Interferon Induction by Single-stranded Polynucleotides Modified with Polybases

Abstract

Methods for the purification of African swine fever virus (ASFV) and its dissection into two fractions are described. The difficulties which have been encountered previously in attempts to purify the virus, namely contamination with large amounts of cellular constituents and aggregation of the virus particles, have been overcome by treatment with Tween 80 and by the use of 1m-NaCl in the sucrose gradients. Five major polypeptides, mol. wt. 10³ × 125 (VP₁), 76 (VP₂), 50 (VP₃), 44 (VP₄) and 39 (VP₅) were found in the purified particles. The virus was dissected by treatment with Nonidet NP 40 into (a) a fraction which had the appearance of an empty capsid shell and contained the polypeptides VP₂ and VP₃ and (b) a structure containing VP₁ and VP₄. The location of VP₅ was not ascertained.