Reducing the number of particles for simulations of peptides on the edge of a nanodisc. (A) Top-down view; an entire nanodisc is cut through by two planes (dashed lines) yielding an approximately rectangular bilayer. (B) Top-down view; a rectangular bilayer models the nanodisc patch. The bilayer is surrounded by peptides and water and is periodic along the z axis. Periodic boxes are shown in lighter colors. (C) Side view of the bilayer in (B). Lipids, peptides, and water are shown as orange, blue, and gray circles, respectively. Simulation boxes are shown in red.