Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 26: Posters: Membranes and Vesicles
BP 26.11: Poster
Donnerstag, 29. März 2012, 17:30–19:30, Poster A
Translocation of polymer chains through self-assembled lipid bilayers: A Monte Carlo study — •Marco Werner1,2 and Jens-Uwe Sommer1,2 — 1Leibniz-Institut für Polymerforschung Dresden, Germany — 2Technische Universität Dresden - Institute for Theoretical Physics
Recent experiments have shown that amphiphatic polymers may translocate through phospholipid bilayers using an ATP-independent mechanism [1]. This allows for interesting applications using flexible polymers as gene vectors, drug carriers or in cell imaging techniques. However, the mechanism of translocation is not known. We use a lattice-Monte Carlo model with explicit solvent to study self-assembled lipid bilayers interacting with single polymer chains, where all monomers of a polymer have an effective hydrophobic interaction. Under variation of the polymer hydrophobicity we observe an adsorption transition of the polymer at the surface of the bilayer. Close to the transition point the polymer induces significant perturbations of the orientational order of the lipids and the solvent permeability of the membrane is strongly increased locally. Furthermore, our simulation results indicate that for a critically adsorbed chain there is an additional free energy barrier to translocate through the bilayer’s core. For polymer chains with appropiately matched hydrophobicity the bilayer becomes energetically most transparent and we observe a maximum in the translocation frequency.
[1] T. Goda et al., Biomaterials 31(8): 2380-2387 (2010)