Isolation and studies of myxovirus glycoproteins.

The isolation of ortho- and paramyxovirus glycoproteins using a new nonionic detergent (MESK) is reported. MESK was shown to solubilize most of the viral envelope glycoproteins without decreasing their biologic activity. Solubilized glycoproteins are not contaminated by any internal viral proteins or by appreciable quantities of viral envelope lipids. The removal of MESK by dialysis resulted in the formation of glycoprotein micelles. The immunogenic activity of isolated glycoproteins was compared to that of virus particles. Immunization with isolated glycoproteins was shown to protect mice against a lethal influenza infection. Virions were treated with MESK in the presence of exogenous egg phosphatidylcholine, detergent was removed by dialysis and the glycoprotein was reconstituted in the vesicles. This reconstitution was accompanied by restoration of the haemolytic activity of Sendai virus proteins up to that of native virus particles. The level of activity, also the morphology and buoyant density of the vesicle were dependent on the protein/lipid ratio. MESK proved to be of value for the selective solubilization of the surface glycoproteins of animal enveloped viruses and their reconstitution in liposomes.