Use of a Biosensor Based on Surface Plasmon Resonance and Biotinyl Glycans for Analysis of Sugar Binding Specificities of Lectins

抄録

We have developed a new method for analysis of the interaction between lectins and biotin-derivatized oligosaccharides involving a biosensor based on surface plasmon resonance. Complex type asialo-bi-, tri-, and tetra-antennary oligosaccharides were quantitatively converted into their biotin derivatives by incubating them with 6-(D-biotinyl)-aminohexanoyl hydrazide. This method was also applicable to sialyl sugar chains without any removal of sialic acid residues. The reaction mixture could be directly injected onto the streptavidin pre-immobilized surface of a sensor chip without any purification because of its fairly low reagent/carbohydrate molar ratio. The amounts of sugar chains required for interaction analysis by this method were as low as 1 pmol. The binding specificities of Sambucus sieboldiana lectin, Maackia amurensis lectin, Ricinus communis agglutinin-120 (RCA₁₂₀), and concanavalin A could be rapidly determined qualitatively by this method. Furthermore, kinetic analysis of the interaction between RCA₁₂₀, and complex type asialo-bi-, tri-, and tetra-antennary oligosaccharides revealed that both the association rate constant and the dissociation rate constant (k_diss) decreased with increasing numbers of terminal galactosyl residues. Because the tendency observed for kd, ss paralleled the elution order of these oligosaccharides on RCA₁₂₀ immobilized affinity chromatography, k_diss might hold the key to determination of the elution order on affinity chromatography.