Synthesis of oligomeric mannosides and their structure-binding relationship with concanavalin A

Small glycodendrimers with α-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. Being precipitate: A series of glycodendrimers with α-mannosyl ligands were prepared and used to explore the precipitation of concanavalin A (Con A). Surprisingly, the monovalent mannose ligand induced Con A precipitation, which led to an investigation of the molecular basis of the ligand-lectin interaction (see figure).