This peptide is Protegrin-1 (PG-1) with a modified C-terminal amide. PG-1 is an 18-amino-acid beta-hairpin antimicrobial peptide found in porcine leukocytes and belongs to the cathelicidin family. PG-1 exhibits broad-spectrum activity unaffected by extracellular NaCl concentrations and is capable of inactivating numerous bacterial strains, Candida albicans, and some enveloped viruses. The efficacy is strongly dependent upon the existence of two disulfide bonds that stabilize the beta-sheet structure.