The dead-end elimination method, tryptophan rotamers, and fluorescence lifetimes.

ABSTRACT: The Dead-End Elimination method was used to identify 40 low energy microconformations of 16 tryptophan residues in eight proteins. Single Trp-mutants of these proteins all show a double- or triple-exponential fluorescence decay. For ten of these lifetimes the corresponding rotameric state could be identified by comparing the bimolecular acrylamide quenching constant (k(q)) and the relative solvent exposure of the side chain in that microstate. In the absence of any identifiable quencher, the origin of the lifetime heterogeneity is interpreted in terms of the electron transfer process from the indole C epsilon 3 atom to the carbonyl carbon of the peptide bond. Therefore it is expected that a shorter [C epsilon 3-C[double bond]O] distance leads to a shorter lifetime as observed for these ten

SUBMITTER: Hellings M 

PROVIDER: S-EPMC1303361 | biostudies-literature | 2003 Sep

REPOSITORIES: biostudies-literature