Molecular dynamics simulations of membrane deformation induced by amphiphilic helices of Epsin,Sar1p,and Arf1

The N-terminal amphiphilic helices of proteins Epsin,Sarlp,and Arfl play a critical role in initiating membrane deformation.The interactions of these amphiphilic helices with the lipid membranes are investigated in this study by combining the all-atom and coarse-grained simulations.In the all-atom simulations,the amphiphilic helices of Epsin and Sarlp are found to have a shallower insertion depth into the membrane than the amphiphilic helix of Arfl,but remarkably,the amphiphilic helices of Epsin and Sat lp induce higher asymmetry in the lipid packing between the two monolayers of the membrane.The insertion depth of amphiphilic helix into the membrane is determined not only by the overall hydrophobicity but also by the specific distributions of polar and non-polar residues along the helix.To directly compare their ability to deform the membrane,the coarse-grained simulations are performed to investigate the membrane deformation under the insertion of multiple helices.