Using 7-azaindole to probe condensed phase dynamics

In order to study experimentally the ultrafast (<1 picosecond to several hundreds of picoseconds) molecular dynamics of protein-protein interactions, an optical probe is required. Tryptophan has been the most widely used intrinsic optical probe of protein structure and dynamics. There are, however, two major problems attendant to the use of tryptophan, especially in fluorescence measurements. First, since tryptophan is a naturally-occurring amino acid there are often several tryptophans in a protein molecule whose emission must be distinguished. Second, the fluorescence decay of tryptophan itself in aqueous solution is nonexponential. We have consequently investigated alternatives to tryptophan. Our work has led us to the amino acid analog, 7-azatryptophan, and its chromophoric moiety, 7-azaindole.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.