Crystal structure of soman-aged human butyryl cholinesterase in complex with the substrate analog butyrylthiocholine
[CHLE_HUMAN] Defects in BCHE are the cause of butyrylcholinesterase deficiency (BChE deficiency) [MIM:177400]. BChE deficiency is a metabolic disorder characterized by prolonged apnoea after the use of certain anesthetic drugs, including the muscle relaxants succinylcholine or mivacurium and other ester local anesthetics. The duration of the prolonged apnoea varies significantly depending on the extent of the enzyme deficiency. BChE deficiency is a multifactorial disorder. The hereditary condition is transmitted as an autosomal recessive trait.
Publication Abstract from PubMed
Cholinesterases are among the most efficient enzymes known. They are divided into two groups: acetylcholinesterase, involved in the hydrolysis of the neurotransmitter acetylcholine, and butyrylcholinesterase of unknown function. Several crystal structures of the former have shown that the active site is located at the bottom of a deep and narrow gorge, raising the question of how substrate and products enter and leave. Human butyrylcholinesterase (BChE) has attracted attention because it can hydrolyze toxic esters such as cocaine or scavenge organophosphorus pesticides and nerve agents. Here we report the crystal structures of several recombinant truncated human BChE complexes and conjugates and provide a description for mechanistically relevant non-productive substrate and product binding. As expected, the structure of BChE is similar to a previously published theoretical model of this enzyme and to the structure of Torpedo acetylcholinesterase. The main difference between the experimentally determined BChE structure and its model is found at the acyl binding pocket that is significantly bigger than expected. An electron density peak close to the catalytic Ser(198) has been modeled as bound butyrate.
Crystal structure of human butyrylcholinesterase and of its complexes with substrate and products.,Nicolet Y, Lockridge O, Masson P, Fontecilla-Camps JC, Nachon F J Biol Chem. 2003 Oct 17;278(42):41141-7. Epub 2003 Jul 17. PMID:12869558
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.