Delacour H

References (10)

Title : Phenotype and genotype characteristics of 58 patients showing a prolonged effect of succinylcholine: a four-year experience - Millet_2021_Anaesth.Crit.Care.Pain.Med__100847
Author(s) : Millet C , Plaud B , Delacour H
Ref : Anaesth Crit Care Pain Med , :100847 , 2021
Abstract : INTRODUCTION: This study sought to describe the phenotype and genotype characteristics of patients referred to our laboratory to undergo further assessment due to a suspicion of a prolonged effect of suxamethonium attributed to BChE deficiency. METHODS: All patients referred to our laboratory from January 2016 to December 2019 due to the suspicion of a prolonged effect of suxamethonium were included in this study. The determination of BChE activity and genotyping using complete nucleotide sequencing of the entire complementary DNA-coding region with flanking intron-exon boundaries were completed. RESULTS: During this four-year period, 58 patients were referred to our laboratory for the investigation of prolonged neuromuscular block due to BChE deficiency. Among them, 52 showed a BChE deficiency related to BCHE gene mutations. The most commonly detected genotype was compound homozygous atypical variant (p.Asp98Gly)/homozygous Kalow variant (p.Ala569Thr) (p.[Asp98Gly;Ala567Thr];[p.Asp98Gly;Ala567Thr]). Further, we recorded four new BCHE variants which seems to be associated with prolonged post suxamethonium apnoea: p.(Trp205Cys), p.(Leu222His), p.(Glu469Gln), and p.(Lys276Ter). CONCLUSION: During a four-year period, among the 58 patients referred to our laboratory, we have found four new BCHE variants which seems to be associated with prolonged post suxamethonium apnoea (p.(Trp205Cys), p.(Leu22His), p.(Glu469Gln), and p.(Lys276Ter)).
ESTHER : Millet_2021_Anaesth.Crit.Care.Pain.Med__100847
PubMedSearch : Millet_2021_Anaesth.Crit.Care.Pain.Med__100847
PubMedID: 33774263

Title : Characterization of four BCHE mutations associated with prolonged effect of suxamethonium - Brazzolotto_2021_Pharmacogenomics.J_21_165
Author(s) : Brazzolotto X , Courcelle S , Sauvanet C , Guillon V , Igert A , Kononchik J , Nachon F , Ceppa F , Delacour H
Ref : Pharmacogenomics J , 21(2):165-173 : , 2021
Abstract : Butyrylcholinesterase (BChE) deficiency is characterized by prolonged apnea after the use of muscle relaxants (suxamethonium or mivacurium) in patients who have mutations in the BCHE gene. Here, we report the characterization of four BCHE mutations associated with prolonged effect of suxamethonium (amino acid numbering based on the matured enzyme): p.20delValPheGlyGlyThrValThr, p.Leu88His, p.Ile140del and p.Arg386Cys. Expression of recombinant BCHE mutants, kinetic analysis and molecular dynamics were undertaken to understand how these mutations induce BChE deficiency. Three of the mutations studied (p.20delValPheGlyGlyThrValThr, p.Ile140del and p.Arg386Cys) lead to a "silent" BChE phenotype. Recombinant BCHE expression studies for these mutants revealed BChE activity levels comparable to untransfected cells. Only the last one (hBChE-L88H) presented BChE activity in the transfected cell culture medium. This BChE mutant (p.Leu88His) is associated with a lower k(cat) value compare to the wild-type enzyme. Molecular dynamics simulations analyses suggest that a destabilization of a structure implicated in enzyme activity (-loop) can explain the modification of the kinetic parameter of the mutated protein.
ESTHER : Brazzolotto_2021_Pharmacogenomics.J_21_165
PubMedSearch : Brazzolotto_2021_Pharmacogenomics.J_21_165
PubMedID: 33024248

Title : Use of IFCC guidelines to verify acetylcholinesterase reference interval in adults determined with ChE check mobile testing system -
Author(s) : Lefrere B , Servonnet A , Ceppa F , Dorandeu F , Delacour H
Ref : Clinical Chemistry & Laboratory Medicine , 55 :e268 , 2017
PubMedID: 28467310

Title : The C5 Variant of the Butyrylcholinesterase Tetramer Includes a Noncovalently Bound 60 kDa Lamellipodin Fragment - Schopfer_2017_Molecules_22_
Author(s) : Schopfer LM , Delacour H , Masson P , Leroy J , Krejci E , Lockridge O
Ref : Molecules , 22 : , 2017
Abstract : Humans with the C5 genetic variant of butyrylcholinesterase (BChE) have 30-200% higher plasma BChE activity, low body weight, and shorter duration of action of the muscle relaxant succinylcholine. The C5 variant has an extra, slow-moving band of BChE activity on native polyacrylamide gel electrophoresis. This band is about 60 kDa larger than wild-type BChE. Umbilical cord BChE in 100% of newborn babies has a C5-like band. Our goal was to identify the unknown, 60 kDa protein in C5. Both wild-type and C5 BChE are under the genetic control of two independent loci, the BCHE gene on Chr 3q26.1 and the RAPH1 (lamellipodin) gene on Chr 2q33. Wild-type BChE tetramers are assembled around a 3 kDa polyproline peptide from lamellipodin. Western blot of boiled C5 and cord BChE showed a positive response with an antibody to the C-terminus of lamellipodin. The C-terminal exon of lamellipodin is about 60 kDa including an N-terminal polyproline. We propose that the unknown protein in C5 and cord BChE is encoded by the last exon of the RAPH1 gene. In 90% of the population, the 60 kDa fragment is shortened to 3 kDa during maturation to adulthood, leaving only 10% of adults with C5 BChE.
ESTHER : Schopfer_2017_Molecules_22_
PubMedSearch : Schopfer_2017_Molecules_22_
PubMedID: 28661448
Gene_locus related to this paper: human-BCHE

Title : Butyrylcholinesterase deficiency - Delacour_2016_Ann.Biol.Clin.(Paris)_74_279
Author(s) : Delacour H , Dedome E , Courcelle S , Hary B , Ceppa F
Ref : Ann Biol Clin (Paris) , 74 :279 , 2016
Abstract : Butyrylcholinesterase (EC 3.1.1.8; BChE) is a sister enzyme of acetylcholinesterase. Though BChE lacks obvious physiological functions, it is of toxicological and pharmacological importance in detoxifying or catabolising ester-containing drugs. Furthermore, individuals deficient in BChE appear asymptomatic, apart from a heightened sensitivity to the muscle relaxants suxamethonium and mivacurium, two BChE substrates used as myorelaxant. Although many acquired conditions may affect BChE activity, BChE deficiency is mainly due to mutations in the BCHE gene (OMIM 177400). Currently, more than 70 natural mutations have been documented in human BCHE. They have an adverse effect on BChE activity by affecting the catalytic functioning or the protein expression. However, the atypical variant (rs1799807) is the most frequently involved in prolonged apnea.
ESTHER : Delacour_2016_Ann.Biol.Clin.(Paris)_74_279
PubMedSearch : Delacour_2016_Ann.Biol.Clin.(Paris)_74_279
PubMedID: 27237801

Title : [Prolonged neuromuscular block in a patient with butyrylcholinesterase deficiency] - Mabboux_2016_Arch.Pediatr_23_497
Author(s) : Mabboux I , Hary B , Courcelle S , Ceppa F , Delacour H
Ref : Arch Pediatr , 23 :497 , 2016
Abstract : Succinylcholine is a neuromuscular block whose duration of action depends on rapid hydrolysis by butyrylcholinesterase (BChE). In patients with common BChE activities, succinylcholine duration of action is short (10min). BChE deficiency induces a slower hydrolysis of the drug and consequently prolonged neuromuscular block, leading to apnea. We report a case of prolonged neuromuscular block after administration of succinylcholine in a 14-year-old boy. Biological investigations revealed a marked BChE deficiency (1099U/L) related to the presence of three point mutations in the BCHE gene in a compound heterozygous state: p.Asp70Gly (rs1799807), p.Ala539Tyr (rs1803274), and p.Phe118Valfs*12 (rs398124632). The diagnosis of genetic BChE deficiency (OMIM 177400) was retained. This case is intended to present the pathophysiology of genetic BChE deficiency, its management, and the diagnostic strategy to be implemented.
ESTHER : Mabboux_2016_Arch.Pediatr_23_497
PubMedSearch : Mabboux_2016_Arch.Pediatr_23_497
PubMedID: 27017361

Title : Human butyrylcholinesterase polymorphism: Molecular modeling - Lushchekina_2015_Int.J.Risk.Saf.Med_27 Suppl 1_S80
Author(s) : Lushchekina SV , Delacour H , Lockridge O , Masson P
Ref : Int J Risk Saf Med , 27 Suppl 1 :S80 , 2015
Abstract : BACKGROUND: Prolonged apnoea following injection of ester-containing myoralaxants was first described in 1953. Because a large part of administered succinylcholine is shortly hydrolyzed by plasma butyrylcholinesterase (BChE) under normal conditions, prolonged apnoea was attributed to deficiency in BChE. It was found that BChE deficiency was due to genetic variations. Human BChE gene shows a large polyallelism. About 75 natural mutations of the BCHE gene have been documented so far [1]. Most of them cause alteration in BChE activity through point mutation effect on catalytic activity. Frame shifts and stop codons may also affect expression, or cause truncations in the sequence. OBJECTIVE: Recently, two novel BChE "silent" variants, Val204Asp [2] and Ala34Val [3], causing prolonged neuromuscular block after administration of mivacurium, were discovered. Mutations were genetically and kinetically characterized. The aim of the current study was to understand how these mutations determine "silent" phenotype.
METHODS: Molecular dynamics studies were carried out with NAMD 2.9 software at the Lomonosov supercomputer. Charmm 36 force field was used, periodical boundary conditions, 1 atm pressure, 298 K. 100 ns molecular dynamics runs were performed for the wild-type BChE and its mutants Val204Asp and Ala34Val.
RESULTS: Unlike wild-type BChE, which retained its operative catalytic triad through the whole MD simulation, the catalytic triad of mutants was disrupted, making chemical step impossible. Val204Asp mutation leads to reorganization of hydrogen bonding network around the catalytic triad, which in turn increases the distance between catalytic residue main chains. Mutation Ala34Val, located on the protein surface, leads to increased fluctuations in the Omega-loop and subsequent disruption of the gorge structure, including disruption of the catalytic triad and formation of new hydrogen bonds involving catalytic center residues.
CONCLUSIONS: Comparative study of the "silent" Ala328Asp mutant and the catalytically active mutant Ala328Cys shows that MD approach can discriminate between the differential effects of point mutations at a same position.
ESTHER : Lushchekina_2015_Int.J.Risk.Saf.Med_27 Suppl 1_S80
PubMedSearch : Lushchekina_2015_Int.J.Risk.Saf.Med_27 Suppl 1_S80
PubMedID: 26639724

Title : Characterization of a Novel BCHE Silent Allele: Point Mutation (p.Val204Asp) Causes Loss of Activity and Prolonged Apnea with Suxamethonium - Delacour_2014_PLoS.One_9_e101552
Author(s) : Delacour H , Lushchekina SV , Mabboux I , Bousquet A , Ceppa F , Schopfer LM , Lockridge O , Masson P
Ref : PLoS ONE , 9 :e101552 , 2014
Abstract : Butyrylcholinesterase deficiency is characterized by prolonged apnea after the use of muscle relaxants (suxamethonium or mivacurium) in patients who have mutations in the BCHE gene. Here, we report a case of prolonged neuromuscular block after administration of suxamethonium leading to the discovery of a novel BCHE variant (c.695T>A, p.Val204Asp). Inhibition studies, kinetic analysis and molecular dynamics were undertaken to understand how this mutation disrupts the catalytic triad and determines a "silent" phenotype. Low activity of patient plasma butyrylcholinesterase with butyrylthiocholine (BTC) and benzoylcholine, and values of dibucaine and fluoride numbers fit with heterozygous atypical silent genotype. Electrophoretic analysis of plasma BChE of the proband and his mother showed that patient has a reduced amount of tetrameric enzyme in plasma and that minor fast-moving BChE components: monomer, dimer, and monomer-albumin conjugate are missing. Kinetic analysis showed that the p.Val204Asp/p.Asp70Gly-p.Ala539Thr BChE displays a pure Michaelian behavior with BTC as the substrate. Both catalytic parameters Km = 265 microM for BTC, two times higher than that of the atypical enzyme, and a low Vmax are consistent with the absence of activity against suxamethonium. Molecular dynamic (MD) simulations showed that the overall effect of the mutation p.Val204Asp is disruption of hydrogen bonding between Gln223 and Glu441, leading Ser198 and His438 to move away from each other with subsequent disruption of the catalytic triad functionality regardless of the type of substrate. MD also showed that the enzyme volume is increased, suggesting a pre-denaturation state. This fits with the reduced concentration of p.Ala204Asp/p.Asp70Gly-p.Ala539Thr tetrameric enzyme in the plasma and non-detectable fast moving-bands on electrophoresis gels.
ESTHER : Delacour_2014_PLoS.One_9_e101552
PubMedSearch : Delacour_2014_PLoS.One_9_e101552
PubMedID: 25054547

Title : Characterization of a novel butyrylcholinesterase point mutation (p.Ala34Val), silent with mivacurium - Delacour_2014_Biochem.Pharmacol_92_476
Author(s) : Delacour H , Lushchekina SV , Mabboux I , Ceppa F , Masson P , Schopfer LM , Lockridge O
Ref : Biochemical Pharmacology , 92 :476 , 2014
Abstract : Butyrylcholinesterase deficiency is characterized by prolonged apnea after the use of muscle relaxants (suxamethonium or mivarcurium) in patients who have mutations in the BCHE gene. Here, we report a case of prolonged neuromuscular block after administration of mivacurium leading to the discovery of a novel BCHE variant (c.185C>T, p.Ala34Val). Inhibition studies, kinetic analysis and molecular dynamics were undertaken to understand how this mutation remote from the active center determines the "silent" phenotype. Low activity of patient plasma butyrylcholinesterase with butyrylthiocholine (BTC) and benzoylcholine, and values of dibucaine and fluoride numbers fit with a heterozygous enzyme of type atypical/silent. Kinetic analysis with succinyldithiocholine (SCdTC) as the substrate showed that Ala34Val BChE was inactive against this substrate. However, with BTC, the mutant enzyme was active, displaying an unexpected activation by excess substrate. Competitive inhibition of BTC by mivacurium gave a Ki=1.35mM consistent with the lack of activity with the related substrate SCdTC, and with the clinical data. Molecular dynamic simulations revealed the mechanism by which mutation Ala34Val determines the silent phenotype: a chain of intramolecular events leads to disruption of the catalytic triad, so that His438 no longer interacts with Ser198, but instead forms hydrogen bonds either with residues Glu197 and Trp82, or peripheral site residue Tyr332. However, at high BTC concentration, initial binding of substrate to the peripheral site triggers restoration of a functional catalytic triad, and activity with BTC.
ESTHER : Delacour_2014_Biochem.Pharmacol_92_476
PubMedSearch : Delacour_2014_Biochem.Pharmacol_92_476
PubMedID: 25264279

Title : Rapid detection of BCHE atypical variant (p.Asp70Gly) by high resolution melting curve analysis - Mabboux_2014_Ann.Biol.Clin.(Paris)_72_543
Author(s) : Mabboux I , Dos Santos M , Courcelle S , Hary B , Ceppa F , Delacour H
Ref : Ann Biol Clin (Paris) , 72 :543 , 2014
Abstract : Butyrylcholinesterase (BChE) deficiency is characterized by prolonged apnea after the use of muscle relaxants (suxamethonium or mivacurium). Although many acquired conditions may affect BChE activity, BChE deficiency is mainly due to mutations in the BCHE gene (MIM 177400). Though close to 70 natural mutations have been documented in human BCHE, the atypical variant (rs1799807) is the most frequently involved in prolonged apnea. We describe an HRM method for the detection of this variant. Thirty-four patients with known genotype [5 wild-type (U/U), 12 heterozygous (U/A), 17 homozygous (A/A) - A: atypical allele of BCHE, U: usual allele of BCHE -] were screened with the HRM analysis. Within and between-run precision were also evaluated. In silico prediction of HRM curves was performed in order to evaluate the potential impact of the other SNPs described within the PCR product on the HRM diagnostic accuracy. HRM analysis for the BCHE atypical variant genotyping is a simple, rapid, sensitive and low cost method.
ESTHER : Mabboux_2014_Ann.Biol.Clin.(Paris)_72_543
PubMedSearch : Mabboux_2014_Ann.Biol.Clin.(Paris)_72_543
PubMedID: 25336127