A Novel Antimicrobial Peptide Derived from the Insect Paederus dermatitis

Much research has been focused on antimicrobial peptides (AMPs) derived from insect immune defense reactions due to their potential in the development of new antibiotics. In this study, a new AMP from the insect Paederus dermatitis, named sarcotoxin Pd was identified and purified using gel filtration and reverse-phase high-performance liquid chromatography. Our results showed that this peptide has broad-spectrum inhibitory effects on examined microbes. Sarcotoxin Pd is composed of 34 amino acids and its molecular weight was estimated to be 3613.26 ± 0.5 Da. Minimum inhibitory concentration (MIC) values of sarcotoxin Pd against Gram-negative bacteria were lower than Gram-positive bacteria and fungi. The identified peptide showed the highest antimicrobial effect against Klebsiella pneumonia and Escherichia coli. This peptide did not reveal significant hemolytic activity against human red blood cells particularly in the range of MIC values. Confirming the potential antimicrobial activities of synthetic peptide, this paper addresses the role of sarcotoxin Pd in the treatment of systemic microbial illnesses.