Mar 23 – 24, 2009
KTH - Royal Institute of Technology
Europe/Stockholm timezone

Partitioning between water and lipid bilayers

Mar 24, 2009, 11:15 AM
45m
F3 (KTH - Royal Institute of Technology)

F3

KTH - Royal Institute of Technology

Lindstedtsväg 26

Speaker

Prof. Peter Tieleman (University of Calgary, Canada)

Description

The thermodynamics of interactions between the lipid bilayer and other molecules determines to a large extend the transport rate of these molecules across the bilayer as well as the nature of the process involved in partitioning. In the past few years we have studied these interactions for a range of organic molecules, for lipids, cholesterol, fullerenes, and models of carbon nanotubes. The large gradients in density, order, and hydrophobicity in a bilayer make partitioning a highly non-trivial process that is difficult to predict. Insertion of polar or charged molecules in particular involves significant changes in the bilayer structure, which dominate the cost of partitioning. An extreme example of this is the partitioning of multiple arginine side chains into the bilayer, which is a highly non-additive process with most of the energetic cost determined by the formation of an initial water defect. Similar observations are made for transport of lipids. Coarse-grained simulations of fullerene show little membrane perturbation, but investigations of nanotubes show significant and non-trivial effects that depend on the orientation of the nanotube. The systematic series of calculations from our lab may be useful in understanding the transport of functionalized nanoparticles through lipid membranes as one of the determinants of bioavailability and toxicity. References: W.F.D. Bennett, J.L. MacCallum, D.P. Tieleman. 2009. Thermodynamic analysis of the effect of cholesterol on dipalmitoylphosphatidylcholine lipid membranes., J. Am. Chem. Soc. 131, pp.1972-1978. J. Wong-Ekkabut, S. Baoukina, W. Triampo, I-M. Tang, D.P. Tieleman, L. Monticelli. 2008. Computer simulation study of fullerene translocation through lipid membranes, Nature Nanotechnology 3, pp. 363 – 368 J.L. MacCallum, D.P. Tieleman. 2008. Interactions between small molecules and lipid bilayers, Curr. Top. Memb. 60, pp. 227-256 J.L. MacCallum, W.F. D. Bennett, D. P. Tieleman. 2008. Distribution of Amino Acids in a Lipid Bilayer from Computer Simulations, Biophys. J. 94, pp. 3393-3404

Primary author

Prof. Peter Tieleman (University of Calgary, Canada)

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