Isolation and characterization of two distinct types of HVJ (Sendai virus) spikes

Abstract

Solubilization of the envelope of HVJ (Sendai virus) with alkali-Tween 20 and subsequent fractionation by sucrose density electrofocusing in the presence of Tween 20 resulted in the separation of two biologically distinct glycoproteins: one protein banded at pH 4.9 without hemagglutinin and neuraminidase activities (HANA −) and the other at pH 6.5 with both hemagglutinin and neuraminidase activities (HANA +). Morphologically, both fractions consisted of dumbbell-shaped spikes, with HANA − spikes exhibiting more definite contour in or shape of knob and shaft than HANA + spikes. Serologically, HANA − and HANA + spikes were distinct from each other in micro-Ouchterlony test. Moreover, SDS-polyacrylamide gel electrophoresis revealed that HANA − spikes were composed of two species of glycoproteins, VP4, (MW, 51,000) and SGP (MW, 15,000), while HANA + spikes contained single glycoprotein, VP2 (MW, 67,000). Radioactivity of HANA − spike fraction did not adsorb onto chicken erythrocyte ghosts, whereas radioactivity, neuraminidase, and hemagglutinin activity of HANA + spike fraction adsorbed onto the ghosts. No hemolytic activity was detected in either HANA − or HANA + spike fractions.