Identification and characterization of differentiating soluble antigens of sheep and goat poxviruses

Soluble antigens of sheep and goat poxviruses (SPV, GPV) were isolated and purified from scab suspensions prepared from lesions of experimentally infected homologous hosts. The soluble antigens were then subjected to sequential ammonium sulphate precipitation. All the obtained fractions reacted in counter immunoelectrophoresis (CIE) with both the antisera against SPV and GPV except the fraction obtained at 30% saturation level (30% SSPV), which did not react with antiserum against GPV. This differentiating soluble SPV antigen was found to consist of 210 K proteins in exclusion chromatography. The 210 K proteins contained 3 polypeptides of 100, 35 and 17 K in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS-PAGE). The study thus gave an evidence that the SPV-specific proteins are of a higher molecular mass nature.