The Molecular Recognition of Saccharides and Glycoprotein-Inspired Materials

Studies of biological molecular recognition events have primarily focused on high affinity recognition processes. Our research program focuses instead on a class of apparent weak interactions that play significant roles in biology, those that occur when proteins bind to extracellular carbohydrates. Such protein-carbohydrate interactions are essential participants in many physiological cell-cell recognition processes, including fertilization, bacterial and viral pathogenesis, and the inflammatory response (Dwek 1996; Feizi 1993; Gabius 1997; Lis and Sharon 1998; Varki 1993). Consistent with their roles in fundamental biological processes, saccharides display many functional groups on diverse scaffolds. Indeed, oligosaccharides can display a diversity of structure that far exceeds that of proteins and nucleic acids (Laine 1994). Even with this potential for conveying structural information, monovalent protein-carbohydrate interactions often occur not only with low affinity (i.e., Ka ≈ 103–4 M-1) (Elgavish and Shaanan 1997; Glaudemans 1991; Lee and Lee 1995; Lis and Sharon 1998; Quiocho et al. 1989; Weis and Drickamer 1996) but also with broad specificity. We have begun to address key questions in this area: How do low affinity protein — saccharide interactions mediate specific molecular recognition events? What advantages do these interactions confer in a biological setting?