Acetylcholinesterase: structure and use as a model for specific cation—protein interactions

Abstract

Acetylcholinesterase is an α/β protein with an overall fold very similar to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The structure reveals, for the first time, a binding pocket for the neurotransmitter acetylcholine. The catalytic triad lies near the bottom of a deep and narrow gorge, lined with aromatic amino acids. The positive quaternary group in acetylcholine and other cholinergic ligands makes close contact with aromatic residues; thus, the π electrons of aromatic rings play a key role in cholinergic ligand binding.