Novel Hybrid Peptide Cecropin A (1–8)-LL37 (17–30) with Potential Antibacterial Activity

Hybridizing different antimicrobial peptides (AMPs) is a particularly successful approach to obtain novel AMPs with increased antimicrobial activity but minimized cytotoxicity. The hybrid peptide cecropin A (1–8)-LL37 (17–30) (C-L) combining the hydrophobic N-terminal fragment of cecropin A (C) with the core antimicrobial fragment of LL37 (L) was designed and synthesized. C-L showed higher antibacterial activity against all indicator strains than C and L, and no hemolytic activity to sheep erythrocytes was observed. C-L kills bacterial cells and causes disruption of surface structure, as determined by scanning electron microscopy. Synergistic effects were observed in the combination of C-L with several antibiotics (chloramphenicol, thiamphenicol, or neomycin sulfate) against Escherichia coli and Staphylococcus aureus.