Repurpose the antimicrobial peptide Buforin II for plasmid transformation into Escherichia coli

Antimicrobial peptides Buforin II, derived from histone H2A, demonstrates strong cell-penetrating activity without cell lysis and strong affinity for internal cellular nucleic acids, making it a potential candidate for macromolecule delivery into bacteria. Herein, we designed a peptide that is the fusion of Buforin II and a polycation tail (KH)6 and assessed its efficiency in delivering plasmid (pGEX-RG-(TAG)5, 7,142 bp) into Escherichia coli OmniMAX. The peptide and plasmid were incubated at 25°C to form the complexes at various peptide concentrations from 5 to 50 µg/mL. After that, the complexes were incubated with the E. coli competent cells at 25°C. In comparison with the transformation efficiency and normalized transformation efficiency of conventional heat-shock method, a 1.28 and 7.83 times higher transformation efficiency, correspondingly, was achieved by using novel peptide-based delivery system at peptide concentration of 5 µg/mL. The cell viability of over 90% was displayed at peptide concentration of 5 µg/mL. This study can lead to the development of a transformation approach under mild conditions and an ideal tool for gene delivery.