Fluorescence polarization as a tool to study lectin-sugar interaction.

The binding of Ricinus communis agglutinin and Abrus agglutinin to 4-methylumbelliferyl β-D-galactopyranoside was studied by equilibrium dialysis, fluorescence quenching and fluorescence polarization. The number of binding sites and the association constant value obtained by fluorescence polarization for both Ricinus communis agglutinin and Abrus agglutinin are in close agreement with those obtained by the other methods. This indicates the potential of ligand-fluorescence polarization measurements in the investigation of lectin-sugar interactions.