Our Co-Founder, Dr. Wang, gave an academic report at Dalian Institute of Chemical Physics, Chinese Academy of Sciences.

Title: Multi-scale solvent-free coarse-grained modeling of lipid bilayer membranes: from top-down to systematic scheme

Abstract: This talk will focus on the implicit solvent coarse-grained (CG) modeling of lipid bilayer membranes. Starting from an introduction on my three-bead solvent-free CG membrane model developed in the top-down scheme a few years ago, I explain the importance of CG modeling and what we can study with even such a simple CG model. Afterwards, I will spend more time on my recent work of a systematic solvent-free CG modeling. The systematic solvent-free CG model reserves chemical speci_city and quantitative accuracy. At the same time, the use of implicit solvent enables membrane simulations on large length- and time-scales at moderate computational expense. The bonded and nonbonded interactions together with the e_ective cohesion mimicking the hydrophobic e_ect were systematically tuned by matching the structural and mechanical properties from experiments and all-atom bilayer simulations, such as saturated area per lipid, radial distribution functions, density and pressure pro_le across the bilayer, P2 order, etc. The CG lipid model is shown to self-assemble into a bilayer starting from a random dispersion. Its bending and stretching modulus and line tension are semi-quantitatively consistent with experiments and all-atom simulations. Simulations of POPC, DOPC and DPPC demonstrated a good parameter transferability of the CG force _led from one lipid to another, and from one phase to another. The e_ects of a reduced molecular friction together with a more e_cient integration combine to an overall speedup of three to four orders of magnitude compared to all-atom bilayer simulations. The systematic CG lipid model is especially useful for studies of large-scale phenomena in membranes which nevertheless require a fair description of chemical speci_city. It would be valuable to apply the systematic CG modeling methodology to other materials and systems.

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