BIOCHEMICAL AND BIOPHYSICAL STUDIES ON NUCLEOCAPSID AND ON RNA OF RABIES VIRUS

Nucleocapsids containing the viral ribonucleic acid (RNA) were isolated from deoxycholate (DOC)-disrupted rabies virions by rate zonal centrifugation in sucrose gradient followed by equilibrium centrifugation in CsCl gradient. The sedimentation coefficient of the nucleocapsid is approximately 200 S and its buoyant density in CsCl is 1.32. The nucleocapsid is composed of 96% protein and 4% RNA. It is a single-stranded, right-handed helix. The helix is about 1.0 μ long, 100 Å in diameter, and has a periodicity of 75 Å. The helical structure of the nucleocapsid is extremely labile. The uncoiled strand of the helix is about 4.2 μ long, and its width varies from 20 to 65 Å depending on the angle of viewing. The nucleocapsid exhibits complement fixing, but not hemagglutinating (HA), activity. It is noninfectious. The viral RNA isolated from virions or nucleocapsids is single-stranded and has a sedimentation coefficient of 45 S. The envelope of the virion exhibiting HA activity is disintegrated by DOC into slowly sedimenting subunits. They possess hemagglutination-inhibition activity, but not HA activity. © 1969.