Synthesis of Oligomeric Mannosides and Their Structure-Binding Relationship with ConcanavalinA

Small glycodendrimers with [alpha]-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 concanavalinA (ConA) precipitation. The results showed that the monovalent mannose ligand could induce the precipitation of ConA. 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 ConA. Apparently the mannose ligand binds to ConA through hydrogen-bonding interactions, whereas the binding of FITC is mediated by hydrophobic forces. [PUBLICATION ABSTRACT]