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2wsl

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2wsl, resolution 2.00Å ()
Ligands: , , , , , , ,
Non-Standard Residues:
Activity: Cholinesterase, with EC number 3.1.1.8
Related: 2j4c, 1kcj, 2wik, 1p0p, 1xlu, 2wij, 1xlv, 1eho, 1p0m, 1xlw, 1ehq, 1p0q, 2wid, 2wil, 2wif, 1p0i, 2wig
Resources: FirstGlance, OCA, RCSB, PDBsum
Coordinates: save as pdb, mmCIF, xml


Contents

AGED FORM OF HUMAN BUTYRYLCHOLINESTERASE INHIBITED BY TABUN ANALOGUE TA4

Publication Abstract from PubMed

hBChE [human BChE (butyrylcholinesterase)] naturally scavenges OPs (organophosphates). This bioscavenger is currently in Clinical Phase I for pretreatment of OP intoxication. Phosphylated ChEs (cholinesterases) can undergo a spontaneous time-dependent process called 'aging' during which the conjugate is dealkylated, leading to creation of an enzyme that cannot be reactivated. hBChE inhibited by phosphoramidates such as tabun displays a peculiar resistance to oxime-mediated reactivation. We investigated the basis of oxime resistance of phosphoramidyl-BChE conjugates by determining the kinetics of inhibition, reactivation (obidoxime {1,1'-(oxybis-methylene) bis[4-(hydroxyimino) methyl] pyridinium dichloride}, TMB-4 [1,3-trimethylene-bis(4-hydroxyiminomethylpyridinium) dibromide], HLo 7 {1-[[[4-(aminocarbonyl) pyridinio]methoxy]methyl]-2,4-bis-[(hydroxyimino)methyl] pyridinium dimethanesulfonate)}, HI-6 {1-[[[4-(aminocarbonyl) pyridinio] methoxy] methyl]-2-[(hydroxyimino)methyl]pyridinium dichloride monohydrate} and aging, and the crystal structures of hBChE inhibited by different N-monoalkyl and N,N-dialkyl tabun analogues. The refined structures of aged hBChE conjugates show that aging proceeds through O-dealkylation of the P(R) enantiomer of N,N-diethyl and N-propyl analogues, with subsequent formation of a salt bridge preventing reactivation, similarly to a previous observation made on tabun-ChE conjugates. Interestingly, the N-methyl analogue projects its amino group towards the choline-binding pocket, so that aging proceeds through deamination. This orientation results from a preference of hBChE's acyl-binding pocket for larger than 2-atoms linear substituents. The correlation between the inhibitory potency and the N-monoalkyl chain length is related to increasingly optimized interactions with the acyl-binding pocket as shown by the X-ray structures. These kinetics and X-ray data lead to a structure-activity relationship that highlights steric and electronic effects of the amino substituent of phosphoramidate. This study provides the structural basis to design new oximes capable of reactivating phosphoramidyl-hBChE conjugates after intoxication, notably when hBChE is used as pretreatment, or to design BChE-based catalytic bioscavengers.

Structure-activity analysis of aging and reactivation of human butyrylcholinesterase inhibited by analogues of tabun., Carletti E, Aurbek N, Gillon E, Loiodice M, Nicolet Y, Fontecilla-Camps JC, Masson P, Thiermann H, Nachon F, Worek F, Biochem J. 2009 Jun 12;421(1):97-106. PMID:19368529

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Disease

[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.

Function

[CHLE_HUMAN] Esterase with broad substrate specificity. Contributes to the inactivation of the neurotransmitter acetylcholine. Can degrade neurotoxic organophosphate esters.[1][2]

About this Structure

2wsl is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA.

See Also

Reference

  • Carletti E, Aurbek N, Gillon E, Loiodice M, Nicolet Y, Fontecilla-Camps JC, Masson P, Thiermann H, Nachon F, Worek F. Structure-activity analysis of aging and reactivation of human butyrylcholinesterase inhibited by analogues of tabun. Biochem J. 2009 Jun 12;421(1):97-106. PMID:19368529 doi:10.1042/BJ20090091
  1. Chilukuri N, Duysen EG, Parikh K, diTargiani R, Doctor BP, Lockridge O, Saxena A. Adenovirus-transduced human butyrylcholinesterase in mouse blood functions as a bioscavenger of chemical warfare nerve agents. Mol Pharmacol. 2009 Sep;76(3):612-7. doi: 10.1124/mol.109.055665. Epub 2009 Jun, 19. PMID:19542320 doi:10.1124/mol.109.055665
  2. Amitay M, Shurki A. The structure of G117H mutant of butyrylcholinesterase: nerve agents scavenger. Proteins. 2009 Nov 1;77(2):370-7. doi: 10.1002/prot.22442. PMID:19452557 doi:10.1002/prot.22442

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