A Versatile Approach to Noncanonical, Dynamic Covalent Single- and Multi-Loop Peptide Macrocycles for Enhancing Antimicrobial Activity

J Am Chem Soc. 2018 Mar 14;140(10):3768-3774. doi: 10.1021/jacs.8b00046. Epub 2018 Mar 1.

Abstract

Peptide oligomers offer versatile scaffolds for the formation of potent antimicrobial agents due to their high sequence versatility, inherent biocompatibility, and chemical tunability. Though many methods exist for the formation of peptide-based macrocycles (MCs), increasingly pervasive in commercial antimicrobial therapeutics, the introduction of multiple looped structures into a single peptide oligomer remains a significant challenge. Herein, we report the utilization of dynamic hydrazone condensation for the versatile formation of single-, double-, and triple-loop peptide MCs using simple dialdehyde or dihydrazide small-molecule cross-linkers, as confirmed by MALDI-TOF MS, HPLC, and SDS-PAGE. Furthermore, incorporation of aldehyde-containing side chains onto peptides synthesized from hydrazide C-terminal resins resulted in tunable peptide MC assemblies formed directly upon resin cleavage post solid-phase peptide synthesis. Both of these types of dynamic covalent assemblies produced significant enhancements to overall antimicrobial properties when introduced into a known antimicrobial peptide, buforin II, when compared to the original unassembled sequence.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / pharmacology*
  • Bacteria / drug effects
  • Bacterial Infections / drug therapy
  • Chemistry Techniques, Synthetic / methods
  • Humans
  • Macrocyclic Compounds / chemical synthesis
  • Macrocyclic Compounds / chemistry*
  • Macrocyclic Compounds / pharmacology*
  • Peptides / chemical synthesis
  • Peptides / chemistry*
  • Peptides / pharmacology*
  • Proteins / pharmacology

Substances

  • Anti-Bacterial Agents
  • Macrocyclic Compounds
  • Peptides
  • Proteins
  • buforin II