A SURFACE-PLASMON RESONANCE ASSAY FOR THE BINDING OF INFLUENZA-VIRUS HEMAGGLUTININ TO ITS SIALIC-ACID RECEPTOR

We have developed a sensitive microscale binding assay to study the in teraction between influenza hemagglutinin and its cell surface recepto r sialic acid using real-time surface plasmon resonance. The glycoprot ein fetuin was bound to a carboxymethylated-Dextran sensor surface usi ng N-hydroxysuccinimide and N-ethyl-N'-(dimethylaminopropyl) carbodiim ide. Low-pH-induced BHA rosettes bind specifically to the fetuin-deriv itized sensor surface, but not to an a sia lofetuin-derivitized sensor surface. Binding can be inhibited by preincubation of BHA rosettes wi th millimolar concentrations of inhibitors of the influenza hemaggluti nin-sialic acid interaction. The association rate, dissociation rate, and dissociation constant for the multivalent interaction between BHA rosettes and the fetuin-derivitized sensor surface were also measured, allowing us to quantitate the tight binding achieved through the mult ivalent interaction between BHA rosettes and the fetuin-derivitized se nsor surface. (C) 1996 Academic Press, Inc.