The polypeptide structure of canine coronavirus and its relationship to porcine transmissible gastroenteritis virus.

Canine coronavirus (CCV) isolate 1-71 was grown in secondary dog kidney cells and purified by rate zonal centrifugation. Polyacrylamide gel electrophoresis revealed four major structural polypeptides with apparent mol. wt. of 203800 (gp204), 49800 (p50), 31800 (gp32) and 21600 (gp22). Incorporation of 3H-glucosamine into gp204, gp32 and gp22 indicated that these were glycopolypeptides. Comparison of the structural polypeptides of CCV and porcine transmissible gastroenteritis virus (TGEV) by co-electrophoresis demonstrated that TGEV polypeptides corresponded closely, but not identically, with gp204, p50 and gp32 of CCV and confirmed that gp22 was a major structural component only in the canine virus. The close similarities in structure of the two coronaviruses augments the relationship established by serology.