Antimicrobial peptides are produced by plants and most organisms throughout the animal kingdom including humans. Antimicrobial peptides protect against a broad range of infectious agents, as bacteria, fungi, and viruses. The amphibian skin is an especially rich source of antimicrobial peptides. See also the product families: Hepcidins LL-37 and Fragments Tuftsin and Analogs (subfamily).
Magainin II belongs to a naturally occurring class of non-hemolytic vertebrate peptides with potent antibiotic properties, originally isolated from frog skin. At concentrations over 2 µM, it causes a change in membrane permeability and forms cation-selective channels.