Abstract
Inelastic neutron scattering was used to study the effect of 5 and 40 mol% cholesterol on the lateral nanoscale dynamics of phospholipid membranes. By measuring the excitation spectrum at several lateral q|| values (up to q|| = 3 A -1), complete dispersion curves were determined of gel, fluid and liquid-ordered phase bilayers. The inclusion of cholesterol had a distinct effect on the collective dynamics of the bilayer's hydrocarbon chains; specifically, we observed a pronounced stiffening of the membranes on the nanometer length scale in both gel and fluid bilayers, even though they were experiencing a higher degree of molecular disorder. Also, for the first time we determined the nanoscale dynamics in the highcholesterol liquid-ordered phase of bilayers containing cholesterol. Namely, this phase appears to be ''softer'' than fluid bilayers, but better ordered than bilayers in the gel phase.
| Original language | English |
|---|---|
| Pages (from-to) | 901-913 |
| Number of pages | 13 |
| Journal | European Biophysics Journal |
| Volume | 41 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2012 |
Funding
Acknowledgments This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the National Research Council Canada (NRC), the Canada Foundation for Innovation (CFI) and the Ontario Ministry of Economic Development and Innovation. John Katsaras is supported by Oak Ridge National Laboratory’s (ORNL) Program Development (PD) and Laboratory Directed Research and Development (LDRD) programs.
Keywords
- Cholesterol
- Dispersion relation
- Inelastic neutron scattering
- Lateral membrane dynamics
- Lipid membrane
- Liquidordered phase
- Nanoscale dynamics