Production of antimicrobial peptide arasin-like Sp in Escherichia coli via an ELP-intein self-cleavage system

Antibiotic resistance is a major public health threat to both humans and animals. There is an urgent need for antimicrobial agents with novel modes of action. Antimicrobial peptides (AMPs) with broad-spectrum antimi-crobial activity become the ideal alternative to traditional antibiotics. Here, the ELP-intein self-cleavage system was used to produce antimicrobial peptide arasin-likeSp in Escherichia coli. The tagged target protein (ELP-intein-arasin-likeSp) was mainly expressed in soluble, separated from cell lysates by the inverse transition cycling (ITC), and the arasin-likeSp was further purified by the self-cleavage of intein and the second round of ITC. The final yield of arasin-likeSp was about 3.56 mg/L. Purified arasin-likeSp exhibited significant antibacterial activities against the Gram-positive Bacillus subtilis and Gram-negative Vibrio harveyi bacteria. FE-SEM and PI staining analysis revealed that the arasin-likeSp treatment altered the morphology and membrane permeability of Bacillus subtilis and Vibrio harveyi. Collectively, these data suggest that arasin-likeSp is a candidate AMP for effective inhibition of Vibrio harveyi, a significant bacterial pathogen infecting marine fish and invertebrates. The ELP-intein self-cleavage system described here is a low-cost, simple and potential method for producing antimicro-bial peptides, which lays foundations for the large-scale production of antimicrobial peptides in the future.