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Title: Melittin-induced cholesterol reorganization in lipid bilayer membranes

The peptide melittin, a 26 amino acid, cationic peptide from honey bee (Apis mellifera) venom, disrupts lipid bilayer membranes in a concentration-dependent manner. Rather than interacting with a specific receptor, the peptide interacts directly with the lipid matrix of the membrane in a manner dependent on the lipid composition. Here, a small-angle neutron scattering study of the interaction of melittin with lipid bilayers made of mixtures of dimyristoylphosphatidylcholine (DMPC) and cholesterol (Chol) is presented. Through the use of deuterium-labeled DMPC, changes in the distribution of the lipid and cholesterol in unilamellar vesicles were observed for peptide concentrations below those that cause pores to form. In addition to disrupting the in-plane organization of Chol, melittin produces vesicles having inner and outer leaflet compositions that depend on the lipid–Chol molar ratio and on the peptide concentration. The changes seen at high cholesterol and low peptide concentration are similar to those produced by alamethicin (Qian, S. et al., J. Phys. Chem. B 2014, 118, 11200–11208), which points to an underlying physical mechanism driving the redistribution of Chol, but melittin displays an additional effect not seen with alamethicin. Furthermore, a model for how the peptide drives the redistribution of Chol is proposed. The resultsmore » suggest that redistribution of the lipids in a target cell membrane by membrane active peptides takes places as a prelude to the lysis of the cell.« less
Authors:
 [1] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
OSTI Identifier:
1195805
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Biochimica et Biophysica Acta. Biomembranes
Additional Journal Information:
Journal Volume: 1848; Journal Issue: 10; Journal ID: ISSN 0005-2736
Publisher:
Elsevier
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES membrane active peptides; lipid bilayers; small-angle neutron scattering; melittin; cholesterol