Mechanisms of peptide-induced pore formation in lipid bilayers investigated by oriented 31P solid-state NMR spectroscopy

PLoS One. 2012;7(10):e47745. doi: 10.1371/journal.pone.0047745. Epub 2012 Oct 18.

Abstract

There is a considerable interest in understanding the function of antimicrobial peptides (AMPs), but the details of their mode of action is not fully understood. This motivates extensive efforts in determining structural and mechanistic parameters for AMP's interaction with lipid membranes. In this study we show that oriented-sample (31)P solid-state NMR spectroscopy can be used to probe the membrane perturbations and disruption by AMPs. For two AMPs, alamethicin and novicidin, we observe that the majority of the lipids remain in a planar bilayer conformation but that a number of lipids are involved in the peptide anchoring. These lipids display reduced dynamics. Our study supports previous studies showing that alamethicin adopts a transmembrane arrangement without significant disturbance of the surrounding lipids, while novicidin forms toroidal pores at high concentrations leading to more extensive membrane disturbance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alamethicin / chemistry*
  • Anti-Infective Agents / chemistry*
  • Antimicrobial Cationic Peptides / chemistry*
  • Dimyristoylphosphatidylcholine / chemistry
  • Lipid Bilayers / chemistry*
  • Models, Chemical
  • Molecular Conformation
  • Nuclear Magnetic Resonance, Biomolecular

Substances

  • Anti-Infective Agents
  • Antimicrobial Cationic Peptides
  • Lipid Bilayers
  • novicidin
  • Alamethicin
  • Dimyristoylphosphatidylcholine

Grants and funding

Support from the Danish National Research Foundation, the Danish Natural Science Research Council, Lundbeckfonden, the Danish Center for Scientific Computing (DCSC), and the Danish Biotechnology Instrument Centre (DABIC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.