Computer Simulations of NMR Relaxation in Lipid Bilayers
October 13, Tue 2009
1:00 pm, MRB 100 Conference Room
Dr. Richard Pastor
Laboratory of Computational Biology, National Heart Lung and Blood Institute, NIH
The development of a simulation-based motional model for lipids in a bilayer is described. The model indicates that the several ns decay observed in both 13C and 31PT1 arises from restricted diffusion of the long axis of the lipid (sometimes termed "wobble"), in contrast to axial reorientation or collective motions. The faster (10-100 ps) dynamics of the chains arises from gauche-trans isomerization, and is virtually identical to isomerizations in liquid alkanes. These considerations lead to a detailed model for bilayer dynamics, and differs from the slab-like model proposed by the Saffman-Delbruck. Progress using coarse grained simulations to describe longer time-scale collective dynamics as well as self-assembly is also presented.