Optimizing Antimicrobial Peptide Design: Integration of Cell-Penetrating Peptides, Amyloidogenic Fragments, and Amino Acid Residue Modifications.

The escalating threat of multidrug-resistant pathogens necessitates innovative approaches to combat infectious diseases. In this study, we examined peptides R23F*, V31K*, and R44K*, which were engineered to include an amyloidogenic fragment sourced from the S1 protein of , along with one or two cell-penetrating peptide (CPP) components. We assessed the antimicrobial efficacy of these peptides in a liquid medium against various strains of both Gram-positive bacteria, including (209P and 129B strains), MRSA (SA 180 and ATCC 43300 strains), and (strain IP 5832), and Gram-negative bacteria such as (ATCC 28753 and 2943 strains) and (MG1655 and K12 strains). Peptides R23F*, V31K*, and R44K* exhibited antimicrobial activity comparable to gentamicin and meropenem against all tested bacteria at concentrations ranging from 24 to 48 μM. The peptides showed a stronger antimicrobial effect against . Notably, peptide R44K* displayed high efficacy compared to peptides R23F* and V31K*, particularly evident at lower concentrations, resulting in significant inhibition of bacterial growth. Furthermore, modified peptides V31K* and R44K* demonstrated enhanced inhibitory effects on bacterial growth across different strains compared to their unmodified counterparts V31K and R44K. These results highlight the potential of integrating cell-penetrating peptides, amyloidogenic fragments, and amino acid residue modifications to advance the innovation in the field of antimicrobial peptides, thereby increasing their effectiveness against a broad spectrum of pathogens.