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Onder S, Schopfer LM, Jiang W, Tacal O, Lockridge O. Butyrylcholinesterase in SH-SY5Y human neuroblastoma cells. Neurotoxicology 2022; 90:1-9. [PMID: 35189179 PMCID: PMC9124689 DOI: 10.1016/j.neuro.2022.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 10/19/2022]
Abstract
Cultured SH-SY5Y human neuroblastoma cells are used in neurotoxicity assays. These cells express markers of the cholinergic and dopaminergic systems. Acetylcholinesterase (AChE) activity has been reported in these cells. Neurotoxic organophosphate compounds that inhibit AChE, also inhibit butyrylcholinesterase (BChE). We confirmed the presence of AChE in the cell lysate by activity assays, Western blot, and liquid chromatography-tandem mass spectrometry (LC-MS/MS) of immunopurified AChE. A nondenaturing gel stained for AChE activity identified the catalytically active AChE in SH-SY5Y cells as the unstable monomer. We also identified immature BChE in the cell lysate. The concentration of active BChE protein was similar to that of active AChE protein. The rate of substrate hydrolysis by AChE was 10-fold higher than substrate hydrolysis by BChE. The higher rate was due to the 10-fold higher specific activity of AChE over BChE (5000 units/mg for AChE; 500 units/mg for BChE). Neither cholinesterase was secreted. Tryptic peptides of immunopurified AChE and BChE were identified by LC-MS/MS on an Orbitrap Lumos Fusion mass spectrometer. The unfolded protein chaperone, binding immunoglobulin protein BiP/GRP78, was identified in the mass spectral data from all cholinesterase samples, suggesting that BiP was co-extracted with cholinesterase. This suggests that the cytoplasmic cholinesterases are immature forms of AChE and BChE that bind to BiP. It was concluded that SH-SY5Y cells express active AChE and active BChE, but the proteins do not mature to glycosylated tetramers.
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Monoclonal antibodies to fetal bovine serum acetylcholinesterase distinguish between acetylcholinesterases from ruminant and non-ruminant species. Chem Biol Interact 2020; 330:109225. [PMID: 32795450 DOI: 10.1016/j.cbi.2020.109225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 11/24/2022]
Abstract
Two types of cholinesterases (ChEs) are present in mammalian blood and tissues: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). While AChE regulates neurotransmission by hydrolyzing acetylcholine at the postsynaptic membranes and neuromuscular junctions, BChE in plasma has been suggested to be involved in detoxifying toxic compounds. This study was undertaken to establish the identity of circulating ChE activity in plasmas from domestic animals (bovine, ovine, caprine, porcine and equine) by assessing sensitivity to AChE-specific inhibitors (BW284c51 and edrophonium) and BChE-specific inhibitors (dibucaine, ethopropazine and Iso-OMPA) as well as binding to anti-FBS AChE monoclonal antibodies (MAbs). Based on the inhibition of ChE activity by ChE-specific inhibitors, it was determined that bovine, ovine and caprine plasma predominantly contain AChE, while porcine and equine plasma contain BChE. Three of the anti-FBS AChE MAbs, 4E5, 5E8 and 6H9, inhibited 85-98% of enzyme activity in bovine, ovine and caprine plasma, confirming that the esterase in these plasmas was AChE. These MAbs did not bind to purified recombinant human or mouse AChE, demonstrating that these MAbs were specific for AChEs from ruminant species. These MAbs did not inhibit the activity of purified human BChE, or ChE activity in porcine and equine plasma, confirming that the ChE in these plasmas was BChE. Taken together, these results demonstrate that anti-FBS AChE MAbs can serve as useful tools for distinguishing between AChEs from ruminant and non-ruminant species and BChEs.
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Hou S, Zhang Y, Zhu Y, Zhang C, Kong Y, Chen X, Chen R, Yin X, Xie T, Chen X. Evaluation of the cholinesterase activity of a potential therapeutic cocaine esterase for cocaine overdose. Drug Alcohol Depend 2019; 202:168-171. [PMID: 31352306 DOI: 10.1016/j.drugalcdep.2019.04.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 04/06/2019] [Accepted: 04/30/2019] [Indexed: 01/09/2023]
Abstract
BACKGROUND Cocaine is a commonly abused drug and there is no approved medication specifically to treat its addiction or overdose. Bacterial cocaine esterase (CocE)-derived RBP-8000 is currently under clinical development for cocaine overdose treatment. It is proven to be effective for human use to accelerate cocaine metabolism into physiologically inactive products. Besides cocaine, RBP-8000 may hydrolyze the neurotransmitter acetylcholine (ACh), however, no study has reported its cholinesterase activity. The present study aims to examine RBP-8000's cholinesterase activity and substrate selectivity to address the potential concern that this enzyme therapy might produce cholinergic side-effects. METHODS Both computational modeling and experimental kinetic analysis were carried out to characterize the potential cholinesterase activity of RBP-8000. Substrates interacting with RBP-8000 were modeled for their enzyme-substrate binding complexes. In vitro enzymatic kinetic parameters were measured using Ellman's colorimetric assay and analyzed by Michaelis-Menten kinetics. RESULTS It is the first demonstration that RBP-8000 catalyzes the hydrolysis of acetylthiocholine (ATC). However, its catalytic efficiency (kcat/KM) against ATC is 1000-fold and 5000-fold lower than it against cocaine at 25 °C and 37 °C, respectively, suggesting RBP-8000 has the desired substrate selectivity for cocaine over ACh. CONCLUSION Given the fact that clinically relevant dose of RBP-8000 displays insignificant cholinesterase activity relative to endogenous cholinesterases in human, administration of RBP-8000 is unlikely to produce any significant cholinergic side-effects. This study provides supplemental evidences in support of further development of RBP-8000 towards a clinically used pharmacotherapy for cocaine overdose.
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Affiliation(s)
- Shurong Hou
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Yun Zhang
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Yao Zhu
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Chao Zhang
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Yichao Kong
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Xiaoling Chen
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Rong Chen
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Xiaopu Yin
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China
| | - Tian Xie
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China.
| | - Xiabin Chen
- Key Laboratory of Elemene Class Anti-Cancer Chinese Medicine of Zhejiang Province, Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province, Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine, Hangzhou Normal University. 2318 Yuhangtang Rd, Hangzhou, Zhejiang 311121, China.
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Seto Y, Kanamori-Kataoka M, Komano A, Nagoya T, Sasano R, Matsuo S. Gas chromatography-mass spectrometry with spiral large-volume injection for determination of fluoridated phosphonates produced by fluoride-mediated regeneration of nerve agent adduct in human serum. J Chromatogr A 2018; 1583:108-116. [PMID: 30470454 DOI: 10.1016/j.chroma.2018.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/27/2018] [Accepted: 11/05/2018] [Indexed: 11/18/2022]
Abstract
A sensitive method for determination of fluoridated phosphonates produced by fluoride-mediated regeneration of nerve agent adduct in human serum was developed using gas chromatography-mass spectrometry (GCMS) with large-volume injection. The GC injection was administered using stomach-type spiral injector (LVI, AiSTI SCIENCE) enabling introduction of only target compounds from 50 μL ethyl acetate extract after purging the solvent. For GCMS analysis of sarin (GB), 670 times higher sensitivity, based on limit of detection (LOD, S/N = 3, on extracted ion chromatogram (EIC) at m/z 99), was achieved using this injection (50 μL) compared to that achieved using 1 μL split injection (ratio 20:1). Ethyl (EtGB), isopropyl (GB), n-propyl (nPrGB), isobutyl (iBuGB), pinacolyl (GD), cyclohexyl (GF) methylphosphonofluoridates, and O-ethyl N, N-dimethylphosphoramidofluoridate (GAF) were detected with low LOD (15-75 pg/mL) and sharp peak shapes (high practical plate number (defined as 5.54 x (tR/Wh)2, where tR is the retention time and Wh is the bandwidth at half-height): 1100000-2400000) in GCMS using a polar separation column, electron ionization, and quadruple mass analyzer. During the analysis of fluoridated phosphonate-spiked ethyl acetate extract of solid phase extraction (SPE, Bond Elut NEXUS) from fluoride-mediated regeneration of blank human plasma, LOD (on EIC at m/z 99 except for GAF (m/z 126)) were 25-140 pg/mL with sharp peak shapes. The reaction recoveries in fluoride-mediated regeneration of plasma, which was inhibited by GB, GD, GA, GF, VX, and Russian VX (10 ng/mL), were 49-114% except for GD (10%). The concentration levels of 0.3-1 ng/mL of nerve agents in plasma could be determined.
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Affiliation(s)
- Yasuo Seto
- National Research Institute of Police Science, Kashiwa, Chiba 277-0882, Japan.
| | | | - Asuka Komano
- National Research Institute of Police Science, Kashiwa, Chiba 277-0882, Japan
| | - Tomoki Nagoya
- National Research Institute of Police Science, Kashiwa, Chiba 277-0882, Japan
| | - Ryoichi Sasano
- AiSTI SCIENCE Ltd, Assort Kuroda 2F, 120-6, Kuroda, Wakayama 640-8341, Japan
| | - Shunsuke Matsuo
- AiSTI SCIENCE Ltd, Assort Kuroda 2F, 120-6, Kuroda, Wakayama 640-8341, Japan
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C-547, a 6-methyluracil derivative with long-lasting binding and rebinding on acetylcholinesterase: Pharmacokinetic and pharmacodynamic studies. Neuropharmacology 2018; 131:304-315. [DOI: 10.1016/j.neuropharm.2017.12.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/07/2017] [Accepted: 12/19/2017] [Indexed: 01/09/2023]
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Onder S, David E, Tacal O, Schopfer LM, Lockridge O. Hupresin Retains Binding Capacity for Butyrylcholinesterase and Acetylcholinesterase after Sanitation with Sodium Hydroxide. Front Pharmacol 2017; 8:713. [PMID: 29066970 PMCID: PMC5641355 DOI: 10.3389/fphar.2017.00713] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 09/25/2017] [Indexed: 12/01/2022] Open
Abstract
Hupresin is a new affinity resin that binds butyrylcholinesterase (BChE) in human plasma and acetylcholinesterase (AChE) solubilized from red blood cells (RBC). Hupresin is available from the CHEMFORASE company. BChE in human plasma binds to Hupresin and is released with 0.1 M trimethylammonium bromide (TMA) with full activity and 10-15% purity. BChE immunopurified from plasma by binding to immobilized monoclonal beads has fewer contaminating proteins than the one-step Hupresin-purified BChE. However, when affinity chromatography on Hupresin follows ion exchange chromatography at pH 4.5, BChE is 99% pure. The membrane bound AChE, solubilized from human RBC with 0.6% Triton X-100, binds to Hupresin and remains bound during washing with sodium chloride. Human AChE is not released in significant quantities with non-denaturing solvents, but is recovered in 1% trifluoroacetic acid. The denatured, partially purified AChE is useful for detecting exposure to nerve agents by mass spectrometry. Our goal was to determine whether Hupresin retains binding capacity for BChE and AChE after Hupresin is washed with 0.1 M NaOH. A 2 mL column of Hupresin equilibrated in 20 mM TrisCl pH 7.5 was used in seven consecutive trials to measure binding and recovery of BChE from 100 mL human plasma. Between each trial the Hupresin was washed with 10 column volumes of 0.1 M sodium hydroxide. A similar trial was conducted with red blood cell AChE in 0.6% Triton X-100. It was found that the binding capacity for BChE and AChE was unaffected by washing Hupresin with 0.1 M sodium hydroxide. Hupresin could be washed with sodium hydroxide at least seven times without losing binding capacity.
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Affiliation(s)
- Seda Onder
- Department of Biochemistry, School of Pharmacy, Hacettepe University, Ankara, Turkey
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | | | - Ozden Tacal
- Department of Biochemistry, School of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Lawrence M. Schopfer
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States
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Dafferner AJ, Schopfer LM, Xiao G, Cashman JR, Yerramalla U, Johnson RC, Blake TA, Lockridge O. Immunopurification of Acetylcholinesterase from Red Blood Cells for Detection of Nerve Agent Exposure. Chem Res Toxicol 2017; 30:1897-1910. [PMID: 28892361 PMCID: PMC5646370 DOI: 10.1021/acs.chemrestox.7b00209] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Nerve agents and
organophosphorus pesticides make a covalent bond
with the active site serine of acetylcholinesterase (AChE), resulting
in inhibition of AChE activity and toxic symptoms. AChE in red blood
cells (RBCs) serves as a surrogate for AChE in the nervous system.
Mass spectrometry analysis of adducts on RBC AChE could provide evidence
of exposure. Our goal was to develop a method of immunopurifying human
RBC AChE in quantities adequate for detecting exposure by mass spectrometry.
For this purpose, we immobilized 3 commercially available anti-human
acetylcholinesterase monoclonal antibodies (AE-1, AE-2, and HR2) plus
3 new monoclonal antibodies. The monoclonal antibodies were characterized
for binding affinity, epitope mapping by pairing analysis, and nucleotide
and amino acid sequences. AChE was solubilized from frozen RBCs with
1% (v/v) Triton X-100. A 16 mL sample containing 5.8 μg of RBC
AChE was treated with a quantity of soman model compound that inhibited
50% of the AChE activity. Native and soman-inhibited RBC AChE samples
were immunopurified on antibody–Sepharose beads. The immunopurified
RBC AChE was digested with pepsin and analyzed by liquid chromatography
tandem mass spectrometry on a 6600 Triple-TOF mass spectrometer. The
aged soman-modified PheGlyGluSerAlaGlyAlaAlaSer (FGESAGAAS) peptide
was detected using a targeted analysis method. It was concluded that
all 6 monoclonal antibodies could be used to immunopurify RBC AChE
and that exposure to nerve agents could be detected as adducts on
the active site serine of RBC AChE.
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Affiliation(s)
- Alicia J Dafferner
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
| | - Lawrence M Schopfer
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
| | - Gaoping Xiao
- Syd Labs, Inc , Natick, Massachusetts 01760, United States
| | - John R Cashman
- Human BioMolecular Research Institute , 5310 Eastgate Mall, San Diego, California 92121, United States
| | - Udaya Yerramalla
- Precision Antibody , 91330 Red Branch Rd, Columbia, Maryland 21045, United States
| | - Rudolph C Johnson
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , 4770 Buford Highway, Chamblee, Georgia 30341, United States
| | - Thomas A Blake
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , 4770 Buford Highway, Chamblee, Georgia 30341, United States
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
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Liu CC, Huang GL, Xi HL, Liu SL, Liu JQ, Yu HL, Zhou SK, Liang LH, Yuan L. Simultaneous quantification of soman and VX adducts to butyrylcholinesterase, their aged methylphosphonic acid adduct and butyrylcholinesterase in plasma using an off-column procainamide-gel separation method combined with UHPLC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1036-1037:57-65. [PMID: 27718463 DOI: 10.1016/j.jchromb.2016.09.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/23/2016] [Accepted: 09/30/2016] [Indexed: 10/20/2022]
Abstract
This work describes a novel and sensitive non-isotope dilution method for simultaneous quantification of organophosphorus nerve agents (OPNAs) soman (GD) and VX adducts to butyrylcholinesterase (BChE), their aged methylphosphonic acid (MeP) adduct and unadducted BChE in plasma exposed to OPNA. OPNA-BChE adducts were isolated with an off-column procainamide-gel separation (PGS) from plasma, and then digested with pepsin into specific adducted FGES*AGAAS nonapeptide (NP) biomarkers. The resulting NPs were detected by UHPLC-MS/MS MRM. The off-column PGS method can capture over 90% of BChE, MeP-BChE, VX-BChE and GD-BChE from their respective plasma materials. One newly designed and easily synthesized phosphorylated BChE nonapeptide with one Gly-to-Ala mutation was successfully reported to serve as internal standard instead of traditional isotopically labeled BChE nonapeptide. The linear range of calibration curves were from 1.00-200ngmL-1 for VX-NP, 2.00-200ngmL-1 for GD-NP and MeP-NP (R2≥0.995), and 3.00-200ngmL-1 for BChE NP (R2≥0.990). The inter-day precision had relative standard deviation (%RSD) of <8.89%, and the accuracy ranged between 88.9-120%. The limit of detection was calculated to be 0.411, 0.750, 0.800 and 1.43ngmL-1 for VX-NP, GD-NP, MeP-NP and BChE NP, respectively. OPNA-exposed quality control plasma samples were characterized as part of method validation. Investigation of plasma samples unexposed to OPNA revealed no baseline values or interferences. Using the off-column PGS method combined with UHPLC-MS/MS, VX-NP and GD-NP adducts can be unambiguously detected with high confidence in 0.10ngmL-1 and 0.50ngmL-1 of exposed human plasma respectively, only requiring 0.1mL of plasma sample and taking about four hours without special sample preparation equipment. These improvements make it a simple, sensitive and robust PGS-UHPLC-MS/MS method, and this method will become an attractive alternative to immunomagnetic separation (IMS) method and a useful diagnostic tool for retrospective detection of OPNA exposure with high confidence. Furthermore, using the developed method, the adducted BChE levels from VX and GD-exposed (0.10-100ngmL-1) plasma samples were completely characterized, and the fact that VX being more active and specific to BChE than GD was re-confirmed.
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Affiliation(s)
- Chang-Cai Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Gui-Lan Huang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Hai-Ling Xi
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Shi-Lei Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China.
| | - Jing-Quan Liu
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Hui-Lan Yu
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Shi-Kun Zhou
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China; Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Long-Hui Liang
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Ling Yuan
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
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Chen X, Zheng X, Zhan M, Zhou Z, Zhan CG, Zheng F. Metabolic Enzymes of Cocaine Metabolite Benzoylecgonine. ACS Chem Biol 2016; 11:2186-94. [PMID: 27224254 DOI: 10.1021/acschembio.6b00277] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cocaine is one of the most addictive drugs without a U.S. Food and Drug Administration (FDA)-approved medication. Enzyme therapy using an efficient cocaine-metabolizing enzyme is recognized as the most promising approach to cocaine overdose treatment. The actual enzyme, known as RBP-8000, under current clinical development for cocaine overdose treatment is our previously designed T172R/G173Q mutant of bacterial cocaine esterase (CocE). The T172R/G173Q mutant is effective in hydrolyzing cocaine but inactive against benzoylecgonine (a major, biologically active metabolite of cocaine). Unlike cocaine itself, benzoylecgonine has an unusually stable zwitterion structure resistant to further hydrolysis in the body and environment. In fact, benzoylecgonine can last in the body for a very long time (a few days) and, thus, is responsible for the long-term toxicity of cocaine and a commonly used marker for drug addiction diagnosis in pre-employment drug tests. Because CocE and its mutants are all active against cocaine and inactive against benzoylecgonine, one might simply assume that other enzymes that are active against cocaine are also inactive against benzoylecgonine. Here, through combined computational modeling and experimental studies, we demonstrate for the first time that human butyrylcholinesterase (BChE) is actually active against benzoylecgonine, and that a rationally designed BChE mutant can not only more efficiently accelerate cocaine hydrolysis but also significantly hydrolyze benzoylecgonine in vitro and in vivo. This sets the stage for advanced studies to design more efficient mutant enzymes valuable for the development of an ideal cocaine overdose enzyme therapy and for benzoylecgonine detoxification in the environment.
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Affiliation(s)
- Xiabin Chen
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Xirong Zheng
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Max Zhan
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Ziyuan Zhou
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Chang-Guo Zhan
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
| | - Fang Zheng
- Molecular Modeling and Biopharmaceutical
Center and Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, Kentucky 40536, United States
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Singh SK, Singh VK, Yadav BK, Nakade UP, Kumari P, Srivastava MK, Sharma A, Choudhary S, Swain D, Garg SK. Potential association of reduced cholinesterase activity with Trypanosoma evansi pathogenesis in buffaloes. Vet Parasitol 2016; 225:29-32. [PMID: 27369572 DOI: 10.1016/j.vetpar.2016.05.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/18/2016] [Accepted: 05/23/2016] [Indexed: 11/24/2022]
Abstract
The present study aimed to investigate the association of cholinesterase activity with trypanosomosis in buffaloes. Thirty-three clinical cases of trypanosomosis in water buffaloes, found positive for trypomastigotes of T. evansi on blood smear examination, were divided into two groups based on clinical manifestations. Twenty diseased buffaloes revealing only common clinical signs were allocated to Group I, while the remaining 13 buffaloes showing common clinical manifestations along with neurological disturbances were allocated to Group II. Twelve clinically healthy buffaloes, free from any haemoprotozoa infection, were kept as healthy control (Group III). Blood samples were collected from buffaloes of all three groups to determine serum cholinesterase activity. Compared to buffaloes of healthy control group, cholinesterase activity in T. evansi-infected buffaloes of Group I and II was significantly (P<0.001) lower. However, no significant difference was observed in cholinesterase activity between the T. evansi-infected buffaloes exhibiting neurological disorders and no neurological disorders. Summing up, reduced cholinesterase activity seems to be associated with the pathogenesis of natural T. evansi infection and its clinical manifestations in buffaloes possibly by evading immune response. Further studies are warranted on association of cholinesterase activity in T. evansi-infected buffaloes with neurological disorders.
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Affiliation(s)
- Shanker K Singh
- Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India.
| | - Vivek K Singh
- Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | - Brajesh K Yadav
- Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | - Udayraj P Nakade
- Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | | | - Mukesh K Srivastava
- Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | - Abhishek Sharma
- Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | - Soumen Choudhary
- Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | - Dilip Swain
- Department of Animal Physiology, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
| | - Satish K Garg
- Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, 281 001 U.P., India
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Schopfer LM, Lockridge O, Brimijoin S. Pure human butyrylcholinesterase hydrolyzes octanoyl ghrelin to desacyl ghrelin. Gen Comp Endocrinol 2015; 224:61-8. [PMID: 26073531 DOI: 10.1016/j.ygcen.2015.05.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 05/20/2015] [Accepted: 05/27/2015] [Indexed: 10/23/2022]
Abstract
The ghrelin hormone is a 28 amino acid peptide esterified on serine 3 with octanoic acid. Ghrelin is inactivated by hydrolysis of the ester bond. Previous studies have relied on inhibitors to identify human butyrylcholinesterase (BChE) as the hydrolase in human plasma that converts ghrelin to desacyl ghrelin. The reaction of BChE with ghrelin is unusual because the rate of hydrolysis is very slow and the substrate is ten times larger than standard BChE substrates. These unusual features prompted us to re-examine the reaction, using human BChE preparations that were more than 98% pure. Conversion of ghrelin to desacyl ghrelin was monitored by MALDI TOF mass spectrometry. It was found that 5 different preparations of pure human BChE all hydrolyzed ghrelin, including BChE purified from human plasma, from Cohn fraction IV-4, BChE immunopurified by binding to monoclonals mAb2 and B2 18-5, and recombinant human BChE purified from culture medium. We reasoned that it was unlikely that a common contaminant that could be responsible for ghrelin hydrolysis would appear in all of these preparations. km was <1 μM, and kcat was ~1.4 min(-1). A Michaelis-Menten analysis employing these kinetic values together with serum concentrations of ghrelin and BChE demonstrated that BChE could hydrolyze all of the ghrelin in serum in ~1 h. It was concluded that BChE is physiologically relevant for the hydrolysis of ghrelin.
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Affiliation(s)
- Lawrence M Schopfer
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950, USA.
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950, USA.
| | - Stephen Brimijoin
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA.
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Radiometric assay of ghrelin hydrolase activity and 3H-ghrelin distribution into mouse tissues. Biochem Pharmacol 2015; 98:732-9. [PMID: 26514871 DOI: 10.1016/j.bcp.2015.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/21/2015] [Indexed: 11/24/2022]
Abstract
A high-throughput radiometric assay was developed to characterize enzymatic hydrolysis of ghrelin and to track the peptide's fate in vivo. The assay is based on solvent partitioning of [(3)H]-octanoic acid liberated from [(3)H]-octanoyl ghrelin during enzymatic hydrolysis. This simple and cost-effective method facilitates kinetic analysis of ghrelin hydrolase activity of native and mutated butyrylcholinesterases or carboxylesterases from multiple species. In addition, the assay's high sensitivity facilitates ready evaluation of ghrelin's pharmacokinetics and tissue distribution in mice after i.v. bolus administration of radiolabeled peptide.
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13
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Kinetic characterization of human butyrylcholinesterase mutants for the hydrolysis of cocaethylene. Biochem J 2014; 460:447-57. [PMID: 24870023 DOI: 10.1042/bj20140360] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It is known that the majority of cocaine users also consume alcohol. Alcohol can react with cocaine to produce a significantly more cytotoxic compound, cocaethylene. Hence a truly valuable cocaine-metabolizing enzyme as treatment for cocaine abuse/overdose should be efficient for not only cocaine itself, but also cocaethylene. The catalytic parameters (kcat and KM) of human BChE (butyrylcholinesterase) and two mutants (known as cocaine hydrolases E14-3 and E12-7) for cocaethylene are characterized in the present study, for the first time, in comparison with those for cocaine. On the basis of the obtained kinetic data, wild-type human BChE has a lower catalytic activity for cocaethylene (kcat=3.3 min(-1), KM=7.5 μM and kcat/KM=4.40 × 10(5) M(-1)·min(-1)) compared with its catalytic activity for (-)-cocaine. E14-3 and E12-7 have a considerably improved catalytic activity against cocaethylene compared with the wild-type BChE. E12-7 is identified as the most efficient enzyme for hydrolysing cocaethylene in addition to its high activity for (-)-cocaine. E12-7 has an 861-fold improved catalytic efficiency for cocaethylene (kcat=3600 min(-1), KM=9.5 μM and kcat/KM=3.79 × 10(8) M(-1)·min(-1)). It has been demonstrated that E12-7 as an exogenous enzyme can indeed rapidly metabolize cocaethylene in rats. Further kinetic modelling has suggested that E12-7 with an identical concentration as that of the endogenous BChE in human plasma can effectively eliminate (-)-cocaine, cocaethylene and norcocaine in simplified kinetic models of cocaine abuse and overdose associated with the concurrent use of cocaine and alcohol.
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14
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Kinetic characterization of high-activity mutants of human butyrylcholinesterase for the cocaine metabolite norcocaine. Biochem J 2014; 457:197-206. [PMID: 24125115 DOI: 10.1042/bj20131100] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It has been known that cocaine produces its toxic and physiological effects through not only cocaine itself, but also norcocaine formed from cocaine oxidation catalysed by microsomal CYP (cytochrome P450) 3A4 in the human liver. The catalytic parameters (kcat and Km) of human BChE (butyrylcholinesterase) and its three mutants (i.e. A199S/S287G/A328W/Y332G, A199S/F227A/S287G/A328W/E441D and A199S/F227A/S287G/A328W/Y332G) for norcocaine have been characterized in the present study for the first time and compared with those for cocaine. On the basis of the obtained kinetic data, wild-type human BChE has a significantly lower catalytic activity for norcocaine (kcat=2.8 min(-1), Km=15 μM and kcat/Km=1.87 × 10(5) M(-1)·min(-1)) compared with its catalytic activity for (-)-cocaine. The BChE mutants examined in the present study have considerably improved catalytic activities against both cocaine and norcocaine compared with the wild-type enzyme. Within the enzymes examined in the present study, the A199S/F227A/S287G/A328W/Y332G mutant (CocH3) is identified as the most efficient enzyme for hydrolysing both cocaine and norcocaine. CocH3 has a 1080-fold improved catalytic efficiency for norcocaine (kcat=2610 min(-1), Km=13 μM and kcat/Km=2.01 × 10(8) M(-1)·min(-1)) and a 2020-fold improved catalytic efficiency for cocaine. It has been demonstrated that CocH3 as an exogenous enzyme can rapidly metabolize norcocaine, in addition to cocaine, in rats. Further kinetic modelling has suggested that CocH3 with an identical concentration with that of the endogenous BChE in human plasma can effectively eliminate both cocaine and norcocaine in a simplified kinetic model of cocaine abuse.
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15
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Ge X, Zhang W, Lin Y, Du D. Magnetic Fe3O4@TiO2 nanoparticles-based test strip immunosensing device for rapid detection of phosphorylated butyrylcholinesterase. Biosens Bioelectron 2013; 50:486-91. [DOI: 10.1016/j.bios.2013.07.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/28/2013] [Accepted: 07/09/2013] [Indexed: 11/28/2022]
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16
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Abney CW, Knaack JLS, Ali AAI, Johnson RC. Novel Dual-Mode Immunomagnetic Method for Studying Reactivation of Nerve Agent-Inhibited Butyrylcholinesterase. Chem Res Toxicol 2013; 26:775-82. [DOI: 10.1021/tx4000717] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carter W. Abney
- Oak Ridge Institute for Science
and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Jennifer L. S. Knaack
- Division of Laboratory Sciences,
National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Ahmed A. I. Ali
- Oak Ridge Institute for Science
and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Rudolph C. Johnson
- Division of Laboratory Sciences,
National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
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17
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Zhang X, Wang H, Yang C, Du D, Lin Y. Preparation, characterization of Fe3O4 at TiO2 magnetic nanoparticles and their application for immunoassay of biomarker of exposure to organophosphorus pesticides. Biosens Bioelectron 2013; 41:669-74. [DOI: 10.1016/j.bios.2012.09.047] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/20/2012] [Accepted: 09/22/2012] [Indexed: 10/27/2022]
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18
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Knaack JS, Zhou Y, Abney CW, Jacob JT, Prezioso SM, Hardy K, Lemire SW, Thomas J, Johnson RC. A High-Throughput Diagnostic Method for Measuring Human Exposure to Organophosphorus Nerve Agents. Anal Chem 2012; 84:9470-7. [DOI: 10.1021/ac302301w] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jennifer S. Knaack
- Emergency Response
and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Yingtao Zhou
- Emergency Response
and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Carter W. Abney
- Oak Ridge Institute for Science and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Justin T. Jacob
- Oak Ridge Institute for Science and Education Fellow at the Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee,
Georgia 30341, United States
| | - Samantha M. Prezioso
- IHRC, Inc., Contractor at the Centers
for Disease Control and Prevention, 2
Ravinia Drive, Suite 1260, Atlanta, Georgia 30346, United States
| | - Katelyn Hardy
- Emergency Response
and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Sharon W. Lemire
- Emergency Response
and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Jerry Thomas
- Emergency Response
and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
| | - Rudolph C. Johnson
- Emergency Response
and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway,
MS F44, Chamblee, Georgia 30341, United States
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19
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Naik RS, Liu W, Saxena A. Development and validation of a simple assay for the determination of cholinesterase activity in whole blood of laboratory animals. J Appl Toxicol 2012; 33:290-300. [DOI: 10.1002/jat.2730] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 12/28/2011] [Accepted: 01/02/2012] [Indexed: 11/09/2022]
Affiliation(s)
- Ramachandra S. Naik
- Division of Biochemistry; Walter Reed Army Institute of Research; Silver Spring; MD; 20910; USA
| | - Weiyi Liu
- Division of Biochemistry; Walter Reed Army Institute of Research; Silver Spring; MD; 20910; USA
| | - Ashima Saxena
- Division of Biochemistry; Walter Reed Army Institute of Research; Silver Spring; MD; 20910; USA
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20
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Schopfer LM, Lockridge O. Analytical approaches for monitoring exposure to organophosphorus and carbamate agents through analysis of protein adducts. Drug Test Anal 2012; 4:246-61. [DOI: 10.1002/dta.1325] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 09/29/2011] [Accepted: 10/02/2011] [Indexed: 12/16/2022]
Affiliation(s)
| | - Oksana Lockridge
- Eppley Institute; University of Nebraska Medical Center; Omaha; NE
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21
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Du D, Wang J, Wang L, Lu D, Smith JN, Timchalk C, Lin Y. Magnetic Electrochemical Sensing Platform for Biomonitoring of Exposure to Organophosphorus Pesticides and Nerve Agents Based on Simultaneous Measurement of Total Enzyme Amount and Enzyme Activity. Anal Chem 2011; 83:3770-7. [DOI: 10.1021/ac200217d] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dan Du
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Jun Wang
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Limin Wang
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Donglai Lu
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Jordan N. Smith
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Charles Timchalk
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Yuehe Lin
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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22
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Sporty JLS, Lemire SW, Jakubowski EM, Renner JA, Evans RA, Williams RF, Schmidt JG, van der Schans MJ, Noort D, Johnson RC. Immunomagnetic separation and quantification of butyrylcholinesterase nerve agent adducts in human serum. Anal Chem 2010; 82:6593-600. [PMID: 20617824 DOI: 10.1021/ac101024z] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel method for extracting butyrylcholinesterase (BuChE) from serum as a means of identifying and measuring nerve agent adducts to human BuChE is presented here. Antibutyrylcholinesterase monoclonal antibodies were conjugated to protein-G ferromagnetic particles and mixed with 500 microL serum samples. The particle-antibody-BuChE product was rinsed and directly digested with pepsin. Native and isotopically enriched nonapeptides corresponding to the pepsin digest products for uninhibited BuChE, and sarin, cyclohexylsarin, VX, and Russian VX nerve agent-inhibited BuChE were synthesized for use as calibrators and internal standards, respectively. Internal standards were added to the filtered digest sample, and the samples were quantified via high performance liquid chromatography-isotope dilution-tandem mass spectrometry. The ratio of adducted to total BuChE nonapeptides was calculated for each nerve agent-exposed serum sample using data collected in a single chromatogram. Nerve agent-inhibited quality control serum pools were characterized as part of method validation; the method was observed to have extremely low background noise. The measurement of both uninhibited and inhibited BuChE peptides compensated for any variations in the pepsin digestion before the internal standard peptide was added to the sample and may prove useful in individualizing patient results following a nerve agent exposure.
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Affiliation(s)
- Jennifer L S Sporty
- Emergency Response and Air Toxicants Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, MS F44, Chamblee, Georgia 30341, USA
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23
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Da Silva A, Spanevello R, Stefanello N, Wolkmer P, Costa M, Zanette R, Lopes S, Santurio J, Schetinger M, Monteiro S. Influence of Trypanosoma evansi in blood, plasma, and brain cholinesterase of experimentally infected cats. Res Vet Sci 2010; 88:281-4. [DOI: 10.1016/j.rvsc.2009.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Revised: 08/26/2009] [Accepted: 08/28/2009] [Indexed: 12/11/2022]
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24
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Comparison of methods used for the determination of cholinesterase activity in whole blood. Chem Biol Interact 2008; 175:298-302. [DOI: 10.1016/j.cbi.2008.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 04/30/2008] [Accepted: 05/02/2008] [Indexed: 11/20/2022]
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25
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Huang YJ, Lundy PM, Lazaris A, Huang Y, Baldassarre H, Wang B, Turcotte C, Côté M, Bellemare A, Bilodeau AS, Brouillard S, Touati M, Herskovits P, Bégin I, Neveu N, Brochu E, Pierson J, Hockley DK, Cerasoli DM, Lenz DE, Wilgus H, Karatzas CN, Langermann S. Substantially improved pharmacokinetics of recombinant human butyrylcholinesterase by fusion to human serum albumin. BMC Biotechnol 2008; 8:50. [PMID: 18485214 PMCID: PMC2415180 DOI: 10.1186/1472-6750-8-50] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 05/16/2008] [Indexed: 11/10/2022] Open
Abstract
Background Human butyrylcholinesterase (huBChE) has been shown to be an effective antidote against multiple LD50 of organophosphorus compounds. A prerequisite for such use of huBChE is a prolonged circulatory half-life. This study was undertaken to produce recombinant huBChE fused to human serum albumin (hSA) and characterize the fusion protein. Results Secretion level of the fusion protein produced in vitro in BHK cells was ~30 mg/liter. Transgenic mice and goats generated with the fusion constructs expressed in their milk a bioactive protein at concentrations of 0.04–1.1 g/liter. BChE activity gel staining and a size exclusion chromatography (SEC)-HPLC revealed that the fusion protein consisted of predominant dimers and some monomers. The protein was confirmed to have expected molecular mass of ~150 kDa by Western blot. The purified fusion protein produced in vitro was injected intravenously into juvenile pigs for pharmacokinetic study. Analysis of a series of blood samples using the Ellman assay revealed a substantial enhancement of the plasma half-life of the fusion protein (~32 h) when compared with a transgenically produced huBChE preparation containing >70% tetramer (~3 h). In vitro nerve agent binding and inhibition experiments indicated that the fusion protein in the milk of transgenic mice had similar inhibition characteristics compared to human plasma BChE against the nerve agents tested. Conclusion Both the pharmacokinetic study and the in vitro nerve agent binding and inhibition assay suggested that a fusion protein retaining both properties of huBChE and hSA is produced in vitro and in vivo. The production of the fusion protein in the milk of transgenic goats provided further evidence that sufficient quantities of BChE/hSA can be produced to serve as a cost-effective and reliable source of BChE for prophylaxis and post-exposure treatment.
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Affiliation(s)
- Yue-Jin Huang
- PharmAthene Canada Inc, (formally Nexia Biotechnologies Inc,), 7150 Alexander-Fleming, Montreal, QC H4S 2C8, Canada.
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Salles JB, Cunha Bastos VLF, Silva Filho MV, Machado OLT, Salles CMC, Giovanni de Simone S, Cunha Bastos J. A novel butyrylcholinesterase from serum of Leporinus macrocephalus, a Neotropical fish. Biochimie 2006; 88:59-68. [PMID: 16085351 DOI: 10.1016/j.biochi.2005.06.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2005] [Accepted: 06/24/2005] [Indexed: 11/27/2022]
Abstract
We show here that serum of piaussu, a Neotropical characin fish, has the highest butyrylcholinesterase activity so far described for humans and fish. To clarify whether this cholinesterase could protect piaussu against anticholinesterase pesticides by scavenging organophosphates, we purified it 1700-fold, with a yield of 80%. Augmenting concentrations (from 0.01 to 20 mM) of butyrylthiocholine activated it. The pure enzyme was highly inhibited by chlorpyriphos-oxon (ki=10,434x10(6) M-1 min-1) and by the specific butyrylcholinesterase inhibitor, isoOMPA (ki=45.7x10(6) M-1 min-1). Electrophoresis of total serum and 2-D electrophoresis of the purified cholinesterase showed that some enzyme molecules could circulate in piaussu serum as heterogeneously glycosylated dimers. The enzyme's N-terminal sequence was similar to sequences found for butyrylcholinesterase from sera of other vertebrates. Altogether, our data present a novel butyrylcholinesterase with the potential of protecting a fish from poisoning by organophosphates.
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Affiliation(s)
- J B Salles
- Department of Biochemistry, UERJ, Av. Professor Manuel de Abreu, 444, Rio de Janeiro, RJ 20550-170, Brazil
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