Oxyanion hole acetylcholinesterase

Zhang Y, Kua J, McCammon JA (2002) Role of the catalytic triad and oxyanion hole in acetylcholinesterase catalysis an ab initio QM/MM study. J Am Chem Soc 124 10572—10577... 

All of these esterases appear to act by mechanisms closely related to those of proteases. Acetylcholinesterase contains an active site serine that reacts with organophosphorus compounds (Box 12-E) and is part of an Asp-His-Ser catalytic triad which lies in a deep "gorge" as well as an oxyanion hole.637 A surprise is the absence of an essential carboxylate group that might bind the positively charged trimethylammonium... 

Ordentlich, A., Barak, D., Kronman, C., Ariel, N. Segall, Y., Velan, B., Shafferman, A. (1998). Functional characteristics of the oxyanion hole in human acetylcholinesterase. J. Biol. Chem. 273 19509-17. 

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