Lipid bilayers, NMR relaxation, and computer simulations.
Brownian and molecular dynamics simulations of a lipid bilayer are described, and the calculated frequency-dependent (13)C NMR T(1) relaxation times are compared with experiment. A consistent model emerges. Through fast internal motions, individual lipids average themselves into relatively cylindrical shapes on the 100 ps time scale and "wobble" in a cone-like potential on the nanosecond time scale. These motions take place in a highly fluid environment, much like a liquid alkane. Lateral diffusion of the lipids is on a significantly longer time scale because of restrictions at the bilayer/water interface, not because the interior of the bilayer is highly viscous.
Pastor
Richard W
RW
Laboratory of Biophysics, Center for Biologics Evaluation and Research, FDA, 1401 Rockville Pike, Rockville, Maryland 20852-1448, USA.
Venable
Richard M
RM
Feller
Scott E
SE
D003198:Computer Simulation; D004058:Diffusion; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D014867:Water / Q000378:metabolism
D008051:Lipid Bilayers; D014867:Water