Advanced

Effects of peptide hydrophobicity on its incorporation in phospholipid membranes - an NMR and ellipsometry study

Oradd, Greger; Schmidtchen, Artur LU and Malmsten, Martin (2011) In Biochimica et Biophysica Acta - Biomembranes 1808(1). p.244-252
Abstract
Effects of peptide hydrophobicity on lipid membrane binding, incorporation, and defect formation was investigated for variants of the complement-derived antimicrobial peptide CNY21 (CNYITELRRQHARASHLGLAR), in anionic 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE)/1-palmitoyl-2-oleoylphosphatidylglycerol (POPG) and zwitterionic 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) membranes. Using a method combination of, e.g., ellipsometry, CD, and fluorescence spectroscopy, it was shown that peptide adsorption, as well as peptide-induced liposome leakage and bactericidal potency against Escherichia coli and Pseudomonas aeruginosa, was promoted by increasing the hydrophobicity of CNY21 through either substituting the two histidines (H) in... (More)
Effects of peptide hydrophobicity on lipid membrane binding, incorporation, and defect formation was investigated for variants of the complement-derived antimicrobial peptide CNY21 (CNYITELRRQHARASHLGLAR), in anionic 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE)/1-palmitoyl-2-oleoylphosphatidylglycerol (POPG) and zwitterionic 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) membranes. Using a method combination of, e.g., ellipsometry, CD, and fluorescence spectroscopy, it was shown that peptide adsorption, as well as peptide-induced liposome leakage and bactericidal potency against Escherichia coli and Pseudomonas aeruginosa, was promoted by increasing the hydrophobicity of CNY21 through either substituting the two histidines (H) in CNY21 with more hydrophobic leucine (L) residues, or end-tagging with tritryptophan (WWW). Fluorescence spectroscopy revealed that both CNY21WWW and the WWW tripeptide localized to the polar headgroup region of these phospholipid membranes. Deuterium NMR experiments on macroscopically oriented membranes containing fully (palmitoyl) deuterated POPC (POPC-d(31)) demonstrated that both CNY21L and CNY21WWW induced disordering of the lipid membrane. In contrast, for cholesterol-supplemented POPC-d(31) bilayers, peptide-induced disordering was less pronounced in the case of CNY21L, indicating that the peptide is unable to partition to the interior of the lipid membrane in the presence of cholesterol. CNY21WWW, on the other hand, retained its membrane-disordering effect also for cholesterol-supplemented POPC-d(31). These findings were supported by pulsed field gradient NMR experiments where the lateral lipid diffusion was determined in the absence and presence of peptides. Overall, the results provide some mechanistic understanding to previously observed effects of peptide hydrophobization through point mutations and end-tagging, particularly so for complement-based antimicrobial peptides. (C) 2010 Elsevier B.V. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
AMP, Antimicrobial peptide, Ellipsometry, Liposome, Membrane, NMR
in
Biochimica et Biophysica Acta - Biomembranes
volume
1808
issue
1
pages
244 - 252
publisher
Elsevier
external identifiers
  • wos:000285853800026
  • scopus:78649787010
ISSN
0005-2736
DOI
10.1016/j.bbamem.2010.08.015
language
English
LU publication?
yes
id
ba3913f6-372b-44d5-a95d-81ec72f17fd4 (old id 1876438)
date added to LUP
2011-04-01 11:29:35
date last changed
2017-10-22 04:07:17
@article{ba3913f6-372b-44d5-a95d-81ec72f17fd4,
  abstract     = {Effects of peptide hydrophobicity on lipid membrane binding, incorporation, and defect formation was investigated for variants of the complement-derived antimicrobial peptide CNY21 (CNYITELRRQHARASHLGLAR), in anionic 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE)/1-palmitoyl-2-oleoylphosphatidylglycerol (POPG) and zwitterionic 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) membranes. Using a method combination of, e.g., ellipsometry, CD, and fluorescence spectroscopy, it was shown that peptide adsorption, as well as peptide-induced liposome leakage and bactericidal potency against Escherichia coli and Pseudomonas aeruginosa, was promoted by increasing the hydrophobicity of CNY21 through either substituting the two histidines (H) in CNY21 with more hydrophobic leucine (L) residues, or end-tagging with tritryptophan (WWW). Fluorescence spectroscopy revealed that both CNY21WWW and the WWW tripeptide localized to the polar headgroup region of these phospholipid membranes. Deuterium NMR experiments on macroscopically oriented membranes containing fully (palmitoyl) deuterated POPC (POPC-d(31)) demonstrated that both CNY21L and CNY21WWW induced disordering of the lipid membrane. In contrast, for cholesterol-supplemented POPC-d(31) bilayers, peptide-induced disordering was less pronounced in the case of CNY21L, indicating that the peptide is unable to partition to the interior of the lipid membrane in the presence of cholesterol. CNY21WWW, on the other hand, retained its membrane-disordering effect also for cholesterol-supplemented POPC-d(31). These findings were supported by pulsed field gradient NMR experiments where the lateral lipid diffusion was determined in the absence and presence of peptides. Overall, the results provide some mechanistic understanding to previously observed effects of peptide hydrophobization through point mutations and end-tagging, particularly so for complement-based antimicrobial peptides. (C) 2010 Elsevier B.V. All rights reserved.},
  author       = {Oradd, Greger and Schmidtchen, Artur and Malmsten, Martin},
  issn         = {0005-2736},
  keyword      = {AMP,Antimicrobial peptide,Ellipsometry,Liposome,Membrane,NMR},
  language     = {eng},
  number       = {1},
  pages        = {244--252},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta - Biomembranes},
  title        = {Effects of peptide hydrophobicity on its incorporation in phospholipid membranes - an NMR and ellipsometry study},
  url          = {http://dx.doi.org/10.1016/j.bbamem.2010.08.015},
  volume       = {1808},
  year         = {2011},
}