Figure 2.

Octapeptin interaction with the bacterial outer membrane. A, distance of the center of mass of the octapeptin molecule from the center of the outer membrane. The polar headgroup region of the outer membrane is labeled by the two orange dashed lines. B and C show the structural snapshots of the penetration of octapeptin C4 and FADDI-115 in different regions of the outer membrane, respectively. The octapeptin molecule is shown as blue sticks, the lipid A–pEtN molecules are shown as teal lines, and the phospholipid molecules are shown as gray lines. The hydrogen bonds between the octapeptin molecule and the lipid A–pEtN molecules in the outer membrane are shown as purple dashed lines. D, the orientation of lipid A–pEtN molecule relative to the normal of the outer membrane.