Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 1998
Publication Date: N/A
Technical Abstract: Bovine viral diarrhea virus (BVDV) is a member of the pestivirus genus of the Flavivirus family. Pestivirus virions consist of four structural proteins: the nucleocapsid (C) and three glycoproteins (Erns, E1 and E2). Neutralizing epitopes, found on the E2 glycoprotein, are dependent on the tertiary structure of the protein. Gene expression is believed to occur via synthesis of a polyprotein that is subsequently cleaved by viral and cell proteases into individual viral proteins. It has been proposed that the cleavage sites of the polyprotein are conserved among all pestiviruses. In contrast, this study suggests the cleavage sites that produce the E2 protein are not conserved among BVDV. Variation in molecular weight of the E2 glycoprotein, based on immunoprecipitation, was observed among BVDV isolates. Comparison of the sequences coding for the E2 glycoprotein did not reveal insertions or deletions that would account for differences in molecular weight. Variation in the molecular weight of the E2 protein backbone was observed after deglycosylation. This suggests that BVDV isolates differ in the way the polyprotein is cleaved to yield E2. Because differences in cleavage may affect tertiary structure variation in cleavage sites may result in antigenic differences.