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Enrichment of Bacterial Lipoproteins and Preparation of N-terminal Lipopeptides for Structural Determination by Mass Spectrometry
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N-Lipidated Peptide Dimers: Effective Antibacterial Agents against Gram-Negative Pathogens through Lipopolysaccharide

Jun-Jie Koh1,2, Huifen Lin1, Vonny Caroline1

  • 1Singapore Eye Research Institute, The Academia , 20 College Road, Discovery Tower Level 6, 169856, Singapore.

Journal of Medicinal Chemistry
|July 28, 2015
PubMed

Insights

New peptide dimers with fatty acid chains show potent activity against multidrug-resistant Gram-negative bacteria. These compounds effectively permeabilize the lipopolysaccharide (LPS) barrier and demonstrate low toxicity, offering a promising alternative to existing antibiotics.

Area of Science:

  • Medicinal Chemistry
  • Microbiology
  • Drug Discovery

Background:

  • Treating multidrug-resistant Gram-negative infections is challenging due to pathogen resistance and antimicrobial toxicity.
  • Existing treatments like polymyxin B have limitations regarding toxicity and efficacy.

Purpose of the Study:

  • To design and synthesize novel N-lipidated peptide dimers to combat Gram-negative pathogens.
  • To enhance antimicrobial potency by maximizing interaction with lipopolysaccharide (LPS) and facilitating LPS barrier permeabilization.

Main Methods:

  • Systematic design and synthesis of a series of N-lipidated peptide dimers.
  • Evaluation of LPS permeabilization and antimicrobial activity against Gram-negative bacteria, including carbapenem-resistant Enterobacteriaceae (CRE).
  • Assessment of synergistic effects with existing antibiotics and evaluation of toxicity (hemolytic, cellular, in vivo).

Main Results:

  • Optimized lipid chain length (6-10 carbons) demonstrated strong LPS permeabilization.
  • Developed compounds, particularly compound 23, showed synergy with antibiotics and rapid bactericidal activity.
  • Compounds 23 and 32 exhibited no hemolytic, cellular, or in vivo toxicity at tested concentrations.

Conclusions:

  • N-lipidated peptide dimers represent a promising new class of antimicrobials against multidrug-resistant Gram-negative pathogens.
  • These compounds overcome limitations of current therapies by effectively targeting the LPS barrier with low toxicity.
  • Further development of these peptide dimers could provide a vital new strategy for treating challenging Gram-negative infections.

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