中国生物工程杂志

Abstract ：A 120bp DNA fragment encoding antibacterial peptide of sarcophaga peregrina A was designed based on the amino acid sequence of antibacterial peptide and the biased codon usage of pastoris．Eight oligonucleotides were chemically synthesized，linked and then recombinant with α-factor gene , recombinanted gene was cloned into yeast expression vector pPIC9K．After restriction enzyme analysis and DNA sequencing，the recombinanted gene of antibacterial peptide was transfected the Pichia pastoris GSll5 strain．The positive clones screened by the phenotype were induced by methanol , the expression product was tested by SDS-PAGE and inhibit zone using E.coli SD and E.coli C3000 as tested strain. The results showed that antibacterial peptide gene was expressed in Pichia pastoris successfully． The expression product was secreted outside with the lead of α-factor signal and had strong antibacterial activity．