Antibacterial activities of temporin A analogs

Temporin A (TA) is a small, basic, highly hydrophobic, antimicrobial peptid e amide (FLPLIGRVLSGIL-NH2) found in the skin of the European red frog, Ran a temporaria. It has variable antibiotic activities against a broad spectru m of microorganisms, including clinically important methicillin-sensitive a nd -resistant Staphylococcus aureus as well as vancomycin-resistant Enteroc occus faecium strains. In this investigation the antimicrobial activity and structural characteristics of TA synthetic analogs were studied. For antib acterial activity against S: aureus and enterococcal strains, the hydrophob icity of the N-terminal amino acid of TA was found to be important as well as a positive charge at amino acid position 7, and bulky hydrophobic side c hains at positions 5 and It, Replacing isoleucine with leucine at amino aci d positions 5 and It resulted in the greatest enhancement of antibacterial activity. In addition, there was little difference between the activities o f TA and its all-D enantiomer, indicating that the peptide probably exerts its effect on bacteria,ia non-chiral interactions with membrane lipids. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier S cience B.V. All rights reserved.