MEMBRANE-FUSION OF INFLUENZA-VIRUS WITH PHOSPHATIDYLCHOLINE LIPOSOMES CONTAINING VIRAL RECEPTORS

pH-dependent membrane fusion of influenza virus with liposomes made of phosphatidylcholine was studied by the spin-labelling method. Efficiency of viral fusion with liposomes composed of dimyristoyl phosphatidylcholine or dipalmitoyl phosphatidylcholine was considerably lower compared to dioleoyl phosphatidyl choline or egg yolk phosphatidylcholine, suggesting importance of unsaturation of acyl chains of lipid bilayers. Reconstitution of specific viral receptors such as Glycophorin or sialylparagloboside strongly enhanced fusion with liposomes composed of dimyristoyl phosphatidylcholine. A direct comparison between the activities of the receptors showed that Glycophorin was about 50 times more effective than sialylparagloboside at the same receptor / phosphatidylcholine molar ratio. © 1992 Academic Press, Inc.