Secretory Expression of Bovine IL2 Gene in Pichia pastoris

The bovine Interleukin-2 gene was inserted into the Pichia pastoris expression vector pPICZαA which contains AOXI promoter and α-factor signal sequence.The recombinant plasmid of BoIL-2pPICZαA was linearnized by SacⅠ and transformed into X-33 and KM71H by electroporation.The recombinant Pichia strains.identified by PCR and Zeocin resistance were cultured and induced with methanol.SDS-PAGE analysis and Western blot showed BoIL-2 was expressed in a fused protein with the α-factor signal peptide but failed to secrete into medium.Effect of signal peptide and prefer codon on efficiency of secretory expression was also discussed in detail.