Studies of the carbohydrate binding specificity of Concanavalin A using nuclear magnetic resonance spectroscopy

The jack bean lectin Concanavalin A (Con A) is widely used as a biological tool to investigate the membrane properties of both normal and transformed cells. Its ability to bind to cell membranes and selectively agglutinate transformed cells is related to its saccharide binding specificity. Using a variety of nuclear magnetic resonance (NMR) techniques, we have investigated the molecular properties of the lectin which are associated with its carbohydrate binding activity. Our studies have provided information on the location and size of the carbohydrate binding site in the protein, the role of metal ion binding and activation of the lectin, the kinetics and thermodynamics of monosaccharide binding, and the relative modes of binding of mono- and oligosaccharides to Con A. Recently, using NMR techniques, we have investigated the interaction of the protein with complex and high mannose type glycopeptides, which are putative 'Con A receptors' on the surface of cells, as well as with synthetic oligosaccharide analogs. These studies have led to new insights regarding the saccharide binding specificity of the lectin.