The Polypeptide Structure of Canine Coronavirus and its Relationship to Porcine Transmissible Gastroenteritis Virus

Abstract

Canine coronavirus (CCV) isolate 1-71 was grown in secondary dog kidney cells and purified by rate zonal centrifugation. Polyacrylamide gel electrophoresis revealed 4 major structural polypeptides with apparent MW of 203,800 (gp204), 49,800 (p50), 31,800 (gp32) and 21,600 (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 2 coronaviruses augments the relationship established by serology.