Biophysical Society Thematic Meeting| Padova 2019

Quantitative Aspects of Membrane Fusion and Fission

Tuesday Speaker Abstracts

PARAMETRIC PARTICLE-BASED MODEL FOR LARGE-SCALE SIMULATIONS OF MEMBRANE DYNAMICS Mohsen Sadeghi 1 ; Frank Noé 1 ; 1 Freie Universität Berlin, Department of Mathematics and Computer Science, Berlin, Berlin, Germany We have developed a computationally efficient coarse-grained membrane model, to be used in concert with particle-based reaction-diffusion simulations [1]. The model is purely based on nearest-neighbor interactions between particles that each represent a coarse patch of a lipid monolayer. Interaction potentials are parameterized so as to reproduce the local membrane mechanics, whereas the in-plane fluidity is implemented with Monte Carlo bond-flipping moves. To tackle different kinetics of in-plane and out-of-plane degrees of freedom, and to achieve a realistic model of membranes suspended in solvents, we have also developed an anisotropic stochastic dynamics scheme, based on exact solutions of Stokes equations. While drastically increasing the available sampling range, this approach also allows for modeling hydrodynamic interactions mediated by the solvent. Different aspects of the model are put to the test through studying equilibrium thermal undulations, isothermal area compressibility, diffusion and viscosity, dispersion relations, and interaction of the bilayer membrane with curvature-inducing agents. We expect this model to be of high practical usability in the context of ultra coarse- grained interacting particle reaction-dynamics (iPRD) simulations of cellular dynamics [2]. [1] M. Sadeghi, T. R. Weikl, F. Noé, J. Chem. Phys. 148 044901 (2018).[2] M. Hoffmann, C. Fröhner, F. Noé, bioRxiv doi: 10.1101/374942 (2018).

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