Affinity and kinetic studies for the evaluation of lectin-reactive alpha-fetoprotein with a biosensor based on surface plasmon resonance

Affinity and kinetic analyses for the evaluation of lectin-reactive alpha-fetoprotein (AFP) were performed using a biosensor based on surface plasmon resonance (SPR). Human AFP, purified from HCC (hepatocellular carcinoma) patients, was immobilized on the surface of a sensor chip. The interaction of this bound AFP with three lectins, Lens culinaris agglutinin [LCA], concanavalin A [Con-A] and erythroagglutinating phytohemagglutinin [E-PHA]) were monitored in real-time with the change ir. the SPR response. These three lectins produced an increase in the SPR response: indicating that all three bound specifically to the immobilized AFP. The association (k(ass)) and the dissociation (k(diss)) rate constants clearly differed among the three lectin-AFP interactions. These affinity and kinetic analyses of the sugar binding specificities of lectins, employing a biosensor based on SPR, are expected to serve as a new technique with the potential for simple rapid evaluation of lectin-reactive AFP. (C) 1997 Elsevier Science Ireland Ltd.