Carbohydrate Residue of a Urine Mucoprotein inhibiting Influenza Virus Hæmagglutination

Abstract

THE first step in the propagation of influenza virus is the adsorption of the infective particle on to the receptor substance at the surface of the host cell. Human, guinea pig and fowl erythrocytes, though not susceptible to infection, possess analogous receptors which, by allowing virus particles to form ‘bridges’ between cells, give rise to the hæmagglutination characteristic of influenza viruses¹. A variety of soluble mucoids, by competing with the cellular receptors for the virus, inhibit hæmagglutination². There is much indirect evidence to suggest that the receptors and the soluble mucoids have some basic structure in common, that this common structural feature is predominantly of carbohydrate nature and that the carbohydrate is instrumental in the attachment of the virus to the cell receptors and their mucoid analogues². In fact, the inactivation by living virus of the capacity of a mucoprotein to inhibit hæmagglutination by indicator virus is accompanied by the release of a sugar derivative characterized as an N-substituted fructosamine³.