The antibacterial activity of peptide dendrimers and polymyxin B increases sharply above pH 7.4

Chem Commun (Camb). 2021 Jun 8;57(46):5654-5657. doi: 10.1039/d1cc01838h.

Abstract

pH-activity profiling reveals that antimicrobial peptide dendrimers (AMPDs) kill Klebsiella pneumoniae and Methicillin-resistant Staphylococcus aureus (MRSA) at pH = 8.0, against which they are inactive at pH = 7.4, due to stronger electrostatic binding to bacterial cells at higher pH. A similar effect occurs with polymyxin B and might be general for polycationic antimicrobials.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Dendrimers / chemistry
  • Dendrimers / pharmacology*
  • Hydrogen-Ion Concentration
  • Klebsiella pneumoniae / drug effects*
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Microbial Sensitivity Tests
  • Molecular Conformation
  • Molecular Dynamics Simulation
  • Peptides / chemistry
  • Peptides / pharmacology*
  • Polymyxin B / chemistry
  • Polymyxin B / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Dendrimers
  • Peptides
  • Polymyxin B