Fluorescence determination of tryptophan side-chain accessibility and dynamics in triple-helical collagen-like peptides.

ABSTRACT: We report tryptophan fluorescence measurements of emission intensity, iodide quenching, and anisotropy that describe the environment and dynamics at X and Y sites in stable collagen-like peptides of sequence (Gly-X-Y)(n). About 90% of tryptophans at both sites have similar solvent exposed fluorescence properties and a lifetime of 8.5-9 ns. Analysis of anisotropy decays using an associative model indicates that these long lifetime populations undergo rapid depolarizing motion with a 0.5 ns correlation time; however, the extent of fast motion at the Y site is considerably less than the essentially unrestricted motion at the X site. About 10% of tryptophans at both sites have a shorter ( approximately 3 ns) lifetime indicating proximity to a protein quenching group; these minor populations ar

SUBMITTER: Simon-Lukasik KV 

PROVIDER: S-EPMC1302630 | biostudies-literature | 2003 Jan

REPOSITORIES: biostudies-literature