Effect of antimicrobial peptide on dynamics of phosphocholine membrane: role of cholesterol and physical state of bilayer
Antimicrobial peptides are universal in all forms of life and are well known for their strong interaction with the cell membrane. This makes them a popular target for investigation of peptide-lipid interactions. Here we report the effect of melittin, an important antimicrobial peptide, on the dynamics of membranes based on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid in both the solid gel and fluid phases. To probe the phase transition, elastic neutron intensity temperature scans have been carried out on DMPC-based unilamellar vesicles (ULV) with and without melittin. We have found that addition of a small amount (0.2 mol%) melittin eliminates the steep fall in the elastic intensity at 296 K associated with the solid gel to fluid phase transition, which is observed for pure DMPC vesicles. Quasielastic neutron scattering (QENS) experiments have been carried out on DMPC ULV in the solid gel and fluid phases with and without 0.2 mol % melittin. The data analysis invariably shows the presence of lateral and internal motions of the DMPC molecule. We found that melittin does have a profound effect on the dynamics of lipid molecules, especially on the lateral motion, and affects it in a different way, depending on the phase of the bilayers. Inmore »
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Div.; Bhabha Atomic Research Centre (BARC), Mumbai (India). Solid State Physics Div.
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Div.
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biology and Soft Matter Div.
- Publication Date:
- Grant/Contract Number:
- Accepted Manuscript
- Journal Name:
- Soft Matter
- Additional Journal Information:
- Journal Volume: 11; Journal Issue: 11; Journal ID: ISSN 1744-683X
- Royal Society of Chemistry
- Research Org:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
- Sponsoring Org:
- USDOE Office of Science (SC)
- Country of Publication:
- United States
- 59 BASIC BIOLOGICAL SCIENCES; Antimicrobial peptides; Melittin; Neutron scattering; DMPC; Cholesterol
- OSTI Identifier: