Abstract
Recent advances in molecular simulations have stimulated new discussions on the molecular mechanisms of lateral diffusion of lipids in fluid bilayers. To enable a deeper comparison between theory and experiments, we conducted a systematic study of lateral diffusion rates for a series of phosphatidylcholines with 14, 16, 18 and 20 hydrocarbons per chain over the temperature range from 10 to 600C. Bilayers of the pure lipids as well as binary mixtures with 30 mol% cholesterol were investigated. Diffusion coefficients were measured by 1H MAS NMR with application of pulsed magnetic field gradients. All lipids had saturated, perdeuterated sn-1 chains that enabled measurement of chain order parameters by 2H NMR. From the average chain order parameters effective hydrophobic thicknesses of bilayers and lateral areas per lipid molecule were calculated. This enabled a quantitative comparison of experimentally determined and calculated lateral diffusion rates as a function of chain length, cholesterol content and temperature using a free-volume model of lateral diffusion. The implications of this comparison for models of lateral lipid diffusion will be discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.