键水平上研究所选蛋白质分子体系在从皮秒到近纳秒的时间尺度上的动态结构分布及其超快动力学过程，以期描述与其生物活性密切相关的超快光物理和化学过程与现象，特别是揭示功能蛋白质“非可见态”的动态结构。本项目的实施将有助于深入认识蛋白质体系的结构－动力学－功能关系，还将有助于推进物理化学研究新手段在生物物理化学或生命科学中的应用，以期建立一种基于超快二维红外谱学的动态结构生物学方法。

有效地实时跟踪溶液相蛋白质分子的结构动力学在化学和生物领域中均具有重要意义。飞秒二维红外光谱技术是对分子动态结构具有极高灵敏性的时间分辨振动光谱学新方法之一。本项目利用飞秒二维红外光谱手段，以蛋白质分子骨架振动为内源结构探针，以定点标记的小体积、强振动分子为外源结构探针，结合红外差谱检测等实验手段，研究了两个典型的光敏蛋白质体系，即黄色光敏蛋白和具有质子泵功能的菌紫质膜蛋白。在化学键水平上研究所选蛋白质分子体系在从皮秒开始的时间尺度上的动态结构分布及其超快动力学过程，描述了与其生物活性密切相关的超快光物理和化学过程与现象，特别是揭示了功能蛋白质“非可见态”的动态结构。本项目的实施有助于深入认识蛋白质体系的结构－动力学－功能关系，还有助于推进物理化学研究新手段在生物物理化学或生命科学中的应用，为建立一种基于超快二维红外谱学的动态结构生物学方法打下了很好的基础。