Influence of the papiliocin peptide derived from Papilio xuthus on the perturbation of fungal cell membranes.

Papiliocin is a 37-residue peptide isolated from the swallowtail butterfly Papilio xuthus. In this study, the antifungal effects and the mechanism of actions of papiliocin were investigated. First of all, papiliocin was shown to exert fungicidal activity. To understand the antifungal mechanism(s), propidium iodide influx into Candida albicans cells, induced by papiliocin, was examined. The result indicated that papiliocin perturbed and disrupted the fungal plasma membrane. Furthermore, calcein leakage from large unilamellar vesicles and rhodamine leakage from giant unilamellar vesicles further confirmed and visualized the membrane-disruptive action of papiliocin in the fungal model membrane, respectively. In summary, the present study suggests that papiliocin exerts its antifungal activity by a membrane-active mechanism and that this peptide can be developed into novel potent antifungal agents.