Studying the Interactions between Monosaccharide / Polysaccharide with Tryptophan Using Fluorescence Spectroscopy

Abstract

Fluorescence spectroscopy has become a pivotal tool in biochemical research by virtue of its robustness and high sensitivity. Intrinsic protein fluorescence, that originates mainly from the aromatic amino acid tryptophan, have been extensively explored to study protein dynamics and conformational changes. Tryptophan has the strongest fluorescence quantum yield of all the amino acids found in proteins and its fluorescence is highly dependent on the surrounding environment. Therefore, properties including absorption and fluorescence maxima (l max), florescence intensity, and quantum yield have been used to probe conformational changes in a protein due to the change in external environment. Intrinsic tryptophan fluorescence spectroscopy is routinely used to study the impact of common metabolites and metal ions on proteins conformations and functions. However, the impact of some of these metabolites, specifically monosaccharides and polysaccharides, on free tryptophan has remained unknown. In our lab, we are performing a thorough investigation of the impact of monosaccharides and polysaccharides on free tryptophan using fluorescence spectroscopy. The preliminary results of our study are presented here.