Arginine and tryptophan-rich dendritic antimicrobial peptides that disrupt membranes for bacterial infection in vivo

Eur J Med Chem. 2024 May 5:271:116451. doi: 10.1016/j.ejmech.2024.116451. Epub 2024 Apr 27.

Abstract

The potent antibacterial activity and low resistance of antimicrobial peptides (AMPs) render them potential candidates for treating multidrug-resistant bacterial infections. Herein, a minimalist design strategy was proposed employing the "golden partner" combination of arginine (R) and tryptophan (W), along with a dendritic structure to design AMPs. By extension, the α/ε-amino group and the carboxyl group of lysine (K) were utilized to link R and W, forming dendritic peptide templates αRn(εRn)KWm-NH2 and αWn(εWn)KRm-NH2, respectively. The corresponding linear peptide templates R2nKWm-NH2 and W2nKRm-NH2 were used as controls. Their physicochemical properties, activity, toxicity, and stability were compared. Among these new peptides, the dendritic peptide R2(R2)KW4 was screened as a prospective candidate owing to its preferable antibacterial properties, biocompatibility, and stability. Additionally, R2(R2)KW4 not only effectively restrained the progression of antibiotic resistance, but also demonstrated synergistic utility when combined with conventional antibiotics due to its unique membrane-disruptive mechanism. Furthermore, R2(R2)KW4 possessed low toxicity (LD50 = 109.31 mg/kg) in vivo, while efficiently clearing E. coli in pulmonary-infected mice. In conclusion, R2(R2)KW4 has the potential to become an antimicrobial regent or adjuvant, and the minimalist design strategy of dendritic peptides provides innovative and encouraging thoughts in designing AMPs.

Keywords: Antibiotic resistance; Dendritic peptides; Membrane-disruptive mechanism; Minimalist design.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / chemical synthesis
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Antimicrobial Peptides / chemical synthesis
  • Antimicrobial Peptides / chemistry
  • Antimicrobial Peptides / pharmacology
  • Arginine* / chemistry
  • Arginine* / pharmacology
  • Bacterial Infections / drug therapy
  • Cell Membrane / drug effects
  • Dose-Response Relationship, Drug
  • Escherichia coli / drug effects
  • Humans
  • Mice
  • Microbial Sensitivity Tests*
  • Molecular Structure
  • Structure-Activity Relationship
  • Tryptophan* / chemistry
  • Tryptophan* / pharmacology

Substances

  • Tryptophan
  • Arginine
  • Anti-Bacterial Agents
  • Antimicrobial Peptides