Structure and membrane interactions of the antibiotic peptide dermadistinctin K by multidimensional solution and oriented 15N and 31P solid-state NMR spectroscopy

Biophys J. 2009 Mar 18;96(6):2194-203. doi: 10.1016/j.bpj.2008.11.063.


DD K, a peptide first isolated from the skin secretion of the Phyllomedusa distincta frog, has been prepared by solid-phase chemical peptide synthesis and its conformation was studied in trifluoroethanol/water as well as in the presence of sodium dodecyl sulfate and dodecylphosphocholine micelles or small unilamellar vesicles. Multidimensional solution NMR spectroscopy indicates an alpha-helical conformation in membrane environments starting at residue 7 and extending to the C-terminal carboxyamide. Furthermore, DD K has been labeled with (15)N at a single alanine position that is located within the helical core region of the sequence. When reconstituted into oriented phosphatidylcholine membranes the resulting (15)N solid-state NMR spectrum shows a well-defined helix alignment parallel to the membrane surface in excellent agreement with the amphipathic character of DD K. Proton-decoupled (31)P solid-state NMR spectroscopy indicates that the peptide creates a high level of disorder at the level of the phospholipid headgroup suggesting that DD K partitions into the bilayer where it severely disrupts membrane packing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimicrobial Cationic Peptides / chemistry*
  • Anura
  • Circular Dichroism
  • Lipid Bilayers / chemistry
  • Micelles
  • Models, Molecular
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular
  • Phosphatidylcholines
  • Phosphorus Isotopes
  • Phosphorylcholine / analogs & derivatives
  • Phosphorylcholine / chemistry
  • Protein Conformation
  • Sodium Dodecyl Sulfate / chemistry
  • Trifluoroethanol / chemistry
  • Unilamellar Liposomes / chemistry*
  • Water / chemistry


  • Antimicrobial Cationic Peptides
  • Lipid Bilayers
  • Micelles
  • Nitrogen Isotopes
  • Phosphatidylcholines
  • Phosphorus Isotopes
  • Unilamellar Liposomes
  • dermadistinctin K, Phyllomedusa distincta
  • Water
  • Phosphorylcholine
  • Sodium Dodecyl Sulfate
  • dodecylphosphocholine
  • Trifluoroethanol
  • 1-palmitoyl-2-oleoylphosphatidylcholine