Acetylcholinesterase and Its Inhibition

Abstract

Acetylcholinesterase (AChE) (3.1.1.7) belongs to the very large group of enzymes called hydrolases, defined as enzymes which split substrates by the introduction of the elements of water. The hydrolases which split acetylcholine are called cholinesterases; they catalyze the reaction

$$ \begin{array}{*{20}{c}} {C{{H}_{3}}COOC{{H}_{2}}C{{H}_{2}}\mathop{N}\limits^{ + } {{{(C{{H}_{3}})}}_{3}}\mathop{ \to }\limits^{{{{H}_{2}}O}} C{{H}_{3}}CO{{O}^{ - }} + {{H}^{ + }} + HOC{{H}_{2}}C{{H}_{2}}\mathop{N}\limits^{ + } {{{(C{{H}_{3}})}}_{3}}} \\ {{\text{acetylcholine acetate choline}}} \\ \end{array} $$

((1))

The reaction is reversible, but under usual conditions it lies far to the right.