Expression, purification, and characterization of recombinant NS-1, the porcine parvovirus non-structural protein

The non-structural protein NS-1 of porcine parvovirus (PPV) could be a useful antigen for differentiating pigs infected with PPV from those vaccinated with inactivated whole virus. NS-1 was expressed in Escherichia coli using the pET-32a (+) vector. The fusion protein, which was expressed at a high level, was similar antigenically to the native NS-1 protein as determined by Western blot assay using polyclonal antibodies from pigs vaccinated with alive PPV vaccine. A simple procedure was used to purify the fusion protein. This research lays the foundation for using the NS-1 protein for clinical diagnosis of pigs infected with PPV vs. those vaccinated with inactivated whole virus vaccine.