Porcine parvovirus: virus purification and structural and antigenic properties of virion polypeptides

Abstract

Porcine parvovirus (PPV) was extensively purified from infected swine fetal homogenates by CaCl2 precipitation followed by CsCl density centrifugation. Two species of particles possessing PPV-specific hemagglutinating activity were observed banding at densities of 1.39 and 1.30 g/ml, representing full and empty 20-nm virion particles, respectively. Both classes of particles contained 3 major polypeptides, A, B and C, with respective MW of 83,000, 64,000 and 60,000. The amount of polypeptide A was similar in both species (.apprx. 10%) the B protein was most abundant in the 1.30-g/ml particles; the C protein was the major polypeptide found in the 1.39 g/ml particles. Antisera generated to each sodium dodecyl sulfate-polyacrylamide gel-purified virion structural protein had reactivities qualitatively similar to those of conventional antisera raised against intact PPV in a variety of standard serological assays. The antisera generated against the individual sodium dodecyl sulfate-denatured PPV polypeptides were able to react with native, intact PPV virions and were capable of neutralizing virus infectivity.