Professional Interests
My major research interest is in theoretical modeling and computer simulation of lipid
bilayers and model biological membranes. I have used both the Configurational Bias Monte
Carlo Method (CBMC) and Molecular Dynamics (MD) to simulate lipid bilayers in water. The
simulations provide a wealth of detailed information about the atomic level properties of
water and lipid molecules which can be compared with experiment, and can be used to
help to construct better theoretical models. Current simulations being done by my group
and collaborators at the national Center for Supercomputing Applications (NCSA) at the
University of Illinois involve the properties of cholesterol in lipid membranes of
heterogeneous composition. In order to understand the structure and organization of
lipid "rafts" we have run simulations of up to 1600 lipid or cholesterol molecules, and
52,000 water molecules. The size of the simulation cell is about the same size as observed
nano-domains, or "rafts" which play important functional roles in membranes. Other
current work involves importing data from atomic level simulations to a coarse-grained
Langevin Dynamics model for lateral domain formation in lipid mixtures. This involves the
calculation of effective interaction parameters from the atomistic simulations, and
inputting them into a Self-Consistent Mean Field model for lipid bilayers. We have used
this approach to shed new light on the nature of the lateral organization of cholesterol in
lipid membranes and, in future work, will apply the method to lipid rafts.
Representative Publications
- Molecular-dynamics simulation of a ceramide bilayer, with S. A.Pandit, S. A J. Chem.
Phys., 124 :014708 (2006)
- Self-consistent Mean Field Model Based on Molecular Dynamics: Application to Lipid-
cholesterol Bilayers.'' , with G. Khelashvili and S. Pandit, J. Chem. Phys. 123, 034910 (2005)
- Sphingomyelin-Cholesterol domains in phospholipid membranes with S. Pandit, R. Jay Mashl,
S. W. Chiu, S. Vasudevan, and E. Jakobsson, Biophys J, J 87, 1092-1100 (2004)
- Simulation of early stages of domain nano-domain formation in mixed lipid bilayers of
sphingomyelin, cholesterol, and dioleylphosphatidylcholine”, with S. Pandit and E.
Jakobsson, Biophys J. 87, 3312 - 3322 (2004)
- Modeling the lipid component of membranes , Curr. Op. Struct. Biol. 12. 495-503 (2002)
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