Nonhemagglutinating complement-fixing V antigen of parainfluenza 1 virus (HVJ): II. The properties of nonhemagglutinating V antigen

Abstract

The properties of nonhemagglutinating complement-fixing V (NHAV) antigen produced in the allantoic cavity of chick embryos infected with HVJ in its early allantoic passage were studied. NHAV antigen appearing in allantoic fluids (fl.NHAV antigen) consisted of the particles showing a sedimentation rate similar to that of hemagglutinin (HA) particles obtained from infected allantoic fluids. After treatment with ether, small HA (sHA), S antigen, and small NHAV (sNHAV) antigen were released from the particles of fl.NHAV antigen. The ratio of the amount of chicken HA released by ether treatment of fl.NHAV antigen to the V antigen titers of the original preparations was two- to fourfold lower than the chicken HA:V ratio of the HA particles. Correlation of the amount of S antigen released by ether from fl.NHAV antigen to the V antigen titers of the original preparations was comparable with that found with the HA particles. The sNHAV antigen is the subunit from which sHA and S antigen were no longer released by further treatment with ether. The amount of sNHAV antigen in the ether-disintegrated fl.NHAV antigen was nearly equal to that of the V antigen associated with sHA. NHAV antigen obtained from infected chorioallantoic membranes (mem.NHAV antigen) was quite different in its properties from fl.NHAV antigen, but resembled sNHAV subunit. Mem.NHAV antigen showed a much lower sedimentation rate than that of fl.NHAV antigen, and on its exposure to ether no release of HA and S antigen was detectable.