The Temporins

The temporin family of peptides is one of the smallest antimicrobial peptides to be found in nature. Temporins are composed of 10 and 14 amino acid residues. They are hydrophobic, C-terminally α-amidated peptides with antibacterial and antifungal properties that are synthesized in the skin of a wide range of North American and Eurasian frogs of the genus Rana. However, not all temporins are cationic, but a positive charge is an important determinant of antimicrobial potency. The temporins show potential for development into therapeutically valuable anti-infective agents, particularly for use against antibiotic-resistant Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis, against anaerobic pathogens such as Clostridium difficile, and against the protozoan Leishmania spp. However, the clinical usefulness of certain temporins is restricted by their high hemolytic activity. Individual temporins have been shown to stimulate hemotaxis of neutrophils and monocytes, modulate the activity of secretory phospholipase A₂, and relax vascular smooth muscle.