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bioRxiv · 10.1101/2022.12.01.518642

Optimization of host cell-compatible, antimicrobial peptides effective against biofilms and clinical isolates of drug-resistant bacteria.

Ghimire, J.·Hart, R. J.·Soldano, A.·Chen, C.·Guha, S.·Hoffmann, J. P.·Hall, K.·Sun, L.·Nelson, B. J.·Lu, T. K.·Kolls, J. K.·Rivera, M.·Morici, L. A.·Wimley, W. C.
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Abstract

Here, we describe the continued synthetic molecular evolution of a lineage of host-compatible antimicrobial peptides (AMP) intended for the treatment of wounds infected with drug-resistant, biofilm-forming bacteria. The peptides tested are variants of an evolved AMP called D-CONGA, which has excellent antimicrobial activities in vitro and in vivo. In this newest generation of rational D-CONGA variants, we tested multiple sequence-structure-function hypotheses that had not been tested in previous generations. Many of the peptide variants have lower antibacterial activity against Gram-positive or Gram-negative pathogens, especially variants that have altered hydrophobicity, secondary structure potential, or spatial distribution of charged and hydrophobic residues. Thus, D-CONGA is generally well tuned for antimicrobial activity. However, we identified a variant, D-CONGA-Q7, with a polar glutamine inserted into the middle of the sequence, that has higher activity against both planktonic and biofilm-forming bacteria as well as lower cytotoxicity against human fibroblasts. Against clinical isolates of K. pneumoniae, innate resistance to D-CONGA was surprisingly common despite a lack of inducible resistance in P. aeruginosa reported previously. Yet, these same isolates were susceptible to D-CONGA-Q7. D-CONGA-Q7 is much less vulnerable to AMP resistance in Gram-negative bacteria than its predecessor. Consistent with the spirit of synthetic molecular evolution, D-CONGA-Q7 achieved a critical gain-of-function and has a significantly better activity profile.

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Ghimire, J., Hart, R. J., Soldano, A., Chen, C., Guha, S., Hoffmann, J. P., Hall, K., Sun, L., Nelson, B. J., Lu, T. K., Kolls, J. K., Rivera, M., Morici, L. A., Wimley, W. C.. 2022-12-01. Optimization of host cell-compatible, antimicrobial peptides effective against biofilms and clinical isolates of drug-resistant bacteria.. https://doi.org/10.1101/2022.12.01.518642

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