Abstract: | Materials on comparative ultrastructural analysis of isolated glycoproteins (GP) of influenza, parainfluenza, and Venezuelan equine encephalomyelitis viruses as well as liposomes reconstructed on their basis prepared with the use of MECK, a nonionic detergent, are presented. Original virions, subvirion particles, and isolated GP were characterized by typical morphology and remained intact in highly purified and concentrated suspensions owing to the use of the sparing and effective method of treatment with MECK. After removal of the detergent typical micellar aggregates were shown to form from GP monomers for all three viruses under study. The forming rosettes morphologically and biologically are similar to those isolated from ortho-, paramyxo-, and togaviruses using the Triton X-100 detergent. Stages of liposome formation and interaction with cell membrane were studied electron microscopically. A common feature for liposomes from GP of all the three viruses consisted in the formation of two morphological variants of structural complexes: filaments of various lengths and composition in them of GP and vesicles, the arrays of GP in which were similar or identical to those of viral membrane. Liposomes from Sendai virus GP possessed hemolytic activity, however, their interaction with the cell studied by means of the immunoferritine label occurred not by fusion but apparently as a result of destruction of the cell membrane at the sites of protein F contact with plasmalemma and formation in the latter of defects leading to erythrocyte lysis. |