论文部分内容阅读
A new set of transferable Dissipative Particle Dynamics(DPD)force field for phospholipids,glycosphingolipids,and polypeptides will be presented in this talk.The coarse grained models of these molecules are constructed by mapping four heavy atoms and their attached hydrogens to one bead.The beads are divided into types distinguished by polarizability and hydrogen-bonding capacity.First we optimize the DPD force parameters given by Groot and Rabone [Biophys.J.81,715(2001)] to reproduce the structure and poration behavior of phospholipid bilayer membrane.Then we extend this force field to glycosphingolipids and polypeptides by considering the transferability of the bead types.The feasibility of this model is demonstrated by simulating the raft formation of ganglioside GM1 lipid in DOPC lipid bilayer and the binding of cholera toxin B subunits onto the raft.Spontaneous microdomain formation of GM1 is observed when the GM1/DOPC molar ratio is approaching or exceeding 3/100 which is comparable to experimental data.We also find that the multivalent binding of cholera toxin onto the membrane promotes the clustering of GM1 and lipid sorting.This method also enables us to simulate cell-killing mechanisms of antimicrobial peptides with various α-helical,β-sheet,and extended secondary structures.