Structural and Functional Versatility of the Amyloidogenic Non-Amidated Variant of the Antimicrobial Peptide Citropin 1.3.

ABSTRACT: Citropin 1.3 is an antimicrobial peptide secreted by the amphibian Litoria citropa (Southern bell frog). In this study, the structural and functional properties of its non-amidated form, which self-assembles into distinct fibrillar architectures, are investigated. Using cryogenic electron microscopy, X-ray crystallography, and fluorescence microscopy with model membranes and cells, diverse supramolecular structures, including canonical amyloid fibrils, multilayered nanotubes, and a novel mixed fibril type, are identified. In giant unilamellar vesicles, citropin 1.3 promoted membrane fusion and underwent lipid-induced phase separation. In mammalian cells, it permeabilized membranes, induced cell death, and colocalized with nucleic acids. These findings link antimicrobial activity to amyloid

SUBMITTER: Strati F 

PROVIDER: S-EPMC12697819 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature