Expression and purification of two different antimicrobial peptides, PR-39 and Protegrin-1 in Escherichia coli

To implement coexpression of antimicrobial peptides PR-39 and Protegrin-1 (PG-1) in prokaryotic expression system, a tandem gene fragment encoding PR-39 and PG-1 has been synthesized chemically. The cleavage site (Asn-Gly) of hydroxylamine hydrochloride was introduced between PR-39 and PG-1. The fragment was inserted into vector pGEX-4T-1 and expressed in Escherichia coli. The fusions of single peptides to GST were created at the same time. The fusion protein GST-PR-39-PG-1, purified by affinity chromatography, was cleaved first by hydroxylamine hydrochloride to release recombinant PG-1 and then by enterokinase to release PR-39. Purification of recombinant PR-39 and PG-1 was achieved. About 1.9 mg/l recombinant PR-39 and 1.1 mg/l PG-1 were obtained. The recombinant antimicrobial peptides showed antibacterial activities that were similar to those released from fusions of single peptides to GST.