Electrostatics of AChE–Fas2. (a) Surface potential map of AChE and Fas2 at separation of 14 Å. The two green arrows indicated as F and M show the force (0.10, −0.03, −0.69) and torque (−0.35, −1.03, −2.8), respectively, which are scaled for visualization. (b) The interaction energy profiles as functions of separations along a predefined unbinding direction. U, total electrostatic interaction; U0, electrostatic interaction energy without consideration of the ligand polarization and desolvation effects as the typical treatment in UHBD; Ud-AChE and Ud-Fas2, electrostatic desolvation energies due to AChE and Fas2 cavities, respectively; Unonpolar, nonpolar contribution from a simple surface term. (c) The x, y, z components of forces, and torques acting on Fas2 as functions of the separation distances along a predefined unbinding direction.