Coarse-graining of cholesterol containing lipid bilayers

Monday, November 3, 2008 - 10:30am - 11:15am
EE/CS 3-180
Mikko Karttunen (University of Western Ontario)
I will discuss multiscale modeling of biological
membranes. The approach is based on the so-called
Inverse Monte Carlo (IMC) method and the Henderson theorem.
The specific examples [1] will include single and multicomponent
bilayers using different levels of coarse-graining, and the
improvent of accuracy of the coarse-grained models by
using a thermodynamic constraint. The motivation for
including a constraint is that the basic IMC does not
yield physically meaningful area compressibility or
surface tension in coarse-grained bilayers.
The results using cholesterol containing systems show formation of
denser transient regions, resembling lipid rafts, which is in accord with
observations from microscopic models. Finally, I will
discuss some of the advantages and disadvantages of
this approach.


[1] T. Murtola, E. Falck, M. Patra, M. Karttunen, I. Vattulainen,
J. Chem. Phys. 121:9156-9165