The natural antimicrobial cationic peptide protegrin-1 displays a broad spectrum of antimicrobial activity and rapidly kills pathogens by interacting with their cell membrane. We investigated the structure–activity relation-ships of three protegrin-1 analogues: IB-367 (RGGLCYCRGRFCVCVGR-NH2), BM-1 (RGLCYCRGRFCVCVG-NH2) and BM-2 (RGLCYRPRFV CVG-NH2). Our antimicrobial and antifungal activity studies of these peptides showed that BM-1 was much more active than IB-367 against Gram-positive bacteria and fungi, whereas BM-2 was inactive. .
