Expression and Purification of Consensus Interferon in Pichia pastoris

To obtain high level secretive expressed con-IFN in Pichia pastoris,the DNA of con-IFN was amplified by recursive PCR,digested with EcoR Ⅰand Not Ⅰ,then cloned into the secretory expression vector pGAPZαA.The recombinant vector was linearized,and transformed into GS115 through high efficiency transformation and Zeocin selection,the recombinant strains of pGAP-conIFN/GS115 were obtained.SDS-PAGE analysis suggested the recombinant protein was secreted into culture medium.The culture supernatant was purified through salt out,size exclude chromatography and ion exchange,the purity of recombinant protein reached 92%,purified recombinant con-IFN had a specific antiviral activity of about 5.5×108 U/mg.