A versatile bacterial membrane-binding chimeric peptide with enhanced photodynamic antimicrobial activity.

Photodynamic therapy (PDT) has become an effective antibiosis method for overcoming antibiotic resistance. In this study, we developed a versatile bacterial membrane-binding chimeric peptide PpIX-[PEG-(KLAKLAK)] (denoted as PPK) by conjugating a photosensitizer protoporphyrin IX (PpIX) with an antimicrobial peptide (KLAKLAK) (KLA) for effective photodynamic inactivation of bacteria. The chimeric peptide PPK with positively charged properties and an α-helical conformation could rapidly bind to microbial cells through electrostatic interactions and membrane insertion.