2,567 research outputs found
Coarse-Grained Model for Phospholipid/Cholesterol Bilayer
We construct a coarse-grained (CG) model for dipalmitoylphosphatidylcholine
(DPPC)/cholesterol bilayers and apply it to large-scale simulation studies of
lipid membranes. Our CG model is a two-dimensional representation of the
membrane, where the individual lipid and sterol molecules are described by
point-like particles. The effective intermolecular interactions used in the
model are systematically derived from detailed atomic-scale molecular dynamics
simulations using the Inverse Monte Carlo technique, which guarantees that the
radial distribution properties of the CG model are consistent with those given
by the corresponding atomistic system. We find that the coarse-grained model
for the DPPC/cholesterol bilayer is substantially more efficient than atomistic
models, providing a speed-up of approximately eight orders of magnitude. The
results are in favor of formation of cholesterol-rich and cholesterol-poor
domains at intermediate cholesterol concentrations, in agreement with the
experimental phase diagram of the system. We also explore the limits of the
novel coarse-grained model, and discuss the general validity and applicability
of the present approach
Computational studies of biomembrane systems: Theoretical considerations, simulation models, and applications
This chapter summarizes several approaches combining theory, simulation and
experiment that aim for a better understanding of phenomena in lipid bilayers
and membrane protein systems, covering topics such as lipid rafts, membrane
mediated interactions, attraction between transmembrane proteins, and
aggregation in biomembranes leading to large superstructures such as the light
harvesting complex of green plants. After a general overview of theoretical
considerations and continuum theory of lipid membranes we introduce different
options for simulations of biomembrane systems, addressing questions such as:
What can be learned from generic models? When is it expedient to go beyond
them? And what are the merits and challenges for systematic coarse graining and
quasi-atomistic coarse grained models that ensure a certain chemical
specificity
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