Computational Design of Pore-Forming Peptides with Potent Antimicrobial and Anticancer Activities

Peptides that form
transmembrane barrel-stave pores are potential
alternative therapeutics for bacterial infections and cancer. However,
their optimization for clinical translation is hampered by a lack
of sequence-function understanding. Recently, we have de novo designed the first synthetic barrel-stave pore-forming antimicrobial
peptide with an identified function of all residues. Here, we systematically
mutate the peptide to improve pore-forming ability in anticipation
of enhanced activity. Using computer simulations, supported by liposome
leakage and atomic force microscopy experiments, we find that pore-forming
ability, while critical, is not the limiting factor for improving
activity in the submicromolar range. Affinity for bacterial and cancer
cell membranes needs to be optimized simultaneously. Optimized peptides
more effectively killed antibiotic-resistant ESKAPEE bacteria at submicromolar
concentrations, showing low cytotoxicity to human cells and skin model.
Peptides showed systemic anti-infective activity in a preclinical
mouse model of Acinetobacter baumannii infection. We also demonstrate peptide optimization for pH-dependent
antimicrobial and anticancer activity.