The polypeptide composition of avian infectious bronchitis virus particles

Abstract

Egg grown avian infectious bronchitis virus (IBV) centrifuged on sucrose density gradients was found to consist of a major virus peak of density 1.17 to 1.18 g/cm(3). Three different IBV strains were examined and no morphological differences were detected between virus particles of different densities or from different strains. The polypeptides of the different density virus particles from the three IBV strains were analysed on polyacrylamide gels. In all cases 7 polypeptides were observed, although there were differences in the proportions of these polypeptides in particles of different densities and those from the different strains. The polypeptides have been called VP1 (molecular weight 130,000), VP2 (105,000), VP3 (97,000), VP4 (81,000), VP5 (74,000), VP6 (51,000) and VP7 (33,000). Additional polypeptides were produced if slightly harsher treatments were used.

Ribonucleoprotein of Avian Infectious Bronchitis Virus

“…wt. about 50000 has been found in all cases (Bingham, 1975;Collins et al, 1976;Alexander & Collins, 1977;Macnaughton & Madge, 1977a;Macnaughton et aL, 1977;Nagy & Lomniczi, 1979;Lanser & Howard, 1980), and this is associated with the RNA genome (Macnaughton et al, 1977). Our RNP preparations from sucrose gradients contained such a polypeptide, identical in tool.…”

“…20 Ci/mmol) (The Radiochemical Centre, Amersham) were added just after infection. The cells were harvested after 25 h, subjected to three freeze-thaw cycles and were then clarified at 2000 g for 30 min at 4 °C (Macnaughton & Madge, 1977a).…”

Host Cell Nuclear Function and Murine Hepatitis Virus Replication

“…Also, MHV has a genome that is smaller than IBV (Lai & Stohlman, 1978;Wege et al, 1978;Spaan et al, 1981;Watkins et al, 1975;Lomniczi & Kennedy, 1977). In addition, MHV has four or five structural proteins (Wege et al, 1979;Anderson et al, 1979;Bond et al, 1979;MacNaughton, 1980), while IBV has six to sixteen structural proteins (Bingham, 1975;Alexander & Collins, 1977;MacNaughton & Madge, 1977;Nagy & Lomniczi, 1979). The data presented here regarding MHV imply a basic difference in the replication cycles of IBV and MHV and add further evidence of molecular differences within the Coronaviridae.…”

The Polypeptides of Infectious Bronchitis Virus (IBV-41 Strain)

“…wt. polypeptide species which is believed to be a major nucleocapsid component (Macnaughton et al 1977). Collins et al (I976) separated egg-grown virus into as many as five distinct populations of infectious virus by a combination of continuous and discontinuous sucrose gradient centrifugation steps.…”