Fusion expression of porcine interferon-gamma protein gene and bioactivities of its expressed protein

A pair of primers were designed according to the sequence of porcine IFN-γ mature protein gene.Then the amplified gene was cloned into pGEX-4T-1 vector and the fusion expression vector GST-pIFN-γ was constructed.The recombinant vector was transformed into Escherichia coli strain BL21.The recombinant strain was induced by IPTG and the induction conditions were optimized.Under the optimized conditions,the fusion protein GST-pIFN-γ was expressed.The soluble product was purified by GST aga-rose gel.The inclusion bodies were washed by DOC,and dissolved in SKL and subsequently renatured by dislysis.The purified recombinant protein was analyzed by SDS-PAGE and Western-blotting.The results showed that the purified fusion protein GST-pIFN-γ was obtained,and the recombinant protein was approximately 42 ku in molecular mass.The antiviral activity of the protein was determined by inhibiting the cytopathic effect,and the result showed that the fusion protein could suppress the cytopathic effect caused by FMDV(RNA virus) and PRV(DNA virus),and the anti-FMDV activity was higher than that of anti-PRV.In addition,the GST-pIFN-γ had the better stability and lower side effect.