Identification of a novel antimicrobial peptide, scolopendin 1, derived from centipede S colopendra subspinipes mutilans and its antifungal mechanism

In this study, a novel antimicrobial peptide, scolopendin 1, was identified from adult centipedes, Scolopendra subspinipes mutilans using RNA sequencing. Scolopendin 1 exerted an antimicrobial activity without inducing haemolysis of human erythrocytes. In order to understand the antifungal mechanism, a reactive oxygen species ( ROS ) assay was performed, which indicated that scolopendin 1 induced ROS accumulation in C andida albicans . Evaluation of fungal viability using N ‐acetyl cysteine, a ROS scavenger, suggested that ROS are a major factor in scolopendin 1‐induced fungal cell death. Co‐staining of annexin V ‐fluorescein isothiocyanate ( FITC ) and propidium iodide, and TUNEL and 4′,6‐diamidino‐2‐phenylindole ( DAPI) assays confirmed that ROS ‐induced fungal cell death is associated with apoptosis. To further investigate the mechanism that facilitates the progression of apoptosis, changes in intracellular Ca 2+ concentration and mitochondrial dysfunction were examined. Ca 2+ , a signalling molecule in the apoptotic pathway, was increased in the cytosol and mitochondria, and ROS accumulation triggered mitochondrial depolarization and the release of cytochrome c , a pro‐apoptotic factor, from the mitochondria to the cytosol. Finally, the released cytochrome c activated intracellular caspase. The present study suggests that scolopendin 1 could emerge as a model molecule that targets the apoptotic pathway and provides a novel remedy.