Functionalized antibacterial peptide with DNA cleavage activity for enhanced bacterial disinfection

Antibiotics are commonly used to treat bacterial infections, but the misuse and abuse of antibiotics have given rise to a severe problem of the drug resistance of bacteria. Solving this problem has been a vitally important task in the modern medical arena. Antibacterial peptide (AMPs) has become a promising candidate drug to replace antibiotics because of their broad-spectrum antibacterial activity and their difficulty in making bacteria resistant. However, its wider clinical application is limited by the shortcomings of high cytotoxicity and low antibacterial efficiency. In this paper, we constructed an antibacterial peptide (Cu-GGH-KKLRKIAFK, abbreviated as Cu-GGH-AMP) with a DNA cleavage function. The peptide has two functional regions, the C-terminal antibacterial peptide PaDBS1R6F10 (KKLRLKIAFK) and the N-terminal Cu-GGH complex. PaDBS1R6F10 is a unique antibacterial peptide, which shows lower tendency to produce bacterial resistance than traditional antibiotics. Cu-GGG complexes are formed by chelating Cu with the classical amino terminal Cu (II)- and Ni (II) -Binding (ATCUN) motif GGH. In the presence of ascorbic acid, Cu-GGH can efficiently catalyze the oxidative cleavage of bacterial DNA, thus playing a synergistic antibacterial role with antibacterial peptides. The in vitro and in vivo experiments demonstrated this functionalized antibacterial peptide possesses excellent antibacterial and anti-skin infection capability, as well as the activity of promoting wound healing.