Figure 2.

Snapshots of the binding process of an SMA copolymer to the surface of the membrane. (a) At the beginning (t = 0 ns), the polymer is in solution, taking a disordered conformation. (b) After 20 ns, the polymer adheres on the surface of the membrane through the hydrophobic terminal inserted between the lipid acyl tails. (c) At t = 400 ns, the polymer is fully absorbed to the lipid bilayer with sodium ions mediating the electrostatic interactions between the SMA carboxyl and the lipid headgroups. Styrene groups are shown in green, and carboxyl groups are shown in yellow. Lipids are shown with gray tails, orange phosphate, and blue choline groups. Lipids around the hydrophobic termini are highlighted in red in the left insert, with blue and orange beads representing the choline and phosphate groups, respectively. Purple beads represent Na⁺ ions, and brown beads represent Cl⁻ ions in the right insert. Some lipids in front of the polymer as well as water molecules were removed for clarity. Snapshots were obtained for a system with one copolymer. To see this figure in color, go online.