Figure 3.

Binding modes of the oxime reactivators in complexes with apo- (A and C) and VX-inhibited (B) hAChE. Shown are views of the active-site gorge with nonproductively bound RS194B at the choline-binding site of apo-AChE (A), nonproductively bound RS194B at the peripheral site of VX-hAChE (B), or bound LG-703 (C). For all panels, black dashed lines represent possible hydrogen-bonding interactions; the 2F_o − F_c electron density maps are shown as blue mesh and contoured at 1.5σ in A and 1.0σ levels in B and C; ligands are shown in stick models with carbon atoms in magenta for RS194B, yellow for LG-703, and purple for glycerol. Red spheres represent water molecules; catalytic Ser-203 is colored with cyan carbon atoms, and the rest of the enzyme residues are shown in green.