Structural polypeptides of the American (VR-2332) strain of porcine reproductive and respiratory syndrome virus

Abstract

The structural polypeptides of the isolate VR-2332 of porcine reproductive and respiratory syndrome virus were analyzed in sucrose gradient-purified virions. The virus had an average density of 1.15 g/cm³ and contained, by SDS-PAGE, three major polypeptides with apparent molecular weights of 15, 19 and 26–30 kDa, which were designated as nucleocapsid (N), matrix (M) and envelope (E), respectively. The predominant structural protein was N. N-glycosidase F digestion only affected E whereas O-glycosidase or endoglycosidase H digestion had no effect, suggesting that the viral glycoproteins contain only complex N-linked carbohydrates.