[Production of antimicrobial peptide (Oxysterlin 1) in Escherichia coli with ELP self-cleavage tag].

Antimicrobial peptides are the most promising alternatives to antibiotics. However, the strategy of producing antimicrobial peptides by recombinant technology is complicated and expensive, which is not conducive to the large-scale production. Oxysterlin 1 is a novel type of cecropin antimicrobial peptide mainly targeting on Gram-negative bacteria and is of low cytotoxicity. In this study, a simple and cost-effective method was developed to produce Oxysterlin 1 in Escherichia coli. The Oxysterlin 1 gene was cloned into a plasmid containing elastin-like polypeptide (ELP) and protein splicing elements (intein) to construct the recombinant expression plasmid (pET-ELP-I-Oxysterlin 1). The recombinant protein was mainly expressed in soluble form in E. coli, and then the target peptide can be purified with a simple salting out method followed by pH changing. The final yield of Oxysterlin 1 was about 1.2 mg/L, and the subsequent antimicrobial experiment showed the expected antimicrobial activity. This study holds promise for large-scale production of antimicrobial peptides and the in-depth study of its antimicrobial mechanism.