Synthesis of Oligomeric Mannosides and Their Structure-Binding Relationship with Concanavalin A

Abstract

Small glycodendrimers with a-mannosyl ligands were synthesized by using copper-catalyzed azide-alkyne coupling chemistry and some of these molecules were used as multivalent ligands to study the induction of concanavalin A (Con A) precipitation. The results showed that the monovalent mannose ligand could induce the precipitation of Con A. This unexpected finding initiated a series of studies to characterize the molecular basis of the ligand-lectin interaction. The atypical precipitation is found to be specific to the mannose, fluorescein moiety (FITC), and Con A. Apparently the mannose ligand binds to Con A through hydrogen-bonding interactions, whereas the binding of FITC is mediated by hydrophobic forces.