Butyrylcholinesterase
Butyrylcholinesterase (BChE) is an enzyme widely distributed throughout the body in humans, but particularly prevalent in serum, where it occurs as a tetramer of catalytic subunits. It is distinguished from the homologous enzyme, acetylcholinesterase, by its ability to hydrolyze the non-natural substrate butyrylcholine as well as the neurotransmitter, acetylcholine. Its biological role remains obscure, but mutations in the human BCHE gene result in prolonged post-surgical apnea due to the inability of the mutant BChEs to hydrolyse the local anaesthetic, succinylcholine. BChE finds medical use as a bioscavenger for overcoming organophosphate (OP) nerve agent and insecticide intoxication by interacting rapidly with the toxic agents. Crystal structures of both the native enzyme and of its conjugates with nerve agents are available. The image at the right correspond to one representative BChE, i.e. the crystal structure of recombinant full length human butyrylcholinesterase (2pm8).
3D structures of BChE3D structures of BChE
Update November 2011
hBChE - Apo humanhBChE - Apo human
2pm8, 1p0i - hBChE - human
2xmb – hBChE (mutant)+SO4
2xmc - hBChE (mutant)+F
4AQD - hBChE (fully glycosylated)
BChE+OP irreversible inhibitors, including nerve agents and insecticidesBChE+OP irreversible inhibitors, including nerve agents and insecticides
3djy, 3dkk - hBChE+tabun
2wid, 2wif - hBChE+Tabun analogue TA1
2wsl, 2wig – hBChE+Tabun analogue TA4
2wil, 2wij - hBChE+Tabun analogue TA5
2wik - hBChE+Tabun analogue TA6
1xlw - hBChE+echothiophate
1xmd, 2xmd – hBChE (mutant)+echothiophate
1p0q - hBChE+soman
1xlu - hBChE+Di-Isopropyl-Phosphoro-Fluoridate (DFP)
2xmg - hBChE (mutant)+VX
1xlv – hBChE+ethyl dihydrogen phosphate
2y1k - hBChE (mutant) + CBDP
4bop - hBChE (Aged) + methyl 2-(pentafluorobenzyloxyimino)pyridinium
BChE+inhibitor binding at surface of the protein (far from the active site)BChE+inhibitor binding at surface of the protein (far from the active site)
2j4c – hBChE+ HgCl2
BChE + substrate analogues mimicking the binding of the substrate butyrylcholineBChE + substrate analogues mimicking the binding of the substrate butyrylcholine
1p0m - hBChE+choline
1p0p - hBChE+butyrylthiocholine
3o9m - hBChE + benzoic acid
1eho, 1ehq, 1kcj – hBChE + cocaine - model
Additional ResourcesAdditional Resources
For additional information, see: Alzheimer's Disease