Exploring protein solution structure: Second moments of fluorescent spectra report heterogeneity of tryptophan rotamers.

ABSTRACT: Trp fluorescent spectra appear as a log-normal function but are usually analyzed with λmax, full width at half maximum, and the first moment of incomplete spectra. Log-normal analyses have successfully separated fluorescence contributions from some multi-Trp proteins but deviations were observed in single Trp proteins. The possibility that disparate rotamer environments might account for these deviations was explored by moment spectral analysis of single Trp mutants spanning the sequence of tear lipocalin as a model. The analysis required full width Trp spectra. Composite spectra were constructed using log-normal analysis to derive the inaccessible blue edge, and the experimentally obtained spectra for the remainder. First moments of the composite spectra reflected the site-resolved second

SUBMITTER: Gasymov OK 

PROVIDER: S-EPMC4550534 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature