Bovine coronavirus hemagglutinin protein.

Treatment of purified bovine coronavirus (Mebus strain) with pronase destroyed the integrity of virion surface glycoproteins gp140, gp120, gp100, reduced the amount of gp26 and destroyed the hemagglutinating activity of the virus. Bromelain, on the other hand, destroyed the integrity of gp120, gp100 and gp26 but failed to remove gp140 and failed to destroy viral hemagglutinating activity. These experiments suggest that gp140 is the virion hemagglutinin. Immunoblotting studies using monospecific antiserum demonstrate that gp140 is a disulfide-linked dimeric structure reducible to monomers of 65 kDa.