DYNAMICS OF MULTICOMPONENT LIPID MEMBRANES
Dr. Brian Camley
Department of Physics and Center for Theoretical Biological Physics
UCSD
ABSTRACT
Biological membranes are composed of (among other things) hundreds of
different lipids, which are believed to segregate into fluid rafts,
which may be relevant to processes like virus assembly. I'll talk
about the spherical cow version of cells, synthetic membranes with
three
components (saturated and unsaturated lipids and cholesterol), which
also segregate into two fluid phases. Membranes are also particularly
interesting from a physical standpoint because they have both two- and
three-dimensional hydrodynamic behavior ("quasi-2D"), with many
strange features,
such as diffusion coefficients of membrane rafts being effectively
independent of their size. These quirks are characteristic of many
interfacial fluids, and also appear in thin layers of liquid crystals
and protein films at the air-water interface. I'll show some
continuum stochastic simulations of
membrane domains and phase separation, discuss new ways of measuring
membrane viscosity, and suggest why some well-known
dynamical scaling laws can change their exponents or even break down
for phase separation in membranes. If there's time, I will also
discuss
how the dynamics of protein diffusion can be altered by coupling to
the lipid membrane.
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