Fig. 4.

The NT and NT* tube are approximately perpendicular to the bilayer plane throughout the simulation as discussed in the text. The oscillations in the positioning of the NT tube (Upper), however, allow for lipid tails to penetrate the lumen of the tube and occlude the pore. Simulations with longer purely hydrophobic tubes resulted in tubes with larger tilt angles and pore occlusion. The oscillations are reduced by the addition of hydrophilic caps to the NT* tube (Lower). This tube can conduct water sites across the membrane. The embedded graphs represent normalized histograms of the tilt angles collected from the simulations.