title: Fusion of Sendai virions or reconstituted Sendai virus envelopes with liposomes or erythrocyte membranes lacking virus receptors.
abstract: Incubation of intact Sendai virions or reconstituted Sendai virus envelopes with phosphatidylcholine/cholesterol liposomes at 37 degrees C results in virus-liposome fusion. Neither the liposome nor the virus content was released from the fusion product, indicating a nonleaky fusion process. Only liposomes possessing virus receptors, namely sialoglycolipids or sialoglycoproteins, became leaky upon interaction with Sendai virions. Fusion between the virus envelopes and phosphatidylcholine/cholesterol liposomes was absolutely dependent upon the presence of intact and active hemagglutinin/neuraminidase and fusion viral envelope glycoproteins. Fusion between Sendai virus envelopes and phosphatidylcholine/cholesterol liposomes lacking virus receptors was evident from the following results. Anti-Sendai virus antibody precipitated radiolabeled liposomes only after they had been incubated with fusogenic Sendai virions. Incubation of N-4-nitrobenzo-2-oxa-1,3-diazole-labeled fusogenic reconstituted Sendai virus particles with phosphatidylcholine/cholesterol liposomes resulted in fluorescence dequenching. Incubation of Tb3+-containing virus envelopes with phosphatidylcholine/cholesterol liposomes loaded with sodium dipicolinate resulted in the formation of the chelation complex Tb3+-dipicolinic acid, as was evident from fluorescence studies. Virus envelopes fuse efficiently also with neuraminidase/Pronase-treated erythrocyte membranes, i.e. virus receptor-depleted erythrocyte membranes, although fusion occurred only under hypotonic conditions.
mesh_terms: D002784:Cholesterol; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006461:Hemolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008081:Liposomes; D009994:Osmolar Concentration; D010222:Parainfluenza Virus 1, Human / Q000378:metabolism*; D010713:Phosphatidylcholines; D011991:Receptors, Virus; D014771:Virion / Q000378:metabolism*
chemical_list: D008081:Liposomes; D010713:Phosphatidylcholines; D011991:Receptors, Virus; D002784:Cholesterol