Figure 8

Crystallographic water molecules on the protein surface, positions (a-d). A network of crystallographic water molecules in acetylcholinesterase is indicated by the "Y" shaped curve in yellow. These water molecules are centred on Arg220 which can be seen close to the "valley" of the "Y". The probe was moved over the surface placing it at the crystallographic water locations (four of which are indicated in the figure by a yellow circle), each of which gave the impression through the haptic device of being locally stable.