Unravelling the antifungal property of a type I crustin from Scylla olivacea: Membrane disruption and ROS generation as modes of action

Crustins, among the earliest families of gene-encoded antimicrobial peptides (AMPs) identified in crustaceans, are disulfide-rich peptides (6–22 kDa) characterized by a conserved Whey Acidic Protein (WAP) domain at the C-terminal end. This domain features a disulfide core formed by eight highly conserved cysteines. Functionally, crustins exhibit diverse biological roles. In this study, we demonstrate the in vitro antifungal efficacy and explore the mechanisms of action of So-Crustin, a Type-I crustin isoform derived from the Orange mud-crab Scylla olivacea. The recombinant peptide displayed potent antifungal activity, marked by rapid, membrane-targeted disruptions as nanoscale pores, <14 Å in size, accompanied by the production of reactive oxygen species (ROS) and substantial alterations to cellular membrane integrity, culminating in cell lysis. These results highlight So-Crustin as a promising antifungal agent with potential applications in the development of innovative antifungal therapies.