| dc.description.abstract | The fundamental structure of all biological membranes is the lipid bilayer. At-
tributed to the multifaceted features of lipids and its dynamical interaction with
other membrane-integrated molecules, the lipid bilayer is involved in a variety of
physiological phenomena such as transmembrane transportation, cellular signalling
transduction, energy storage, etc. Due to the nanoscale but high complexity of
the lipid bilayer system, experimental investigation into many important processes
at the molecular level is still challenging. Molecular dynamics (MD) simulation
has been emerging as a powerful tool to study the lipid membrane at the nanoscale.
Utilizing atomistic MD, we have quantitatively investigated the effect of lamellar and
nonlamellar lipid composition changes on a series of important bilayer properties,
and how membranes behave when exposed to a high-pressure environment. A series
of membrane properties such as lateral pressure and dipole potential pro les are
quanti ed. Results suggest the hypothesis that compositional changes, involving
both lipid heads and tails, modulate crucial mechanical and electrical features of
the lipid bilayer, so that a range of biological phenomena, such as the permeation
through the membrane and conformational equilibria of membrane proteins, may
be regulated. Furthermore, water also plays an essential role in the biomembrane
system. To balance accuracy and efficiency in simulations, a coarse-grained ELBA
water model was developed. Here, the ELBA water model is stress tested in terms
of temperature- and pressure-related properties, as well as hydrating properties.
Results show that the accuracy of the ELBA model is almost as good as conventional
atomistic water models, while the computational efficiency is increased substantially. | en_US |
