FIGURE 1.

Microscopic model of the α-hemolysin channel in its native environment, a lipid bilayer membrane. The channel is drawn as a molecular surface separating the protein from the membrane and water. The surface is colored according to the type of the exposed residues: red, blue, green, and white correspond to negatively charged, positively charged, polar, and nonpolar side chains, respectively. This surface is cut by the plane normal to the lipid bilayer, passing through the geometrical center of the protein. All but phosphorous atoms of the DPPC lipid bilayer are shown in green; the phosphorus atoms are shown as spheres. Water and ions are not shown. The model comprises 288,678 atoms.