Figure 1.

(a) Initial structures of explicit DMPC membrane systems with rotation angles of 20° (left) and 0° (right). Hydrophobic groups are highlighted in yellow and hydrophilic groups in red. Nitrogen and phosphorus atoms of the DMPC headgroups are illustrated as blue and tan spheres, respectively, while lipid tails are cyan and water molecules are gray. (b) Illustration of the coordinate system used to describe hairpin motions.