Picosecond fluorescence dynamics of tryptophan and 5-fluorotryptophan in monellin: slow water-protein relaxation unmasked.

ABSTRACT: Time dependent fluorescence Stokes (emission wavelength) shifts (TDFSS) from tryptophan (Trp) following sub-picosecond excitation are increasingly used to investigate protein dynamics, most recently enabling active research interest into water dynamics near the surface of proteins. Unlike many fluorescence probes, both the efficiency and the wavelength of Trp fluorescence in proteins are highly sensitive to microenvironment, and Stokes shifts can be dominated by the well-known heterogeneous nature of protein structure, leading to what we call pseudo-TDFSS: shifts that arise from differential decay rates of subpopulations. Here we emphasize a novel, general method that obviates pseudo-TDFSS by replacing Trp by 5-fluorotryptophan (5Ftrp), a fluorescent analogue with higher ionization potenti

SUBMITTER: Xu J 

PROVIDER: S-EPMC7477844 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature