Time-Resolved Tryptophan Fluorescence as a Tool for Studying Picosecond Protein Dynamics

蛋白质是动态分子，在执行其特定功能时经常发生构象变化，如酶反应、配体结合或离子泵送。了解蛋白质动力学提供了对各种重要蛋白质系统功能的见解。本项目的主要目标是建立荧光数据得到的实验松弛曲线与MD模拟结果之间的定量对应关系。另一个目标是获得关于几种蛋白质的更详细的信息，这些蛋白质的实验松弛曲线已经被测量过，并且适合于获得关于动态节段运动与功能关系的信息。这些包括来自大肠杆菌的磷酸载体蛋白IIAGlc的几个单色氨酸突变体，链球菌蛋白G （GB1）的B1结构域及其5FTrp变体，来自流感a- a病毒的M2质子通道，果蝇缺口受体的ANK和RAM结构域的四个单色氨酸突变体，以及两个含单色氨酸突变体的HIV蛋白酶。更广泛的影响包括对年轻科学家进行荧光动力学测量基础知识的教育。作为该项目的一部分而开发的计算机程序及其源代码将提供给广泛的科学界。PI培训了来自阿拉巴马州亨茨维尔奥克伍德学院（Oakwood College）的实习生，这是一所以黑人为主的大学，他们参与了这项研究。这项研究将通过促进教学、学习、培训和扩大代表性不足群体的参与，产生更广泛的影响。本项目由分子与细胞生物科学部的分子生物物理学和化学部的实验物理化学项目共同支持。

Proteins are dynamic molecules that often undergo conformational changes while performing their specific functions, such as an enzyme reaction, ligand binding, or ion pumping. Understanding protein dynamics provides insights into the functions of a variety of important protein systems. The main goal of this project is to establish quantitative correspondence between the experimental relaxation curves obtained from fluorescence data and the results of MD simulations. An additional goal is to obtain more detailed information about several proteins with which the experimental relaxation curves have already been measured and which are suitable for obtaining information about the relation of dynamic segmental motions to function. These include several single-Trp mutants of the phospho-carrier protein IIAGlc from Escherichia coli, the B1 domain of Streptococcal protein G (GB1) and its 5FTrp variant, the M2 proton channel from influenza-A virus, four single Trp containing mutant forms of the ANK and RAM domains of the drosophila notch receptor, and two single Trp containing mutant forms of HIV protease. The broader impacts include education of young scientists in the fundamentals of fluorescence dynamics measurements. Computer programs developed as part of this project and their source code will be made available to the broad scientific community. The PI trains student interns from Oakwood College in Huntsville Alabama, a predominantly black college, who participate in this research. The research will have a broader impact by promoting teaching, learning, training, and broadening the participation of under-represented groups. This project is being jointly supported by Molecular Biophysics in the Division of Molecular and Cellular Biosciences and the Experimental Physical Chemistry Program in the Chemistry Division.