Cloning and expression of human α-defensin gene in Pichia Pastoris yeast

This study focused on the expression of human α-defensin(HNP2) gene in Pichia yeast system.Human HNP2 cDNA was cloned based on the published sequence and the biased codon usage of Pichia yeast.The modified HNP2 cDNA was inserted into yeast expression vector pGAPZα.The plasmid pGAPZαANP2 was produced in E.coli HB109 and used for yeast transformation.Pichia pastoris SMD1168 was transformed with Bln I digested pGAPZαA-HNP2 and positive yeast clones were selected with PCR.The expression of HNP2 and the production of the recombinant HNP2 protein was purified with ion-exchange column were detected with SDS-PAGE and Western blotting,and quantified with Bradford and then used for biological activity assay.Our results demonstrated that the recombinant HNP2 had antimicrobial activity.These findings have provided valuable tools for further studies on the function and medicinal application of HNP2.