New Photolabile Inhibitors of Cholinesterases Designed for Rapid Photochemical Release of Choline

Abstract

The catalytic mechanism of rapid hydrolysis of acetylcholine by acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) has gained new interest since the description of the 3D-structure of AChE (Sussman et al., 1991) and the deduced model-structure of BuChE (Harel et al., 1992). In particular, it is still unclear how choline is cleared from the active site which is located at the bottom of a deep, narrow “aromatic gorge”. The development of the time-resolved crystallography (Cruickshank et al., 1992) has made it possible to analyze the catalytic process of an enzyme at the atomic level. In order to study the dynamic process of choline escape by such method, three photolabile choline precursors (Figure) were synthesized and tested for their potential use in time-resolved crystallographic studies on cholinesterases.