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

Johns Hopkins University, Baltimore MD

Investigators

Abstract

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.