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).
SPF, the hydrophobic 13-residue fragment (28-40) of the antimicrobial peptide seminalplasmin, possesses antibacterial and hemolytic activities. SPFK, the SPF analog in which Glu³² has been replaced by Lys, exhibits potent antibacterial activity at concentrations at which erythrocyte lysis does not occur.