Influence of the isolation procedure on the structure, neuraminidase and heamagglutinating activities of Sendai virus envelope glycoproteins.

The influence of the isolation procedure of Sendai virus glycoproteins from the virus surface on their neuraminidase and haemagglutinating activities, as well as on some structural properties was studied. These glycoproteins exhibited lower specific neuraminidase and haemagglutinating activities than those of intact virus. Neuraminidase activity was expressed when the glycoproteins were constituted in forms with molecular weights of about 70,000 (monomer), 160,000 (dimer), 300,000 (tetramer) or 600,000 (octamer), whereas haemagglutinating activity was only found for the glycoproteins aggregated in a high mol. wt. (approximately 10(6) daltons) form. The isolated glycoproteins contained two subunits revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and three distinct antigenic components revealed by rocket immunoelectrophoresis. Different treatments of the glycoproteins after their isolation altered their structure. Consequently either neuraminidase and haemagglutinating activities were signicantly reduced, or one of these activities was not expressed.