FIGURE 6.

Computational molecular modeling of VX-inhibited AChE showing the reversible Michaelis type complex (white sticks) and covalent pentacoordinate trigonal bipyramidal intermediate (yellow sticks) for interaction of initial lead oxime RS41A (A) and the lead oxime RS194B (B). Ten conformers of each oxime are shown in each of two interaction states. The phosphorus atom is colored purple. The solvent-accessible part of the hAChE Connolly surface is represented in orange, and the solvent-inaccessible part of the hAChE molecule is in dark gray. Pronounced overlapping similarity in global geometries of the reversible complex (white sticks) and trigonal bipyramidal intermediate (yellow sticks) was observed for RS194B oxime, but not with RS41A oxime.