Structure-activity relationships of cecropin-like peptides and their interactions with phospholipid membrane

Cecropin A and papiliocin are novel 37-residue cecropin-likeantimicrobial peptides isolated from insect. We have confirmedthat papiliocin possess high bacterial cell selectivity and has anα-helical structure from Lys3 to Lys21 and from Ala25 to Val35,linked by a hinge region. In this study, we demonstrated thatboth peptides showed high antimicrobial activities againstmulti-drug resistant Gram negative bacteria as well as fungi.Interactions between these cecropin-like peptides and phospholipidmembrane were studied using CD, dye leakageexperiments, and NMR experiments, showing that bothpeptides have strong permeabilizing activities against bacterialcell membranes and fungal membranes as well as Trp2 andPhe5 at the N-terminal helix play an important role in attractingcecropin-like peptides to the negatively charged bacterial cellmembrane. Cecropin-like peptides can be potent peptideantibiotics against multi-drug resistant Gram negative bacteriaand fungi. [BMB Reports 2013; 46(5): 282-287]