DESIGN AND EVALUATION OF A TIGHTLY BINDING FLUORESCENT LIGAND FOR INFLUENZA-A HEMAGGLUTININ

Attachment of influenza virus to susceptible cells is mediated by the viral protein hemagglutinin, which recognizes cell-membrane-bound glycoconjugates that terminate in alpha-sialosides. We have synthesized a fluorescent alpha-sialoside that has the highest affinity of any reported monovalent ligand for hemagglutinin, and it is not a substrate for the viral neuraminidase. This alpha-sialoside provides a convenient fluorescence competition assay for the binding of other ligands. Since each of the currently used binding assays has significant disadvantages, such a simple assay is of great importance for the study of potential inhibitors of viral attachment.