Secreted Expression of the Combinant Antimicrobial Peptide PL in Pichia pastoris and Its Antibacterial Activity in vitro

Abstract:

In order to obtain a high activity antibacterial peptide，An expression vector pPICZαA-pl, is constructed with a tandem of four antimicrobial peptides in the same direction，which includes Protegrin-1(PG-1)、Scorpion Defensin(SD)、Metalnikowin-2A and Sheep Myeloid Antibacterial Peptide(SMAP-29) (serial number in GenBank are AAB27599，AAAB27538，P80409 and P49928 respectively). At the same time the expression vector pPICZαA-sd which express Scorpion Defensin was contructed. The expression vectors of pPICZαA-pl and pPICZαA-sd were linearized and transformed into the yeast host strain X-33 respectively. Under the control of the promoter AOX1(alcohol oxidase1)，the peptides PL and SD were secreted expressed. Their heat-stable property、acid-stable property and MIC were detected in vitro. The results suggest the peptides PL and SD have good heat-stable and acid stable properties，and the combinant PL peptide showes higher antibacterial activity against several Gram-positive bacteria(G⁺) and Gram-negative bacteria(G^-) than the peptide SD，especially against Escherichia coli. The antibacterial activity of combinant antimicrobial peptide PL shows its far exploiting perspective.