The Secretive Expression of Porcine Alpha-Interferon Gene in Pichia pastoris

In order to get alpha-interferon(INF-α) with high level secretive expression and high antiviral activities,the porcine alpha-interferon gene was amplified by PCR,and a DNA fragment of 501 bp,the open reading framework(ORF) was obtained.Then,the target gene and pPICZαC were digested with EcoRI/XbaI and were linked.The recombinant plasmid of pPICZαC-IFN was linearized by SacI and electroporated into Pichia pastoris X-33.PCR assay was used to identify colonies.The high copy recombinat strains were screened and induced by regulation of methanol utilization.IFN-α protein was detected by SDS-PAGE and Western-blotting analysis.The result showed the IFN-α protein with a raletive molecular mass of 19 400 was expressed in Pichia pastoris X-33.The antiviral activity of IFN-α against vesicular stomatitis virus(VSV) was investigated on the Vero cell and the result indicated that IFN-α could inhibit VSV and the activity was 4.04×106 IU/L.