In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Prof. Callis of Montana State University will study the lowest-lying electronic states of indoles using experimental and theoretical methods. The experiments will range from gas-phase to condensed-phase spectroscopic studies, and the calculations will use a semi-empirical theory which incorporates solute-solvent interactions. These studies of indoles are of interest because indoles constitute the chromophore of the amino acid tryptophan, and an analysis of their spectra can help elucidate the effect of the solvent and protein environment on the electronic state energies and dynamics of the chromophores. %%% In recent years many studies have sought to understand the fundamental functions of the molecular species involved in the chemistry of living organisms. The current work will attempt to understand how the photochemically active constituent of the amino acid tryptophan might contribute to the functioning of proteins and enzymes which contain it. Such studies could have far-reaching effects. For example, recent work suggests that tryptophans may play an important role in modulating and directing large scale motions in proteins such as the enzyme lysozyme.
