Hybrid peptides with dual-mechanism to combat bacterial infection by targeting bacterial membrane and DNA

Antimicrobial peptides (AMPs) are promising antibiotic alternatives with the potential to overcome bacterial drug resistance due to their unique bacteriostatic mechanisms, which differ from those of conventional antibiotics. To enhance the applicability of AMPs, this study explored the truncation and recombination of peptide fragments derived from PMAP-23 (bacterial cell membrane targeting) and PR-39 (bacterial intracellular targeting), linked via a GGG flexible hinge to construct hybrid peptides. Among them, PR-2 demonstrated potent antibacterial activity and low toxicity (TI = 143.82), along with a dual antimicrobial mechanism. PR-2 effectively penetrated bacterial membrane, compromising membrane integrity. Furthermore, the results of the intracellular mechanism experiments indicated that PR-2 disrupts the structure of double-stranded DNA, inhibits cellular respiration, reduces ATP production, and causes the accumulation of reactive oxygen species (ROS), ultimately resulting in bacterial cell death. Conclusively, the design of hybrid peptides combining AMPs with distinct mechanisms offers a straightforward and efficient strategy for the development of next-generation antimicrobial agents.