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Li H, Lu C, Liu Z, Xiang F, Liu B, Wang H, Chang J, Pan L, Chen Y, Chen J. Advancements in bioscavenger mediated detoxification of organophosphorus poisoning. Toxicol Res (Camb) 2024; 13:tfae089. [PMID: 38863796 PMCID: PMC11163184 DOI: 10.1093/toxres/tfae089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024] Open
Abstract
Background Organophosphorus compounds, widely used in agriculture and industry, pose a serious threat to human health due to their acute neurotoxicity. Although traditional interventions for organophosphate poisoning are effective, they often come with significant side effects. Objective This paper aims to evaluate the potential of enzymes within biological organisms as organophosphorus bioclearing agents. It analyses the technical challenges in current enzyme research, such as substrate specificity, stereoselectivity, and immunogenicity, while exploring recent advancements in the field. Methods A comprehensive review of literature related to detoxifying enzymes or proteins was conducted. Existing studies on organophosphorus bioclearing agents were summarised, elucidating the biological detoxification mechanisms, with a particular focus on advancements in protein engineering and novel delivery methods. Results Current bioclearing agents can be categorised into stoichiometric and catalytic bioclearing agents, both of which have shown some success in preventing organophosphate poisoning. Technological advancements have significantly improved various properties of bioclearing agents, yet challenges remain, particularly in substrate specificity, stereoselectivity, and immunogenicity. Future research will focus on expanding the substrate spectrum, enhancing catalytic efficiency, prolonging in vivo half-life, and developing convenient administration methods. Conclusion With the progression of clinical trials, bioclearing agents are expected to become widely used as a new generation of therapeutic organophosphate detoxifiers.
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Affiliation(s)
- Hexi Li
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
- Unit No. 31666 of PLA, 1 New City Courtyard, Jinyang Town, Liangzhou District, Wuwei, Gansu 733000, China
| | - Cong Lu
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
- Unit No. 94347 of PLA, 24 Wenfu Road, Shenhe District, Shenyang, Liaoning 110000, China
| | - Zhenmin Liu
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Fengshun Xiang
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Bo Liu
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Hongjuan Wang
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Jie Chang
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Li Pan
- State Key Laboratory of NBC Protection for Civilians, 30 South Central Street, Yangfang Town, Changping District, Beijing 102205, P. R. China
| | - Youwei Chen
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Jingfei Chen
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
- Unit No. 32169 of PLA, 100 Shuangyong East Road, Nyingchi, Tibet 860000, China
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Belinskaya T, Saxena A. Low levels of endogenous cholinesterases support the choice of cows, sheep and goats for the transgenic expression of human butyrylcholinesterase in milk. Chem Biol Interact 2023; 383:110691. [PMID: 37659623 DOI: 10.1016/j.cbi.2023.110691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/14/2023] [Accepted: 08/30/2023] [Indexed: 09/04/2023]
Abstract
Butyrylcholinesterase purified from human plasma (Hu BChE) as well as recombinant (r) Hu BChE are candidate enzymes that can protect humans from toxicity of organophosphorus compounds (OPs). Domestic animals such as cows, pigs, sheep, and goats have been used for the transgenic expression of a variety of valuable therapeutic proteins. Indeed, rHu BChE was successfully expressed in the milk of transgenic goats, but the presence of any endogenous cholinesterases (ChE) in milk would interfere with the isolation of expressed rHu BChE. The aim of this study was to determine the presence of endogenous ChEs in bovine, ovine, caprine, and porcine milk to determine the suitability of these species for the production of rHu BChE. Using acetyl- and butyryl- thiocholine as substrates, ChE activity (2-4 U/mL) was detected in pig milk only. ChE activities in milk from other animals were <0.01 U/mL and could only be detected following enrichment on procainamide-Sepharose gel. Two different methods based on measuring activity in the presence of acetylcholinesterase (AChE)- or BChE- specific inhibitors were used to estimate the proportions of AChE and BChE activities in enriched milk. Monoclonal antibodies (MAbs), against fetal bovine serum AChE that recognize AChEs from ruminants only, were also used to confirm the identity of AChEs. While bovine and ovine milk contain both AChE and BChE activities, caprine and porcine milk contain predominantly BChE activity. The presence of very low ChE activity supports the choice of cows, sheep, and goats for the transgenic expression of rHu BChE in milk.
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Affiliation(s)
- Tatyana Belinskaya
- 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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Allard JL, Shields KA, Munro T, Lua LHL. Design and production strategies for developing a recombinant butyrylcholinesterase medical countermeasure for Organophosphorus poisoning. Chem Biol Interact 2022; 363:109996. [PMID: 35654125 DOI: 10.1016/j.cbi.2022.109996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/06/2022] [Accepted: 05/24/2022] [Indexed: 11/25/2022]
Abstract
Organophosphorus nerve agents represent a serious chemical threat due to their ease of production and scale of impact. The recent use of the nerve agent Novichok has re-emphasised the need for broad-spectrum medical countermeasures (MCMs) to these agents. However, current MCMs are limited. Plasma derived human butyrylcholinesterase (huBChE) is a promising novel bioscavenger MCM strategy, but is prohibitively expensive to isolate from human plasma at scale. Efforts to produce recombinant huBChE (rBChE) in various protein expression platforms have failed to achieve key critical attributes of huBChE such as circulatory half-life. These proteins often lack critical features such as tetrameric structure and requisite post-translational modifications. This review evaluates previous attempts to generate rBChE and assesses recent advances in mammalian cell expression and protein engineering strategies that could be deployed to achieve the required half-life and yield for a viable rBChE MCM. This includes the addition of a proline-rich attachment domain, fusion proteins, post translational modifications, expression system selection and optimised downstream processes. Whilst challenges remain, a combinatorial approach of these strategies demonstrates potential as a technically feasible approach to achieving a bioactive and cost effective bioscavenger MCM.
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Affiliation(s)
- Joanne L Allard
- Defence Science and Technology Group, Fishermans Bend, Victoria, 3207, Australia; The University of Queensland, Brisbane, Queensland, 4072, Australia.
| | - Katherine A Shields
- Defence Science and Technology Group, Fishermans Bend, Victoria, 3207, Australia
| | - TrentP Munro
- The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Linda H L Lua
- The University of Queensland, Brisbane, Queensland, 4072, Australia
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Gentzsch C, Hoffmann M, Ohshima Y, Nose N, Chen X, Higuchi T, Decker M. Synthesis and Initial Characterization of a Selective, Pseudo-irreversible Inhibitor of Human Butyrylcholinesterase as PET Tracer. ChemMedChem 2021; 16:1427-1437. [PMID: 33645891 PMCID: PMC8247983 DOI: 10.1002/cmdc.202000942] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/19/2021] [Indexed: 02/06/2023]
Abstract
The enzyme butyrylcholinesterase (BChE) represents a promising target for imaging probes to potentially enable early diagnosis of neurodegenerative diseases like Alzheimer's disease (AD) and to monitor disease progression in some forms of cancer. In this study, we present the design, facile synthesis, in vitro and preliminary ex vivo and in vivo evaluation of a morpholine-based, selective inhibitor of human BChE as a positron emission tomography (PET) tracer with a pseudo-irreversible binding mode. We demonstrate a novel protecting group strategy for 18 F radiolabeling of carbamate precursors and show that the inhibitory potency as well as kinetic properties of our unlabeled reference compound were retained in comparison to the parent compound. In particular, the prolonged duration of enzyme inhibition of such a morpholinocarbamate motivated us to design a PET tracer, possibly enabling a precise mapping of BChE distribution.
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Affiliation(s)
- Christian Gentzsch
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius-Maximilians-University of WürzburgAm Hubland97074WürzburgGermany
| | - Matthias Hoffmann
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius-Maximilians-University of WürzburgAm Hubland97074WürzburgGermany
| | - Yasuhiro Ohshima
- Comprehensive Heart Failure CenterUniversity Hospital of WürzburgAm Schwarzenberg 1597078WürzburgGermany
- Department of Nuclear MedicineUniversity Hospital of WürzburgOberdürrbacher Straße 697080WürzburgGermany
| | - Naoko Nose
- Graduate School of MedicineDentistry and Pharmaceutical SciencesOkayama University2-5-1 Shikata-cho, Kita-kuOkayamaJapan
| | - Xinyu Chen
- Department of Nuclear MedicineUniversity Hospital of AugsburgStenglinstraße 286156AugsburgGermany
- Comprehensive Heart Failure CenterUniversity Hospital of WürzburgAm Schwarzenberg 1597078WürzburgGermany
- Department of Nuclear MedicineUniversity Hospital of WürzburgOberdürrbacher Straße 697080WürzburgGermany
| | - Takahiro Higuchi
- Comprehensive Heart Failure CenterUniversity Hospital of WürzburgAm Schwarzenberg 1597078WürzburgGermany
- Department of Nuclear MedicineUniversity Hospital of WürzburgOberdürrbacher Straße 697080WürzburgGermany
- Graduate School of MedicineDentistry and Pharmaceutical SciencesOkayama University2-5-1 Shikata-cho, Kita-kuOkayamaJapan
| | - Michael Decker
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius-Maximilians-University of WürzburgAm Hubland97074WürzburgGermany
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Organophosphate detoxification by membrane-engineered red blood cells. Acta Biomater 2021; 124:270-281. [PMID: 33529769 DOI: 10.1016/j.actbio.2021.01.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 12/31/2022]
Abstract
Biotherapeutics have achieved global economic success due to their high specificity towards their drug targets, providing exceptional safety and efficiency. The ongoing shift away from small molecule drugs towards biotherapeutics heightens the need to further improve the pharmacokinetics of these biological drugs. Three pervasive obstacles that limit the therapeutic capacity of biotherapeutics are proteolytic degradation, circulating half-life, and the development of anti-drug antibodies. These challenges can culminate in limited efficiency and consequently warrant the need for higher drug doses and more frequent administration. We have explored the coupling of biotherapeutics to long-lived and biocompatible red blood cells (RBCs) to address limited pharmacokinetics. Butyrylcholinesterase (BChE), for example, provides prophylactic protection against organophosphate nerve agents (OPNAs), yet the short circulation life of the drug requires extraordinary doses. Herein, we report the rapid and tunable chemical engineering of BChE to RBC membranes to create a cell-based delivery system that retains the enzyme activity and enhances stability. In a three-step process that first pre-modifies BChE with a cell-reactive polymer chain, primes the cells for engineering, and then grafts the conjugates to the cells, we attached over 2 million BChE molecules to the surface of each RBC without diminishing the bioscavenging capacity of the enzyme. Critically, this membrane-engineering approach was cell-tolerated with minimal hemolysis observed. These results provide strong evidence for the ability of engineered RBCs to serve as an enhanced biotherapeutic delivery vehicle. STATEMENT OF SIGNIFICANCE: Organophosphate nerve agents (OPNAs) are one of the most lethal forms of chemical warfare. After exposure to OPNAs, a patient is given life-saving therapeutics, such as atropine and oxime. However, these drugs are limited, and the patient can still suffer from irreparable injuries. Given the toxicity of OPNAs, access to a prophylactic is vital. We have created an enhanced delivery system for prophylactic butyrylcholinesterase (BChE) by engineering this biotherapeutic to the red blood cell (RBC) surface. In three simple steps that first pre-modifies BChE with a cell-reactive polymer, primes the cells for engineering, and then grafts the conjugates to the cells, we attached over 2 million BChE molecules to a single RBC while retaining the enzyme's activity and enhancing its stability.
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6
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Nichols RH, Chambers JE. Reactivation of organophosphate-inhibited serum butyrylcholinesterase by novel substituted phenoxyalkyl pyridinium oximes and traditional oximes. Toxicology 2021; 452:152719. [PMID: 33592259 DOI: 10.1016/j.tox.2021.152719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/30/2021] [Accepted: 02/09/2021] [Indexed: 10/22/2022]
Abstract
Organophosphorus compounds (OPs) include nerve agents and insecticides that potently inhibit acetylcholinesterase (AChE), an essential enzyme found throughout the nervous system. High exposure levels to OPs lead to seizures, cardiac arrest, and death if left untreated. Oximes are a critical piece to the therapeutic regimen which remove the OP from the inhibited AChE and restore normal cholinergic function. The current oximes 2-PAM, MMB-4, TMB-4, HI-6, and obidoxime (OBD) have two drawbacks: lack of broad spectrum protection against multiple OP structures and poor brain penetration to protect against OP central neurotoxicity. An alternative strategy to enhance therapy is reactivation of serum butyrylcholinesterase (BChE). BChE is stoichiometrically inhibited by OPs with no apparent toxic result. Inhibition of BChE in the serum followed by reactivation could create a pseudo-catalytic scavenger allowing numerous regenerations of BChE to detoxify circulating OP molecules before they can reach target AChE. BChE in serum from rats, guinea pigs or humans was screened for the reactivation potential of our novel substituted phenoxyalkyl pyridinium oximes, plus 2-PAM, MMB-4, TMB-4, HI-6, and OBD (100μM) in vitro after inhibition by highly relevant surrogates of sarin, VX, and cyclosarin, and also DFP, and the insecticidal active metabolites paraoxon, phorate-oxon, and phorate-oxon sulfoxide. Novel oxime 15 demonstrated significant broad spectrum reactivation of OP-inhibited rat serum BChE while novel oxime 20 demonstrated significant broad spectrum reactivation of OP-inhibited human serum BChE. All tested oximes were poor reactivators of OP-inhibited guinea pig serum BChE. The bis-pyridinium oximes were poor BChE reactivators overall. BChE reactivation may be an additional mechanism to attenuate OP toxicity and contribute to therapeutic efficacy.
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Affiliation(s)
- Royce H Nichols
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762, United States
| | - Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, MS, 39762, United States.
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8
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Mirzaie V, Eslaminejad T, Babaei H, Nematollahi-Mahani SN. Enhancing the Butyrylcholinesterase Activity in HEK-293 Cell Line by Dual-Promoter Vector Decorated on Lipofectamine. DRUG DESIGN DEVELOPMENT AND THERAPY 2020; 14:3589-3599. [PMID: 32943846 PMCID: PMC7481294 DOI: 10.2147/dddt.s260419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/06/2020] [Indexed: 01/16/2023]
Abstract
Purpose Human butyrylcholinesterase (BChE) serves as a bio scavenger to counteract organophosphate poisoning. It is also a potential drug candidate in several therapeutic fields. Therefore, in the present study, we constructed a new dual-promoter plasmid consisting of Cytomegalovirus (CMV) and human elongation factor 1α (EF-1α) promoters and transfected that into HEK-293 cells using Lipofectamine to enhance the BChE secretion. Methods The new dual-promoter construction (pBudCE dual BChE) including two copies of the BChE gene was designed and transfected into cells by liposomal structures. The cloned plasmids were evaluated by enzyme digestion and gel electrophoresis analysis. Experimental groups were categorized into the cells transfected by pBudCE dual BChE (treatment), pCMV (positive control) vectors, and nontransfected cells (negative control). BChE gene expression was evaluated by qRT-PCR and the enzyme activity was assessed using modified Ellman’s method. The freeze-thaw process was carried out for analyzing the stability of the pBudCE dual BChE vector. Results Validation examination of the cloned plasmids confirmed the successful cloning process. The gene expression level and Ellman’s method value in pBudCE dual BChE was higher than the other groups. CMV promoter has also increased the enzyme activity, although the difference was not significant compared with the control group. Interestingly, freeze-thaw cycles followed by several passages did not affect the enzyme activity. Conclusion The designed construction with CMV and EF-1α promoters could increase BChE gene expression and the activity of the BChE enzyme in HEK-293 cell line. Large-scale production of BChE enzyme can be achieved by using dual-promoter plasmid construction compared to a single-promoter vector to be used in clinical trials.
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Affiliation(s)
- Vida Mirzaie
- Department of Anatomy, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Touba Eslaminejad
- Pharmaceutics Research Centre, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Homayoon Babaei
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Seyed Noureddin Nematollahi-Mahani
- Neuroscience Research Centre, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.,Afzal Research Institute (NGO), Kerman University of Medical Sciences, Kerman, Iran
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Rosenberg Y, Saxena A. Acetylcholinesterase inhibition resulting from exposure to inhaled OP can be prevented by pretreatment with BChE in both macaques and minipigs. Neuropharmacology 2020; 174:108150. [PMID: 32442543 PMCID: PMC7365266 DOI: 10.1016/j.neuropharm.2020.108150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/05/2020] [Accepted: 05/14/2020] [Indexed: 10/24/2022]
Abstract
More frequent and widespread nerve agent attacks highlight the need for efficacious pre- and post-exposure organophosphate (OP) counter-measures to protect military and civilian populations. Because of critical targeting of acetylcholinesterase (AChE) in the CNS by OPs, a pre-treatment candidate for preventing/reducing poisoning will be a broadly acting molecule that scavenges OPs in blood before they reach their physiological targets. Prophylactic human butyrylcholinesterase (HuBChE), the leading pretreatment candidate, has been shown to protect against multiple LD50's of nerve agents in rodents, macaques, and minipigs. This review describes the development of a HuBChE bioscavenger pretreatment from early proof-of-concept studies to pre-clinical studies with the native injectable enzyme and the development of aerosolized forms of recombinant enzyme, which can be delivered by inhalation nebulizer devices, to effect protection against inhaled OP nerve agents and insecticides. Early animal studies utilized parenteral exposure. However, lungs are the portal of entry for most volatile OP vapors and represent the major means of OP intoxication. In this regard, pretreat-ment with 7.5 mg/kg of HuBChE by IM injection protected minipigs against lethal sarin vapor and prevented AChE inhibition in the blood. This is similar to the five-day protection in macaques by an aerosolized rHuBChE using a nebulizer against aerosolized paraoxon (estimated to be an 8 mg/kg estimated human dose). Importantly, lethal inhaled doses of OP may be smaller relative to the same dose delivered by injection, thus reducing the protective HuBChE dose, while a combination of HuBChE and post-exposure oxime may prolong protection.
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Affiliation(s)
| | - Ashima Saxena
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
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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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Munir S, Habib R, Awan S, Bibi N, Tanveer A, Batool S, Nurulain SM. Biochemical Analysis and Association of Butyrylcholinesterase SNPs rs3495 and rs1803274 with Substance Abuse Disorder. J Mol Neurosci 2019; 67:445-455. [PMID: 30707402 DOI: 10.1007/s12031-018-1251-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 12/26/2018] [Indexed: 12/12/2022]
Abstract
Addiction is a complex mental and behavioral disorder that changes the neurochemistry and physiology of the brain. Genetics also plays a significant role in the pathophysiology of addiction. Butyrylcholinesterase (BChE), a cholinergic enzyme, has been implicated in the metabolism of various drugs, including cocaine, and an association between single-nucleotide polymorphisms (SNPs) of the butyrylcholinesterase gene (BCHE) and neuronal disorders has been reported. We report here the first investigation to be conducted on the status of BChE activity and the potential association of two BCHE gene SNPs, rs3495 (c.*189G > A) and rs1803274 (c.1699G>A, p.Ala567Thr, K-variant), with addiction vulnerability in heroin, hashish and polydrug users. Seventy-five individuals with an addiction to heroin, hashish and/or polydrug use were recruited to this study. BChE levels in the plasma were determined by Ellman's principle. SNPs were genotyped by standard procedures, followed by Sanger sequencing. Plasma BChE levels were found to be significantly higher (p ≤ 0.05) in addicts (mean ± standard error of the mean 0.031 ± 0.004 μmol/L/min; 95% confidence interval [CI] 0.024-0.038) than in non-addicts (controls) (0.014 ± 0.001 μmol/L/min; 95% CI 0.012-0.017). Statistical significant differences were also observed between the addicted cohorts. A statistically significant association for both SNPs (rs3495 and rs1803274) was not observed in addicted subjects tested in the dominant, recessive and allele genetic models, but trends of variations of the rs3495 risk G allele were noted. The authors conclude that BChE plays significant roles in addiction pathophysiology as increased BChE activity in blood samples obtained from the cohorts with addiction was evident. Further studies in this direction may provide novel approaches for the treatment of addiction, but studies with a larger sample size and different ethnic groups are warranted for broader conclusions to be drawn.
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Affiliation(s)
- Sadaf Munir
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Rabia Habib
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan.
| | - Sliha Awan
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Nazia Bibi
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Arooj Tanveer
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Sajida Batool
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan
| | - Syed M Nurulain
- Department of Biosciences, Functional Proteomics and Genomics Lab, COMSATS University Islamabad, Islamabad, Pakistan.
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Characterization of butyrylcholinesterase from porcine milk. Arch Biochem Biophys 2018; 652:38-49. [PMID: 29908755 DOI: 10.1016/j.abb.2018.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 12/22/2022]
Abstract
Human butyrylcholinesterase (HuBChE) is under development for use as a pretreatment antidote against nerve agent toxicity. Animals are used to evaluate the efficacy of HuBChE for protection against organophosphorus nerve agents. Pharmacokinetic studies of HuBChE in minipigs showed a mean residence time of 267 h, similar to the half-life of HuBChE in humans, suggesting a high degree of similarity between BChE from 2 sources. Our aim was to compare the biochemical properties of PoBChE purified from porcine milk to HuBChE purified from human plasma. PoBChE hydrolyzed acetylthiocholine slightly faster than butyrylthiocholine, but was sensitive to BChE-specific inhibitors. PoBChE was 50-fold less sensitive to inhibition by DFP than HuBChE and 5-fold slower to reactivate in the presence of 2-PAM. The amino acid sequence of PoBChE determined by liquid chromatography tandem mass spectrometry was 91% identical to HuBChE. Monoclonal antibodies 11D8, mAb2, and 3E8 (HAH 002) recognized both PoBChE and HuBChE. Assembly of 4 identical subunits into tetramers occurred by noncovalent interaction with polyproline-rich peptides in PoBChE as well as in HuBChE, though the set of polyproline-rich peptides in milk-derived PoBChE was different from the set in plasma-derived HuBChE tetramers. It was concluded that the esterase isolated from porcine milk is PoBChE.
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Bonichon M, Valbi V, Combès A, Desoubries C, Bossée A, Pichon V. Online coupling of immunoextraction, digestion, and microliquid chromatography-tandem mass spectrometry for the analysis of sarin and soman-butyrylcholinesterase adducts in human plasma. Anal Bioanal Chem 2017; 410:1039-1051. [PMID: 28971225 DOI: 10.1007/s00216-017-0640-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/16/2017] [Accepted: 09/14/2017] [Indexed: 12/13/2022]
Abstract
Organophosphorus nerve agent (OPNA) adducts formed with human butyrylcholinesterase (HuBuChE) can be used as biomarker of OPNA exposure. Indeed, intoxication by OPNAs can be confirmed by the LC/MS2 analysis of a specific HuBuChE nonapeptide on which OPNAs covalently bind. A fast, selective, and highly sensitive online method was developed to detect sarin and soman adducts in plasma, including immunoextraction by anti-HuBuChE antibodies, pepsin digestion on immobilized enzyme reactors (IMER), and microLC/MS2 analysis of the OPNA adducts. The potential of three different monoclonal antibodies, covalently grafted on sepharose, was compared for the extraction of HuBuChE. The online method developed with the most promising antibodies allowed the extraction of up to 100% of HuBuChE contained in plasma and the digestion of 45% of it in less than 40 min. Moreover, OPNA-HuBuChE adducts, aged OPNA adducts, and unadducted HuBuChE could be detected (with S/N > 2000), even in plasma spiked with a low concentration of OPNA (10 ng mL-1). Finally, the potential of this method was compared to approaches involving other affinity sorbents, already described for HuBuChE extraction. Graphical abstract Online coupling of immunoextraction, digestion, and microliquid chromatography-tandem mass spectrometry for the analysis of organophosphorous nerve agent adducts formed with human butyrylcholinesterase.
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Affiliation(s)
- Maud Bonichon
- Department of Analytical, Bioanalytical Sciences and Miniaturization (LSABM), UMR CNRS-ESPCI Paris, CBI 8231, PSL Research University, ESPCI Paris, 10 rue Vauquelin, Paris, France
| | - Valentina Valbi
- Department of Analytical, Bioanalytical Sciences and Miniaturization (LSABM), UMR CNRS-ESPCI Paris, CBI 8231, PSL Research University, ESPCI Paris, 10 rue Vauquelin, Paris, France
| | - Audrey Combès
- Department of Analytical, Bioanalytical Sciences and Miniaturization (LSABM), UMR CNRS-ESPCI Paris, CBI 8231, PSL Research University, ESPCI Paris, 10 rue Vauquelin, Paris, France
| | | | - Anne Bossée
- DGA, CBRN Defence, 5 rue Lavoisier, Vert-le-Petit, France
| | - Valérie Pichon
- Department of Analytical, Bioanalytical Sciences and Miniaturization (LSABM), UMR CNRS-ESPCI Paris, CBI 8231, PSL Research University, ESPCI Paris, 10 rue Vauquelin, Paris, France. .,UPMC, Sorbonne University, 4 Place Jussieu, Paris, France.
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14
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Polyionic complexes of butyrylcholinesterase and poly-l-lysine-g-poly(ethylene glycol): Comparative kinetics of catalysis and inhibition and in vitro inactivation by proteases and heat. Chem Biol Interact 2017; 275:86-94. [DOI: 10.1016/j.cbi.2017.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/27/2017] [Accepted: 07/25/2017] [Indexed: 01/11/2023]
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15
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Reed BA, Sabourin CL, Lenz DE. Human butyrylcholinesterase efficacy against nerve agent exposure. J Biochem Mol Toxicol 2017; 31. [DOI: 10.1002/jbt.21886] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/23/2016] [Accepted: 11/28/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Beth A. Reed
- Battelle Memorial Institute; Columbus OH 43201-2693 USA
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16
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Yang SH, Sun Q, Xiong H, Liu SY, Moosavi B, Yang WC, Yang GF. Discovery of a butyrylcholinesterase-specific probe via a structure-based design strategy. Chem Commun (Camb) 2017; 53:3952-3955. [DOI: 10.1039/c7cc00577f] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We report herein the structure-based design and application of a fluorogenic butyrylcholinesterase probe that could discriminate butyrylcholinesterase from acetylcholinesterase.
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Affiliation(s)
- Shu-Hou Yang
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
| | - Qi Sun
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
| | - Hao Xiong
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
| | - Shi-Yu Liu
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
| | - Behrooz Moosavi
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
| | - Wen-Chao Yang
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
| | - Guang-Fu Yang
- Key Laboratory of Pesticide and Chemical Biology
- Ministry of Education
- College of Chemistry
- Central China Normal University
- Wuhan 430079
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17
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Sawatzky E, Al-Momani E, Kobayashi R, Higuchi T, Samnick S, Decker M. A Novel Way To Radiolabel Human Butyrylcholinesterase for Positron Emission Tomography through Irreversible Transfer of the Radiolabeled Moiety. ChemMedChem 2016; 11:1540-50. [DOI: 10.1002/cmdc.201600223] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/30/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Edgar Sawatzky
- Pharmaceutical and Medicinal Chemistry; Institute of Pharmacy and Food Chemistry; Julius Maximilian University Würzburg; Am Hubland 97074 Würzburg Germany
| | - Ehab Al-Momani
- Experimental Nuclear Medicine; Center of Inner Medicine; University Hospital Würzburg; OberdürrbacherStrasse 6 97080 Würzburg Germany
| | - Ryohei Kobayashi
- Experimental Nuclear Medicine; Center of Inner Medicine; University Hospital Würzburg; OberdürrbacherStrasse 6 97080 Würzburg Germany
| | - Takahiro Higuchi
- Experimental Nuclear Medicine; Center of Inner Medicine; University Hospital Würzburg; OberdürrbacherStrasse 6 97080 Würzburg Germany
| | - Samuel Samnick
- Experimental Nuclear Medicine; Center of Inner Medicine; University Hospital Würzburg; OberdürrbacherStrasse 6 97080 Würzburg Germany
| | - Michael Decker
- Pharmaceutical and Medicinal Chemistry; Institute of Pharmacy and Food Chemistry; Julius Maximilian University Würzburg; Am Hubland 97074 Würzburg Germany
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18
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Saxena A, Hastings NB, Sun W, Dabisch PA, Hulet SW, Jakubowski EM, Mioduszewski RJ, Doctor BP. Prophylaxis with human serum butyrylcholinesterase protects Göttingen minipigs exposed to a lethal high-dose of sarin vapor. Chem Biol Interact 2015; 238:161-9. [PMID: 26145887 DOI: 10.1016/j.cbi.2015.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/02/2015] [Indexed: 11/17/2022]
Abstract
Serum-derived human butyrylcholinesterase (Hu BChE) is a stoichiometric bioscavenger that is being developed as a potential prophylactic nerve agent countermeasure. Previously, we reported the prophylactic efficacy of Hu BChE in Göttingen minipigs against a whole-body exposure to 4.1mg/m(3) of sarin (GB) vapor, which produced lethality over 60min. Since the toxicity of nerve agent is concentration-dependent, in the present study, we investigated the toxic effects of an almost 3-fold higher rate of GB vapor exposure and the ability of Hu BChE to protect minipigs against this exposure. Male minipigs were subjected to: (1) air exposure; (2) GB vapor exposure; or (3) pretreatment with 7.5mg/kg of Hu BChE by i.m. injection, 24h prior to whole-body exposure to 11.4mg/m(3) of GB vapor for 10min. Electrocardiogram, electroencephalogram, and pupil size were monitored throughout exposure. Blood drawn before and throughout exposure was analyzed for blood gases, electrolytes, metabolites, acetylcholinesterase and BChE activities, and amount of GB bound to red blood cells and plasma. A novel finding was that saline-treated animals exposed to GB vapor did not develop any seizures, but manifested a variety of cardiac and whole blood toxic signs and rapidly died due to respiratory failure. Strikingly, pre-treatment with 7.5mg/kg of Hu BChE not only prevented lethality, but also avoided all cardiac toxic signs manifested in the non-treated cohort. Thus, Hu BChE alone can serve as an effective prophylactic countermeasure versus a lethal high-dose exposure to GB vapor.
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Affiliation(s)
- Ashima Saxena
- Division of Biochemistry, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States.
| | - Nicholas B Hastings
- Division of Biochemistry, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States
| | - Wei Sun
- Division of Biochemistry, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States
| | - Paul A Dabisch
- Operational Toxicology Team, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD 21010, United States
| | - Stanley W Hulet
- Operational Toxicology Team, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD 21010, United States
| | - Edward M Jakubowski
- Operational Toxicology Team, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD 21010, United States
| | - Robert J Mioduszewski
- Operational Toxicology Team, Edgewood Chemical Biological Center, Aberdeen Proving Ground, MD 21010, United States
| | - Bhupendra P Doctor
- Division of Biochemistry, Walter Reed Army Institute of Research, Silver Spring, MD 20910, United States
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19
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Kochkina EG, Plesneva SA, Zhuravin IA, Turner AJ, Nalivaeva NN. Effect of hypoxia on cholinesterase activity in rat sensorimotor cortex. J EVOL BIOCHEM PHYS+ 2015. [DOI: 10.1134/s0022093015020039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Mirfazaeli H, Nikfar S, Rezvanfar MA, Abdollahi M. Efficacy of Plasma Transfusion in Acute Human Organophosphorus Poisoning: A Systematic Review and Meta-analysis. INT J PHARMACOL 2014. [DOI: 10.3923/ijp.2014.299.306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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21
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Protection against paraoxon toxicity by an intravenous pretreatment with polyethylene-glycol-conjugated recombinant butyrylcholinesterase in macaques. Chem Biol Interact 2013; 210:20-5. [PMID: 24384224 DOI: 10.1016/j.cbi.2013.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 11/27/2013] [Accepted: 12/20/2013] [Indexed: 11/23/2022]
Abstract
Recombinant (r) butyrylcholinesterase (rBChE) produced in CHO cells is being developed as a prophylactic countermeasure against neurotoxicity resulting from exposure to organophosphates (OPs) in the form of pesticides and nerve agents. To evaluate the efficacy of a parenteral pretreatment, a PEGylated macaque (Ma) form of rBChE was administered into homologous animals to ensure good plasma retention without immunogenicity. Thus, macaques were administered PEG-rMaBChE at either 5 or 7mg/kg intravenously (i.v.) and exposed subcutaneously to 12μg/kg of the potent pesticide paraoxon (Px) at 1h or at 1 and 72h, respectively. Protection was measured by the ability of rBChE prophylaxis to prevent the inhibition of circulating acetylcholinesterase on red blood cells (RBC-AChE). In rBChE-pretreated animals, no inhibition of RBC-AChE activity after the first Px exposure and only a 10-20% reduction after the second exposure were observed as compared to a 75% RBC-AChE inhibition usually obtained without pretreatment. In addition, these studies raised other interesting issues. The lipophilic nature of Px, appears to result in early and transient inhibition of RBC-AChE as a result of transfer of OP bound to RBC even in BChE-pretreated animals. The protection by a single injection of rBChE against two administrations of Px represents the first example of protection by an i.v. rBChE pretreatment against a pesticide such as Px and bodes well for a parenteral rHuBChE pretreatment as an OP countermeasure in humans.
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22
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Naik RS, Pattabiraman N, Patel KA, Doctor BP, Saxena A. Amino acid residues at the N- and C-termini are essential for the folding of active human butyrylcholinesterase polypeptide. Chem Biol Interact 2013; 203:24-9. [PMID: 23044488 DOI: 10.1016/j.cbi.2012.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/06/2012] [Accepted: 09/10/2012] [Indexed: 11/18/2022]
Abstract
Human serum butyrylcholinesterase (HuBChE) is currently the most suitable bioscavenger for the prophylaxis of highly toxic organophosphate (OP) nerve agents. A dose of 200mg of HuBChE is envisioned as a prophylactic treatment that can protect humans from an exposure of up to 2 × LD50 of soman. The limited availability and administration of multiple doses of this stoichiometric bioscavenger make this pretreatment difficult. Thus, the goal of this study was to produce a smaller enzymatically active HuBChE polypeptide (HBP) that could bind to nerve agents with high affinity thereby reducing the dose of enzyme. Studies have indicated that the three-dimensional structure and the domains of HuBChE (acyl pocket, lip of the active center gorge, and the anionic substrate-binding domain) that are critical for the binding of substrate are also essential for the selectivity and binding of inhibitors including OPs. Therefore, we designed three HBPs by deleting some N- and C-terminal residues of HuBChE by maintaining the folds of the active site core that includes the three active site residues (S198, E325, and H438). HBP-4 that lacks 45 residues from C-terminus but known to have BChE activity was used as a control. The cDNAs for the HBPs containing signal sequences were synthesized, cloned into different mammalian expression vectors, and recombinant polypeptides were transiently expressed in different cell lines. No BChE activity was detected in the culture media of cells transfected with any of the newly designed HBPs, and the inactive polypeptides remained inside the cells. Only enzymatically active HBP-4 was secreted into the culture medium. These results suggest that residues at the N- and C-termini are required for the folding and/or maintenance of HBP into an active stable, conformation.
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Affiliation(s)
- Ramachandra S Naik
- Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
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23
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Geyer BC, Larrimore KE, Kilbourne J, Kannan L, Mor TS. Reversal of succinylcholine induced apnea with an organophosphate scavenging recombinant butyrylcholinesterase. PLoS One 2013; 8:e59159. [PMID: 23536865 PMCID: PMC3594170 DOI: 10.1371/journal.pone.0059159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/12/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Concerns about the safety of paralytics such as succinylcholine to facilitate endotracheal intubation limit their use in prehospital and emergency department settings. The ability to rapidly reverse paralysis and restore respiratory drive would increase the safety margin of an agent, thus permitting the pursuit of alternative intubation strategies. In particular, patients who carry genetic or acquired deficiency of butyrylcholinesterase, the serum enzyme responsible for succinylcholine hydrolysis, are susceptible to succinylcholine-induced apnea, which manifests as paralysis, lasting hours beyond the normally brief half-life of succinylcholine. We hypothesized that intravenous administration of plant-derived recombinant BChE, which also prevents mortality in nerve agent poisoning, would rapidly reverse the effects of succinylcholine. METHODS Recombinant butyrylcholinesterase was produced in transgenic plants and purified. Further analysis involved murine and guinea pig models of succinylcholine toxicity. Animals were treated with lethal and sublethal doses of succinylcholine followed by administration of butyrylcholinesterase or vehicle. In both animal models vital signs and overall survival at specified intervals post succinylcholine administration were assessed. RESULTS Purified plant-derived recombinant human butyrylcholinesterase can hydrolyze succinylcholine in vitro. Challenge of mice with an LD100 of succinylcholine followed by BChE administration resulted in complete prevention of respiratory inhibition and concomitant mortality. Furthermore, experiments in symptomatic guinea pigs demonstrated extremely rapid succinylcholine detoxification with complete amelioration of symptoms and no apparent complications. CONCLUSIONS Recombinant plant-derived butyrylcholinesterase was capable of counteracting and reversing apnea in two complementary models of lethal succinylcholine toxicity, completely preventing mortality. This study of a protein antidote validates the feasibility of protection and treatment of overdose from succinylcholine as well as other biologically active butyrylcholinesterase substrates.
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Affiliation(s)
- Brian C. Geyer
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Katherine E. Larrimore
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Jacquelyn Kilbourne
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Latha Kannan
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Tsafrir S. Mor
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
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24
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Sun W, Luo C, Tipparaju P, Doctor BP, Saxena A. Effect of polyethylene glycol conjugation on the circulatory stability of plasma-derived human butyrylcholinesterase in mice. Chem Biol Interact 2013; 203:172-6. [DOI: 10.1016/j.cbi.2012.11.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 11/26/2012] [Accepted: 11/28/2012] [Indexed: 10/27/2022]
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25
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Saxena A, Sun W, Dabisch PA, Hulet SW, Hastings NB, Jakubowski EM, Mioduszewski RJ, Doctor BP. Pretreatment with human serum butyrylcholinesterase alone prevents cardiac abnormalities, seizures, and death in Göttingen minipigs exposed to sarin vapor. Biochem Pharmacol 2011; 82:1984-93. [DOI: 10.1016/j.bcp.2011.09.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/09/2011] [Accepted: 09/12/2011] [Indexed: 11/17/2022]
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26
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Wang L, Du D, Lu D, Lin CT, Smith JN, Timchalk C, Liu F, Wang J, Lin Y. Enzyme-linked immunosorbent assay for detection of organophosphorylated butyrylcholinesterase: a biomarker of exposure to organophosphate agents. Anal Chim Acta 2011; 693:1-6. [PMID: 21504805 DOI: 10.1016/j.aca.2011.03.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/04/2011] [Accepted: 03/06/2011] [Indexed: 01/13/2023]
Abstract
A sandwich enzyme-linked immunosorbent assay (sELISA) has been developed for detection of organophosphorylated butyrylcholinesterase (OP-BChE), a potential biomarker for human exposure to organophosphate insecticides and nerve agents. A pair of antibodies specific to OP-BChE adduct were identified through systematic screening of several anti BChE antibodies (anti-BChE) and anti-phosphoserine antibodies (anti-P(ser)) from different sources. The selected anti-BChE (set as capture antibody) antibodies recognize both phosphorylated and nonphosphorylated BChE. These antibodies can therefore be used to capture both BChE and OP-BChE from the sample matrices. The anti-P(ser) (set as detecting antibody) was used to recognize the OP moiety of OP-BChE adducts. With the combination of the selected antibody pair, several key parameters (such as the concentration of anti-BChE and anti-P(ser), and the blocking agent) were optimized to enhance the sensitivity and selectivity of the sELISA. Under the optimal conditions, the sELISA has shown a wide linear range from 0.03 nM to 30 nM, with a detection limit of 0.03 nM. Furthermore, the sELISA was successfully applied to detect OP-BChE using in vitro biological samples such as rat plasma spiked with OP-BChE with excellent adduct recovery (z>99%). These results demonstrate that this novel approach holds great promise to develop an ELISA kit and offers a simple and cost-effective tool for screening/evaluating exposure to organophosphate insecticides and nerve agents.
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Affiliation(s)
- Limin Wang
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, China
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27
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Geyer BC, Kannan L, Garnaud PE, Broomfield CA, Cadieux CL, Cherni I, Hodgins SM, Kasten SA, Kelley K, Kilbourne J, Oliver ZP, Otto TC, Puffenberger I, Reeves TE, Robbins N, Woods RR, Soreq H, Lenz DE, Cerasoli DM, Mor TS. Plant-derived human butyrylcholinesterase, but not an organophosphorous-compound hydrolyzing variant thereof, protects rodents against nerve agents. Proc Natl Acad Sci U S A 2010; 107:20251-6. [PMID: 21059932 PMCID: PMC2996644 DOI: 10.1073/pnas.1009021107] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The concept of using cholinesterase bioscavengers for prophylaxis against organophosphorous nerve agents and pesticides has progressed from the bench to clinical trial. However, the supply of the native human proteins is either limited (e.g., plasma-derived butyrylcholinesterase and erythrocytic acetylcholinesterase) or nonexisting (synaptic acetylcholinesterase). Here we identify a unique form of recombinant human butyrylcholinesterase that mimics the native enzyme assembly into tetramers; this form provides extended effective pharmacokinetics that is significantly enhanced by polyethylene glycol conjugation. We further demonstrate that this enzyme (but not a G117H/E197Q organophosphorus acid anhydride hydrolase catalytic variant) can prevent morbidity and mortality associated with organophosphorous nerve agent and pesticide exposure of animal subjects of two model species.
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Affiliation(s)
- Brian C. Geyer
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Latha Kannan
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Pierre-Emmanuel Garnaud
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Clarence A. Broomfield
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - C. Linn Cadieux
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Irene Cherni
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Sean M. Hodgins
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Shane A. Kasten
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Karli Kelley
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Jacquelyn Kilbourne
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Zeke P. Oliver
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Tamara C. Otto
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Ian Puffenberger
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Tony E. Reeves
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Neil Robbins
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Ryan R. Woods
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
| | - Hermona Soreq
- Silberman Life Sciences Institute, Edmond J. Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel 91904
| | - David E. Lenz
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Douglas M. Cerasoli
- Research Division, Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400; and
| | - Tsafrir S. Mor
- School of Life Sciences and Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501
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Saxena A, Sun W, Fedorko JM, Koplovitz I, Doctor BP. Prophylaxis with human serum butyrylcholinesterase protects guinea pigs exposed to multiple lethal doses of soman or VX. Biochem Pharmacol 2010; 81:164-9. [PMID: 20846507 DOI: 10.1016/j.bcp.2010.09.007] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 09/03/2010] [Accepted: 09/07/2010] [Indexed: 11/26/2022]
Abstract
Human serum butyrylcholinesterase (Hu BChE) is currently under advanced development as a bioscavenger for the prophylaxis of organophosphorus (OP) nerve agent toxicity in humans. It is estimated that a dose of 200mg will be required to protect a human against 2×LD(50) of soman. To provide data for initiating an investigational new drug application for the use of this enzyme as a bioscavenger in humans, we purified enzyme from Cohn fraction IV-4 paste and initiated safety and efficacy evaluations in mice, guinea pigs, and non-human primates. In mice, we demonstrated that a single dose of enzyme that is 30 times the therapeutic dose circulated in blood for at least four days and did not cause any clinical pathology in these animals. In this study, we report the results of safety and efficacy evaluations conducted in guinea pigs. Various doses of Hu BChE delivered by i.m. injections peaked at ∼24h and had a mean residence time of 78-103h. Hu BChE did not exhibit any toxicity in guinea pigs as measured by general observation, serum chemistry, hematology, and gross and histological tissue changes. Efficacy evaluations showed that Hu BChE protected guinea pigs from an exposure of 5.5×LD(50) of soman or 8×LD(50) of VX. These results provide convincing data for the development of Hu BChE as a bioscavenger that can protect humans against all OP nerve agents.
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Affiliation(s)
- Ashima Saxena
- Division of Biochemistry, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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Saxena A, Tipparaju P, Luo C, Doctor BP. Pilot-scale production of human serum butyrylcholinesterase suitable for use as a bioscavenger against nerve agent toxicity. Process Biochem 2010. [DOI: 10.1016/j.procbio.2010.04.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Sun W, Luo C, Naik RS, Doctor BP, Saxena A. Pharmacokinetics and immunologic consequences of repeated administrations of purified heterologous and homologous butyrylcholinesterase in mice. Life Sci 2009; 85:657-61. [PMID: 19772863 DOI: 10.1016/j.lfs.2009.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 08/27/2009] [Accepted: 09/10/2009] [Indexed: 10/20/2022]
Abstract
AIM To assess the consequences of repeated administrations of purified human serum butyrylcholinesterase (Hu BChE) and mouse serum (Mo) BChE into mice. MAIN METHODS Purified Hu BChE and Mo BChE isolated from the sera of CD-1 mice were administered into Balb/c or CD-1 mice. The enzymes were delivered by i.m. injections of approximately 100U (0.15mg) on day 1 and on day 28, respectively. The effects of two injections were monitored by following blood BChE and anti-BChE IgG levels. KEY FINDINGS Hu BChE displayed a mean residence time (MRT) of 50h, and an area under the curve (AUC) of 1220U/ml.h in Balb/c or CD-1 mice. Mo BChE exhibited an MRT of 78h and an AUC of 1815U/ml.h in Balb/c mice; the AUC increased to 2504U/ml.h in CD-1 mice. A second injection of Hu BChE in both strains exhibited a marked reduction in circulatory stability. The circulatory stability of the second injection of Mo BChE was reduced in Balb/c mice, but was almost identical to the first injection in CD-1 mice. Consistent with these observations, circulating anti-BChE IgGs were observed in mice injected with Hu BChE; low levels of anti-BChE IgGs were observed only in Balb/c mice injected with Mo BChE. No antibody response was detected in CD-1 mice following either injection of homologous Mo BChE. SIGNIFICANCE The identical pharmacokinetic profiles and the absence of an immunologic response following a second administration of homologous BChE support the development of Hu BChE as a detoxifying drug in humans.
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Affiliation(s)
- Wei Sun
- Division of Bacterial and Rickettsial Diseases, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA
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Woods RR, Geyer BC, Mor TS. Hairy-root organ cultures for the production of human acetylcholinesterase. BMC Biotechnol 2008; 8:95. [PMID: 19105816 PMCID: PMC2648960 DOI: 10.1186/1472-6750-8-95] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 12/23/2008] [Indexed: 12/16/2023] Open
Abstract
BACKGROUND Human cholinesterases can be used as a bioscavenger of organophosphate toxins used as pesticides and chemical warfare nerve agents. The practicality of this approach depends on the availability of the human enzymes, but because of inherent supply and regulatory constraints, a suitable production system is yet to be identified. RESULTS As a promising alternative, we report the creation of "hairy root" organ cultures derived via Agrobacterium rhizogenes-mediated transformation from human acetylcholinesterase-expressing transgenic Nicotiana benthamiana plants. Acetylcholinesterase-expressing hairy root cultures had a slower growth rate, reached to the stationary phase faster and grew to lower maximal densities as compared to wild type control cultures. Acetylcholinesterase accumulated to levels of up to 3.3% of total soluble protein, ~3 fold higher than the expression level observed in the parental plant. The enzyme was purified to electrophoretic homogeneity. Enzymatic properties were nearly identical to those of the transgenic plant-derived enzyme as well as to those of mammalian cell culture derived enzyme. Pharmacokinetic properties of the hairy-root culture derived enzyme demonstrated a biphasic clearing profile. We demonstrate that master banking of plant material is possible by storage at 4 degrees C for up to 5 months. CONCLUSION Our results support the feasibility of using plant organ cultures as a successful alternative to traditional transgenic plant and mammalian cell culture technologies.
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Affiliation(s)
- Ryan R Woods
- School of Life Sciences and The Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Brian C Geyer
- School of Life Sciences and The Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Tsafrir S Mor
- School of Life Sciences and The Biodesign Institute, P.O. Box 874501, Arizona State University, Tempe, AZ 85287-4501, USA
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Saxena A, Sun W, Dabisch PA, Hulet SW, Hastings NB, Jakubowski EM, Mioduszewski RJ, Doctor BP. Efficacy of human serum butyrylcholinesterase against sarin vapor. Chem Biol Interact 2008; 175:267-72. [PMID: 18597747 DOI: 10.1016/j.cbi.2008.05.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 05/13/2008] [Accepted: 05/14/2008] [Indexed: 10/22/2022]
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Saxena A, Luo C, Doctor BP. Developing procedures for the large-scale purification of human serum butyrylcholinesterase. Protein Expr Purif 2008; 61:191-6. [PMID: 18602477 DOI: 10.1016/j.pep.2008.05.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Accepted: 05/27/2008] [Indexed: 11/29/2022]
Abstract
Human serum butyrylcholinesterase (Hu BChE) is the most viable candidate for the prophylactic treatment of organophosphate poisoning. A dose of 200 mg/70 kg is predicted to protect humans against 2x LD(50) of soman. Therefore, the aim of this study was to develop procedures for the purification of gram quantities of this enzyme from outdated human plasma or Cohn Fraction IV-4. The purification of Hu BChE was accomplished by batch adsorption on procainamide-Sepharose-CL-4B affinity gel followed by ion-exchange chromatography on a DEAE-Sepharose column. For the purification of enzyme from Cohn Fraction IV-4, it was resuspended in 25 mM sodium phosphate buffer, pH 8.0, and fat was removed by decantation, prior to batch adsorption on procainamide-Sepharose gel. In both cases, the procainamide gel was thoroughly washed with 25 mM sodium phosphate buffer, pH 8.0, containing 0.05 M NaCl, and the enzyme was eluted with the same buffer containing 0.1 M procainamide. The enzyme was dialyzed and the pH was adjusted to 4.0 before loading on the DEAE column equilibrated in sodium acetate buffer, pH 4.0. The column was thoroughly washed with 25 mM sodium phosphate buffer, pH 8.0 containing 0.05 M NaCl before elution with a gradient of 0.05-0.2M NaCl in the same buffer. The purity of the enzyme following these steps ranged from 20% to 40%. The purity of the enzyme increased to >90% by chromatography on an analytical procainamide affinity column. Results show that Cohn Fraction IV-4 is a much better source than plasma for the large-scale isolation of purified Hu BChE.
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Affiliation(s)
- Ashima Saxena
- Division of Biochemistry, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA.
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Masson P, Nachon F, Broomfield CA, Lenz DE, Verdier L, Schopfer LM, Lockridge O. A collaborative endeavor to design cholinesterase-based catalytic scavengers against toxic organophosphorus esters. Chem Biol Interact 2008; 175:273-80. [PMID: 18508040 DOI: 10.1016/j.cbi.2008.04.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 03/18/2008] [Accepted: 04/02/2008] [Indexed: 10/22/2022]
Abstract
Wild-type human butyrylcholinesterase (BuChE) has proven to be an efficient bioscavenger for protection against nerve agent toxicity. Human acetylcholinesterase (AChE) has a similar potential. A limitation to their usefulness is that both cholinesterases (ChEs) react stoichiometrically with organophosphosphorus (OP) esters. Because OPs can be regarded as pseudo-substrates for which the dephosphylation rate constant is almost zero, several strategies have been attempted to promote the dephosphylation reaction. Oxime-mediated reactivation of phosphylated ChEs generates a turnover, but it is too slow to make pseudo-catalytic scavengers of pharmacological interest. Alternatively, it was hypothesized that ChEs could be converted into OP hydrolases by using rational site-directed mutagenesis based upon the crystal structure of ChEs. The idea was to introduce a nucleophile into the oxyanion hole, at an appropriate position to promote hydrolysis of the phospho-serine bond via a base catalysis mechanism. Such mutants, if they showed the desired catalytic and pharmacokinetic properties, could be used as catalytic scavengers. The first mutant of human BuChE that was capable of hydrolyzing OPs was G117H. It had a slow rate. Crystallographic study of the G117H mutant showed that hydrolysis likely occurs by activation of a water molecule rather than direct nucleophilic attack by H117. Numerous BuChE mutants were made later, but none of them was better than the G117H mutant at hydrolyzing OPs, with the exception of soman. Soman aged too rapidly to be hydrolyzed by G117H. Hydrolysis was however accomplished with the double mutant G117H/E197Q, which did not age after phosphonylation with soman. Multiple mutations in the active center of human and Bungarus AChE led to enzymes displaying low catalytic activity towards OPs and unwanted kinetic complexities. A new generation of human AChE mutants has been designed with the assistance of molecular modelling and computational methods. According to the putative water-activation mechanism of G117H BChE, a new histidine/aspartate dyad was introduced into the active center of human AChE at the optimum location for hydrolysis of the OP adduct. Additional mutations were made for optimizing activity of the new dyad. It is anticipated that these new mutants will have OP hydrolase activity.
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Affiliation(s)
- Patrick Masson
- Toxicology Department, Enzymology Unit, Centre de Recherches du Service de Santé des Armées, La Tronche Cedex, France.
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Evron T, Geyer BC, Cherni I, Muralidharan M, Kilbourne J, Fletcher SP, Soreq H, Mor TS. Plant-derived human acetylcholinesterase-R provides protection from lethal organophosphate poisoning and its chronic aftermath. FASEB J 2007; 21:2961-9. [PMID: 17475919 PMCID: PMC2766558 DOI: 10.1096/fj.07-8112com] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Therapeutically valuable proteins are often rare and/or unstable in their natural context, calling for production solutions in heterologous systems. A relevant example is that of the stress-induced, normally rare, and naturally unstable "read-through" human acetylcholinesterase variant, AChE-R. AChE-R shares its active site with the synaptic AChE-S variant, which is the target of poisonous organophosphate anticholinesterase insecticides such as the parathion metabolite paraoxon. Inherent AChE-R overproduction under organophosphate intoxication confers both short-term protection (as a bioscavenger) and long-term neuromuscular damages (as a regulator). Here we report the purification, characterization, and testing of human, endoplasmic reticulum-retained AChE-R(ER) produced from plant-optimized cDNA in Nicotiana benthamiana plants. AChE-R(ER) purified to homogeneity showed indistinguishable biochemical properties, with IC50 = 10(-7) M for the organophosphate paraoxon, similar to mammalian cell culture-derived AChE. In vivo titration showed dose-dependent protection by intravenously injected AChE-R(ER) of FVB/N male mice challenged with a lethal dose of paraoxon, with complete elimination of short-term clinical symptoms at near molar equivalence. By 10 days postexposure, AChE-R prophylaxis markedly limited postexposure increases in plasma murine AChE-R levels while minimizing the organophosphate-induced neuromuscular junction dismorphology. Our findings present plant-produced AChE-R(ER) as a bimodal agent, conferring both short- and long-term protection from organophosphate intoxication.
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Affiliation(s)
- Tama Evron
- The Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Brian C. Geyer
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Irene Cherni
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Mrinalini Muralidharan
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Jacquelyn Kilbourne
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Samuel P. Fletcher
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Hermona Soreq
- The Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tsafrir S. Mor
- School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
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Yuan J, Yin J, Wang E. Characterization of procaine metabolism as probe for the butyrylcholinesterase enzyme investigation by simultaneous determination of procaine and its metabolite using capillary electrophoresis with electrochemiluminescence detection. J Chromatogr A 2007; 1154:368-72. [PMID: 17507024 DOI: 10.1016/j.chroma.2007.02.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2006] [Revised: 02/02/2007] [Accepted: 02/07/2007] [Indexed: 11/20/2022]
Abstract
Capillary electrophoresis with electrochemiluminescene detection was used to characterize procaine hydrolysis as a probe for butyrylcholinesterase by in vitro procaine metabolism in plasma with butyrylcholinesterase acting as bioscavenger. Procaine and its metabolite N,N-diethylethanolamine were separated at 16 kV and then detected at 1.25 V in the presence of 5.0 mM Ru(bpy)(3)2+, with the detection limits of 2.4x10(-7) and 2.0x10(-8) mol/L (S/N=3), respectively. The Michaelis constant Km value was 1.73x10(-4) mol/L and the maximum velocity Vmax was 1.62x10(-6) mol/L/min. Acetylcholine bromide and choline chloride presented inhibition effects on the enzymatic cleavage of procaine, with the 50% inhibition concentration (IC50) of 6.24x10(-3) and 2.94x10(-4) mol/L.
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Affiliation(s)
- Jipei Yuan
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of the Chinese Acadamy of Sciences, Changchun, Jilin 130022, China
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Multi-site inhibition of human plasma cholinesterase by cationic phenoxazine and phenothiazine dyes. Arch Biochem Biophys 2007; 461:294-8. [PMID: 17428437 DOI: 10.1016/j.abb.2007.02.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Revised: 02/23/2007] [Accepted: 02/23/2007] [Indexed: 11/20/2022]
Abstract
Two cationic phenoxazine dyes, meldola blue (MB) and nile blue (NB), and the structurally related phenothiazine, methylene blue (MethB), were found to act as complex inhibitors of human plasma cholinesterase (butyrylcholinesterase, BChE). Studied at 25 degrees C, in 100mM MOPS buffer (pH 8.0), with butyrylthiocholine as substrate, the kinetic pattern of inhibition indicated cooperative I binding at 2 sites. Intrinsic K' values ( identical with[I](0.5)(2) extrapolated to [S]=0) for MB, NB and MethB were 0.64+/-0.05, 0.085+/-0.026 and 0.42+/-0.04 microM, respectively. Under the same experimental conditions the dyes acted as single-occupancy, hyperbolic-mixed inhibitors of electric eel acetylcholinesterase (AChE), with K(i)=0.035+/-0.010, 0.026+/-0.0034 and 0.017+/-0.0063 microM (for MB, NB, MethB); alpha (coefficient of competitive interaction)=1.8-2.4 and beta (coefficient of noncompetitive interaction)=0.15-0.28. The complexity of the BChE inhibitory effect of phenoxazine/phenothiazine dyes contrasted with that of conventional ChE inhibitors which cause single-occupancy (n=1), competitive or mixed inhibition in both AChE and BChE and signaled novel modes of ligand interaction at (or remote from) the active site gorge of the latter enzyme.
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Saxena A, Sun W, Luo C, Doctor BP. Human serum butyrylcholinesterase: In vitro and in vivo stability, pharmacokinetics, and safety in mice. Chem Biol Interact 2005; 157-158:199-203. [PMID: 16263104 DOI: 10.1016/j.cbi.2005.10.028] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The use of exogenously administered cholinesterases (ChEs) as bioscavengers of highly toxic organophosphate (OP) nerve agents is now sufficiently well documented to make them a highly viable prophylactic treatment against this potential threat. Of the ChEs evaluated so far, human serum butyrylcholinesterase (HuBChE) is most suitable for human use. A dose of 200 mg (3 mg/kg) of HuBChE is envisioned as a prophylactic treatment in humans that can protect from an exposure of up to 2 x LD50 of soman. In addition to its use as a prophylactic for a variety of wartime scenarios, including covert actions, it also has potential use for first responders (civilians) reacting to terrorist nerve gas release. We recently, developed a procedure for the large-scale purification of HuBChE, which yielded approximately 6 g of highly purified enzyme from 120 kg of Cohn fraction IV-4. The enzyme had a specific activity of 700-750 U/mg and migrated as a single band on SDS-PAGE. To provide data for initiating an investigational new drug (IND) application for the use of this enzyme as a bioscavenger in humans, we established its pharmacokinetic properties, examined its safety in mice, and evaluated its shelf life at various temperatures. In mice administered various doses up to 90 mg/kg, enzyme activity reached peak levels in circulation at 10 and 24 h following i.p. and i.m. injections, respectively. The enzyme displayed a mean residence time (MRT) of 40-50 h, regardless of the route of administration or dose of injected enzyme. Mice were euthanized 2 weeks following enzyme administration and tissues were examined grossly or microscopically for possible toxic effects. Results suggest that HuBChE does not exhibit any toxicity in mice as measured by general observation, serum chemistry, hematology, gross or histologic tissue changes. The shelf life of this enzyme stored at 4, 25, 37, and 45 degrees C was determined in lyophilized form. The enzyme was found to be stable when stored in lyophilized form at -20, 4, 25, or 37 degrees C to date (2 years), as measured by specific activity and SDS polyacrylamide gel electrophoresis. The effect of storage on circulatory stability was determined by measuring MRT in mice; there was no change in the MRT of lyophilized enzyme stored at -20 degrees C to date (2 years). These results provide convincing data that HuBChE is a safe bioscavenger that can provide protection against all OP nerve agents. Efforts are now underway to prepare the required documentation for submission of an IND application to the United States Food and Drug Administration (USFDA).
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Affiliation(s)
- Ashima Saxena
- Division of Biochemistry, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA.
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Doctor BP, Saxena A. Bioscavengers for the protection of humans against organophosphate toxicity. Chem Biol Interact 2005; 157-158:167-71. [PMID: 16293236 DOI: 10.1016/j.cbi.2005.10.024] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Current antidotes for organophosphorus compounds (OP) poisoning consist of a combination of pretreatment with carbamates (pyridostigmine bromide), to protect acetylcholinesterase (AChE) from irreversible inhibition by OP compounds, and post-exposure therapy with anti-cholinergic drugs (atropine sulfate) to counteract the effects of excess acetylcholine and oximes (e.g., 2-PAM chloride) to reactivate OP-inhibited AChE. These antidotes are effective in preventing lethality from OP poisoning, but they do not prevent post-exposure incapacitation, convulsions, seizures, performance decrements, or in many cases permanent brain damage. These symptoms are commonly observed in experimental animals and are likely to occur in humans. The problems intrinsic to these antidotes stimulated attempts to develop a single protective drug, itself devoid of pharmacological effects, which would provide protection against the lethality of OP compounds and prevent post-exposure incapacitation. One approach is the use of enzymes such as cholinesterases (ChEs), beta-esterases in general, as single pretreatment drugs to sequester highly toxic OP anti-ChEs before they reach their physiological targets. This approach turns the irreversible nature of the OP: ChE interaction from disadvantage to an advantage; instead of focusing on OP as an anti-ChE, one can use ChE as an anti-OP. Using this approach, it was shown that administration of fetal bovine serum AChE (FBSAChE) or equine serum butyrylcholinesterase (EqBChE) or human serum BChE (HuBChE) protected the animals from multiple LD50s of a variety of highly toxic OPs without any toxic effects or performance decrements. The bioscavengers that have been explored to date for the detoxification of OPs fall into three categories: (A) those that can catalytically hydrolyze OPs and thus render them non-toxic, such as OP hydrolase and OP anhydrase; (B) those that stoichiometrically bind to OPs, that is, 1 mol of enzyme neutralizes one or 2 mol of OP inactivating both, such as ChEs and related enzymes; and (C) and those generally termed as "pseudo catalytic", e.g., a combination of ChE and an oxime pre-treatment such that the catalytic activity of OP-inhibited ChE can rapidly and continuously be restored in the presence of an oxime. Since the biochemical mechanism underlying prophylaxis by exogenous esterases such as ChEs is established and tested in several animal species, including non-human primates, this concept should allow a reliable extrapolation of results from animal experiments to human application. Having being extensively investigated by several groups, plasma derived HuBChE is judged to be the most suitable bioscavenger for its advancement for human use. The program is being developed at the present time for conducting a safety clinical trial in human volunteers. Several other candidate bioscavengers will follow; e.g., recombinant HuBChE expressed in the milk of transgenic goats, pseudo catalytic scavenger(s), e.g., a combination of ChE and oxime, and possibly PON 1 as a catalytic scavenger in the future.
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Affiliation(s)
- Bhupendra P Doctor
- Division of Biochemistry, Walter Reed Army Institute of Research, 503 Robert Grant Road, Silver Spring, MD 20910, USA.
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Güven M, Sungur M, Eser B, Sari I, Altuntaş F. The effects of fresh frozen plasma on cholinesterase levels and outcomes in patients with organophosphate poisoning. ACTA ACUST UNITED AC 2004; 42:617-23. [PMID: 15462154 DOI: 10.1081/clt-200026967] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE The aim of this study is to determine the effects of fresh frozen plasma, as a source of cholinesterase, on butyrylcholinesterase (BuChE; plasma or pseudo cholinesterase) levels and outcomes in patients with organophosphate poisoning. MATERIALS AND METHODS This prospective study was performed at the Department of Intensive Care of Erciyes University Medical School. Over 2 yrs, patients admitted to the ICU for OP poisoning were entered into the study. OP poisoning was diagnosed on the basis of history and BuChE levels. All patients received atropine. Fresh frozen plasma was given to 12 patients. The study was approved by the Ethical Committee, and verbal informed consent was obtained. RESULTS Thirty-three patients were included in the study. BuChE levels measured at admission and the pralidoxime and atropine doses administered were not different between groups (p>0.05). Although intermediate syndrome developed in 28.6% of patients receiving pralidoxime, there were no intermediate syndrome cases in patients receiving plasma prior to developing intermediate syndrome. The mortality rates were 14.3% in the pralidoxime group and 0% in the plasma+atropine+pralidoxime group. Two patients received plasma after developing the intermediate syndrome, and one patient who received only atropine died. BuChE levels of fresh frozen plasma were 4069.5 +/- 565.1 IU/L. Every two bags of plasma provided an increase in BuChE levels of approximately 461.7 +/- 142.1 IU/L. CONCLUSION Fresh frozen plasma therapy increases BuChE levels in patients with organophosphate poisonings. The administration of plasma may also prevent the development of intermediate syndrome and related mortality. Plasma (fresh frozen or freshly prepared) therapy may be used as an alternative or adjunctive treatment method in patients with organophosphate pesticide poisoning, especially in cases not given pralidoxime. Further randomized controlled and animal studies are required to infer a definitive result.
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Affiliation(s)
- Muhammet Güven
- Department of Intensive Care, Faculty of Medicine, Erciyes University Medical School, 38039, Kayseri, Turkey.
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Fletcher SP, Geyer BC, Smith A, Evron T, Joshi L, Soreq H, Mor TS. Tissue distribution of cholinesterases and anticholinesterases in native and transgenic tomato plants. PLANT MOLECULAR BIOLOGY 2004; 55:33-43. [PMID: 15604663 DOI: 10.1007/s11103-004-0394-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Acetylcholinesterase, a major component of the central and peripheral nervous systems, is ubiquitous among multicellular animals, where its main function is to terminate synaptic transmission by hydrolyzing the neurotransmitter, acetylcholine. However, previous reports describe cholinesterase activities in several plant species and we present data for its presence in tomato plants. Ectopic expression of a recombinant form of the human enzyme and the expression pattern of the transgene and the accumulation of its product in transgenic tomato plants are described. Levels of acetylcholinesterase activity in different tissues are closely effected by and can be separated from alpha-tomatine, an anticholinesterase steroidal glycoalkaloid. The recombinant enzyme can also be separated from the endogenous cholinesterase activity by its subcellular localization and distinct biochemical properties. Our results provide evidence for the co-existence in tomato plants of both acetylcholinesterase activity and a steroidal glycoalkaloid with anticholinesterase activity and suggest spatial mutual exclusivity of these antagonistic activities. Potential functions, including roles in plant-pathogen interactions are discussed.
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Affiliation(s)
- Samuel P Fletcher
- School of Life Sciences and Arizona Biodesign Institute, Arizona State University, USA
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Ashani Y, Segev O, Balan A. The effect of fluoride on the scavenging of organophosphates by human butyrylcholinesterase in buffer solutions and human plasma. Toxicol Appl Pharmacol 2004; 194:90-9. [PMID: 14728983 DOI: 10.1016/j.taap.2003.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Fluoride ion is a reversible inhibitor of human butyrylcholinesterase (HuBChE) that is a viable drug candidate against organophosphates (OPs) toxicity. Since large numbers of communities in many countries are occasionally exposed to relatively high amount of fluoride, its effect on the kinetics of inhibition of HuBChE by OPs was investigated. In saline phosphate, pH 7.4, fluoride in the lower millimolar range significantly slowed the inhibition of HuBChE by paraoxon, DFP, echothiophate, soman, sarin, and VX. The kinetics of the inhibition was found consistent with the formation of a reversible fluoride-HuBChE complex that is at least 25-fold less active towards phosphorylation or phosphonylation than the free enzyme. Heat inactivation experiments indicate that the binding of fluoride to HuBChE probably involves enhanced cross-domain interaction via hydrogen bonds formation that may decrease enzyme activity. In spite of distinct structural differences among the OP used, the dissociation constants of the fluoride-HuBChE reversible complex varied over a narrow range (KF, 0.31-0.70 mM); however, KF in human plasma increased to 2.75-3.40 mM. 19F-NMR spectroscopy revealed that fluoride ion is complexed to plasma components, an observation that explains in part the apparent increase in KF. Results suggest that an estimate of the relative decrease in the rate of OPs sequestration in presence of fluoride can be obtained from the fraction of the free HuBChE (1 + [F]/K(F))(-1). Considering KF values in human plasma, it is concluded that the scavenging efficacy of OPs by HuBChE is not compromised by the normal concentration range of circulating fluoride ions.
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Affiliation(s)
- Yacov Ashani
- Israel Institute for Biological Research, Ness Ziona, Israel.
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Rosenberg Y, Luo C, Ashani Y, Doctor BP, Fischer R, Wolfe G, Saxena A. Pharmacokinetics and immunologic consequences of exposing macaques to purified homologous butyrylcholinesterase. Life Sci 2002; 72:125-34. [PMID: 12417246 DOI: 10.1016/s0024-3205(02)02203-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Exposure to organophosphorus compounds (OPs), in the form of nerve agents and pesticides poses an ever increasing military and civilian threat. In recent years, attention has focused on the use of exogenously administered cholinesterases as an effective prophylactic treatment for protection against OPs. Clearly, a critical prerequisite for any potential bioscavenger is a prolonged circulatory residence time, which is influenced by the size of protein, the microheterogeneity of carbohydrate structures, and the induction (if any) of anti-enzyme antibodies following repeated injections of the enzyme. Previously, it was demonstrated that multiple injections of equine butyrylcholinesterase (BChE) into rabbits, rats, or rhesus monkeys, resulted in a mean residence time spanning several days, and variable immune responses. The present study sought to assess the pharmacokinetics and immunological consequences of administration of purified macaque BChE into macaques of the same species at a dose similar to that required for preventing OP toxicity. An i.v. injection of 7,000 U of homologous enzyme in monkeys demonstrated much longer mean residence times in plasma (MRT = 225 +/- 19 h) compared to those reported for heterologous Hu BChE (33.7 +/- 2.9 h). A smaller second injection of 3,000 U given four weeks later, attained predicted peak plasma levels of enzyme activity, but surprisingly, the MRT in the four macaques showed wide variation and ranged from 54 to 357 h. No antibody response was detected in macaques following either injection of enzyme. These results bode well for the potential use of human BChE as a detoxifying drug in humans.
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