Carbohydrate-functionalized dendrimers to investigate the predictable tunability of multivalent interactions

Multivalent protein-carbohydrate interactions mediate a wide variety of intercellular recognition processes with high selectivity and specificity. Many synthetic multivalent molecules have been designed to mimic and to inhibit these processes. Using carbohydrate functionalized dendrimers, our goal is to devise a system where the binding activity and the degree of protein clustering induced by the glycopolymer can be readily attenuated. In this paper, dendrimers were functionalized with mixtures of mannose, glucose, and galactose. Their association with concanavalin A was studied using precipitation and hemagglutination assays. With less idealized systems where the association was not optimized, mixtures of low- and high-affinity ligands caused smaller than the theoretically determined differences in binding activity, although linear binding trends were observed. When systems were optimized so that high-affinity binding was achieved, then mixing low- and high-affinity ligands on the dendrimer's surface showed a predictable trend for lectin binding.