Figure 5.

Docking results representing the prereactivation conformations of HI-6 (green) at the active sites of AChE and BuChE (gray) blocked by sarin and tabun (purple). The key amino acids involved in the interactions with the reactivator are marked with yellow sticks. The PAS region plays a huge role in ligand binding in both AChE and BuChE, despite the clear differences in the amino acids that build PAS of AChE and BuChE. Maintaining the BuChE prereactivation pose is dependent on the interaction with Tyr332 and Asp70. However, these interactions diminish during the formation of the transition state, in contrast to increasing interactions within the PAS AChE region.