Dynamic electromagnetophoretic force analysis of a single binding interaction between lectin and mannan polysaccharide on yeast cell surface.

Using the electromagnetophoretic buoyancy for a microparticle in a silica capillary containing an electrolyte solution, the dynamic force dissociation kinetics of the interaction between the mannan polysaccharide on a yeast cell surface and lectins bound to the silica capillary wall have been studied by using the two different modes of the increasing force mode and the constant force mode. Lectins used in the study were concanavalin A (Con A), Hippeastrum hybrid lectin (HHL), Galanthus nivalis lectin (GNL) and Narcissus pseudonarcissus lectin (NPL). The dynamic force measurement by the two different modes gave the spontaneous dissociation rate constant, k(off), of the polysaccharide-lectin binding and the critical increment of bond length at the transition state, Deltax. It was found that the value of k(off) for Con A was the smallest among the lectins studied, due to the strongest binding interaction. It was also confirmed that the magnetophoretic pulling force decreased the transition free energy just like an enzyme.