Expression and Characterization of truncated Non Structural Protein NS1 of Porcine Parvovirus in E.coli

Abstract

A gene fragment (1008bp) of Porcine Parvovirus (PPV) non-structural protein NS1 was amplified by PCR from tonsillar tissue sample. The amplicon was cloned and sequenced. The deduced amino acid sequences of the gene fragment showed more than 98% homology with published sequences. The NS1 gene fragment was subcloned into prokaryotic expression vector pET28a ( + ) and designated as pET-NS1. The recombinant plasmid was transformed into E.coli BL21(DE3) pLysS cells and the expression of the truncated recombinant NS1 (rNS1) protein with a size of 43kDa was induced with 1mM IPTG for four hours. The rNS1 protein was purified by affinity column chromatography under denaturing conditions and characterised by SDS-PAGE and Western blot. It reacted with PPV positive serum but not with PPV negative serum or Porcine Circovirus serum. The rNS1 protein can be used to develop tests to detect PPV antibodies in infected animals and also to differentiate it from animals vaccinated with inactivated vaccine as it is found only in virus-infected cells but not in mature virion.