Fluorescence-based characterization of non-fluorescent transient states of tryptophan - prospects for protein conformation and interaction studies.

ABSTRACT: Tryptophan fluorescence is extensively used for label-free protein characterization. Here, we show that by analyzing how the average tryptophan fluorescence intensity varies with excitation modulation, kinetics of tryptophan dark transient states can be determined in a simple, robust and reliable manner. Thereby, highly environment-, protein conformation- and interaction-sensitive information can be recorded, inaccessible via traditional protein fluorescence readouts. For verification, tryptophan transient state kinetics were determined under different environmental conditions, and compared to literature data. Conformational changes in a spider silk protein were monitored via the triplet state kinetics of its tryptophan residues, reflecting their exposure to an air-saturated aqueous soluti

SUBMITTER: Hevekerl H 

PROVIDER: S-EPMC5066179 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature