Antimicrobial lipopeptide tridecaptin A1 selectively binds to Gram-negative lipid II

Proc Natl Acad Sci U S A. 2016 Oct 11;113(41):11561-11566. doi: 10.1073/pnas.1608623113. Epub 2016 Sep 29.


Tridecaptin A1 (TriA1) is a nonribosomal lipopeptide with selective antimicrobial activity against Gram-negative bacteria. Here we show that TriA1 exerts its bactericidal effect by binding to the bacterial cell-wall precursor lipid II on the inner membrane, disrupting the proton motive force. Biochemical and biophysical assays show that binding to the Gram-negative variant of lipid II is required for membrane disruption and that only the proton gradient is dispersed. The NMR solution structure of TriA1 in dodecylphosphocholine micelles with lipid II has been determined, and molecular modeling was used to provide a structural model of the TriA1-lipid II complex. These results suggest that TriA1 kills Gram-negative bacteria by a mechanism of action using a lipid-II-binding motif.

Keywords: antibiotic; lipid II; membrane pore; peptide; peptidoglycan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / metabolism
  • Anti-Bacterial Agents / pharmacology*
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Drug Resistance, Bacterial / drug effects
  • Escherichia coli / drug effects
  • Escherichia coli / growth & development
  • Kinetics
  • Lipids / chemistry*
  • Lipopeptides / chemistry
  • Lipopeptides / metabolism
  • Lipopeptides / pharmacology*
  • Magnetic Resonance Spectroscopy
  • Micelles
  • Microbial Sensitivity Tests
  • Models, Molecular
  • Peptides / chemistry
  • Peptides / metabolism
  • Peptides / pharmacology*
  • Proton-Motive Force


  • Anti-Bacterial Agents
  • Lipids
  • Lipopeptides
  • Micelles
  • Peptides
  • tridecaptins

Associated data

  • PDB/2n5w
  • PDB/2n5y