A topographic map of the enzyme active center and antigenic sites on the neuraminidase of influenza virus A/Tokyo/3/67 (H2N2)

Abstract

The antigenic structure of an influenza virus neuraminidase was probed with a panel of eight monoclonal antibodies and two different-sized substrates, fetuin and N-acetylneuraminyl lactose. Results of competitive radioimmunoassays between monoclonal antibodies indicated the existence of three overlapping antigenic sites. The effects of the same panel of monoclonal antibodies on the enzyme-catalyzed hydrolysis of sialic acid from fetuin (molecular weight 50,000 daltons) and from N-acetylneuraminyl lactose (molecular weight 600) were also examined. These results indicated that each of the antibodies prevented the approach of fetuin to the enzyme active center, whereas only three inhibited hydr..