Due to their broad-spectrum activity and distinct modes of action, antimicrobial peptides (AMPs) are considered as potential alternatives to combat the widespread adapting resistance of pathogens to conventional antibiotics1. Among them, the proline-rich AMPs (PrAMPs) family has been extensively studied as potential agents for a new generation of antibiotics2.
Previously, we showed by high resolution microscopy and flow cytometry that the alteration of mechanism of antibacterial action of a designed proline-rich antimicrobial peptide (PrAMP), Chex1-Arg20, with increasing valency from monomer to dimer and tetramer3. Furthermore, the effects of a series of N- and C-terminal modifications of the monomeric PrAMP, Chex1-Arg20, were studied on a panel of Gram-negative bacteria4. It was shown that C-terminal modifications with hydrazide or alcohol functions significantly extended their antibacterial activity against A. baumannii and P. aeruginosa. Thus, these engineered PrAMPs, modified Chex1-Arg20 and tetrameric highlight the value of solid phase synthesis to advance the development of novel compounds with strong activity against nosocomial Gram-negative bacteria (E. coli, K. pneumonia, A. baumannii and P.aeruginosa).