Comparison of neuraminidases of paramyxoviruses with immunologically dissimilar hemagglutinins

Abstract

The neuraminidase activities of several representatives of the paramyxovirus group were compared. Newcastle disease virus, parainfluenza type I (Sendai) virus, mumps virus, and paramyxovirus Yucaipa, were found to have similar substrate affinities under optimal conditions. The neuraminidase activities of these paramyxoviruses were not stimulated by bivalent cations nor were they inhibited by N-acetyl-neuraminic acid, in contrast to the behavior of the influenza virus activity. The enzymatic activities of these viruses as a function of pH were distinct with one exception: the profiles obtained for a Newcastle disease virus strain and for Sendai virus were partially superimposable. Similarly, the bound hemagglutinins and neuraminidases of each virus studied were shown to be immunologically distinct with this exception: a serological relationship was noted between the neuraminidases of Sendai virus and of Newcastle disease virus. Active hemagglutinin and neuraminidase subviral particles were released from Sendai virus and from Newcastle disease virus by a nonionic detergent treatment, and these particles were separated by chromatography on agarose gel beads. The kinetic properties of the neuraminidases were not altered significantly by this procedure. The enzymes prepared from Sendai virus and from two strains of Newcastle disease virus were found to be serologically related.