Journal
JOURNAL OF LIPID RESEARCH
Volume 53, Issue 3, Pages 421-429Publisher
ELSEVIER
DOI: 10.1194/jlr.M022491
Keywords
flip-flop; molecular dynamics; lipid bilayer; free energy; desorption; lipid second-messenger
Categories
Funding
- Natural Sciences and Engineering Research Council (NSERC)
- Alberta Innovates Health Solutions (AIHS)
- Killam Trust
Ask authors/readers for more resources
The translocation of lipids across membranes (flip-flop) is an important biological process. Slow exchange on a physiological timescale allows the creation of asymmetric distributions of lipids across cellular membranes. The location of lipids and their rate of exchange have important biological consequences, especially for lipids involved in cellular signaling. We investigated the translocation of cholesterol, ceramide, and diacylglycerol in two model bilayers using molecular dynamics simulations. We estimate half times for flip-flop for cholesterol, diacylglycerol, and ceramide of 20 mu s, 30 mu s, and 10 ms in a POPC bilayer, compared with approximately 30 min, 30 ms, and 30 s in a model raft bilayer (1:1:1 PSM, POPC, and cholesterol). Cholesterol has a large (54 kJ/mol) free energy of exchange between the POPC and raft bilayer, and therefore, it strongly prefers the more ordered and rigid raft bilayer over the more liquid POPC bilayer. Ceramide and diacylglycerol have relatively small free energies of exchange, suggesting nearly equal preference for both bilayers. This unexpected result may have implications for ceramide and diacylglycerol signaling and membrane localization.-Bennett, W. F. D, and D. P. Tieleman. Molecular simulation of rapid translocation of cholesterol, diacylglycerol, and ceramide in model raft and nonraft membranes. J. Lipid Res. 2012. 53: 421-429.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available