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Jaiswal S, Singh B, Dhingra I, Joshi A, Kodgire P. Bioremediation and bioscavenging for elimination of organophosphorus threats: An approach using enzymatic advancements. ENVIRONMENTAL RESEARCH 2024; 252:118888. [PMID: 38599448 DOI: 10.1016/j.envres.2024.118888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/06/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Organophosphorus compounds (OP) are highly toxic pesticides and nerve agents widely used in agriculture and chemical warfare. The extensive use of these chemicals has severe environmental implications, such as contamination of soil, water bodies, and food chains, thus endangering ecosystems and biodiversity. Plants absorb pesticide residues, which then enter the food chain and accumulate in the body fat of both humans and animals. Numerous human cases of OP poisoning have been linked to both acute and long-term exposure to these toxic OP compounds. These compounds inhibit the action of the acetylcholinesterase enzyme (AChE) by phosphorylation, which prevents the breakdown of acetylcholine (ACh) neurotransmitter into choline and acetate. Thus, it becomes vital to cleanse the environment from these chemicals utilizing various physical, chemical, and biological methods. Biological methods encompassing bioremediation using immobilized microbes and enzymes have emerged as environment-friendly and cost-effective approaches for pesticide removal. Cell/enzyme immobilized systems offer higher stability, reusability, and ease of product recovery, making them ideal tools for OP bioremediation. Interestingly, enzymatic bioscavengers (stoichiometric, pseudo-catalytic, and catalytic) play a vital role in detoxifying pesticides from the human body. Catalytic bioscavenging enzymes such as Organophosphate Hydrolase, Organophosphorus acid anhydrolase, and Paraoxonase 1 show high degradation efficiency within the animal body as well as in the environment. Moreover, these enzymes can also be employed to decontaminate pesticides from food, ensuring food safety and thus minimizing human exposure. This review aims to provide insights to potential collaborators in research organizations, government bodies, and industries to bring advancements in the field of bioremediation and bioscavenging technologies for the mitigation of OP-induced health hazards.
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Affiliation(s)
- Surbhi Jaiswal
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Brijeshwar Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Isha Dhingra
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India
| | - Abhijeet Joshi
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
| | - Prashant Kodgire
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore, Simrol, Khandwa Road, Indore, 453552, India.
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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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Horn G, Rappenglück S, Worek F. Inhibition kinetics of acetylcholinesterase and butyrylcholinesterase from various species by 2-(2-cresyl)-4H-1,3,2-benzodioxaphosphorin-2-oxide (CBDP). Toxicol Lett 2024; 396:28-33. [PMID: 38642675 DOI: 10.1016/j.toxlet.2024.04.003] [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: 12/12/2023] [Revised: 04/02/2024] [Accepted: 04/12/2024] [Indexed: 04/22/2024]
Abstract
The aerotoxic syndrome has been associated with exposure to tricresyl phosphate (TCP), which is used as additive in hydraulic fluids and engine lubricants. The toxic metabolite 2-(2-cresyl)-4H-1,3,2-benzodioxaphosphorin-2-oxide (CBDP) is formed from the TCP isomer tri-ortho-cresyl phosphate (TOCP) in vivo and is known to react with the active site serine in acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) resulting in the inhibition of the enzymes. Previous in vitro studies showed pronounced species differences in the inhibition kinetics of cholinesterases by organophosphorus compounds (OP), which must be considered in the development of relevant animal models for the investigation of OP poisoning and the aerotoxic syndrome. The present study was designed to investigate the inhibition kinetics of human, Cynomolgus monkey, pig, mini pig, guinea pig, mouse, and rat AChE as well as BChE by CBDP under standardized conditions. There were similar rate constants for the inhibition (ki) of human, Cynomolgus monkey and mouse AChE by CBDP. In contrast, the ki values obtained for guinea pig, mini pig, pig, and rat AChE were 2.8- to 5.9-fold lower than that of human AChE. The results of the present study confirmed CBDP as one of the most potent inhibitors of human BChE, indicating a ki value of 3.24 ± 0.33 ×108M-1min-1, which was about 1,140-fold higher than that of human AChE. Accordingly, a markedly more pronounced inhibition rate of BChE from the species guinea pig, mini pig, pig, rat, Cynomolgus monkey, and mouse by CBDP was found as compared to those of AChE from the respective sources, indicating 2.0- to 89.6-fold higher ki values.
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Affiliation(s)
- Gabriele Horn
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany.
| | - Sebastian Rappenglück
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany
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Jiang J, He B, Wei Y, Cui J, Zhang Q, Liu X, Liu D, Wang P, Zhou Z. The toxic effects of combined exposure of chlorpyrifos and p, p'-DDE to zebrafish (Danio rerio) and tissue bioaccumulation. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 248:106194. [PMID: 35623197 DOI: 10.1016/j.aquatox.2022.106194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/23/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Pesticides are widely used and frequently detected in the environment. The evaluation on the toxic effects of the co-exposure of two or more pesticides or related metabolites could reflect the real situation of the exposing risks. In this study, zebrafish was used as a model to investigate the potential toxic interactions of chlorpyrifos and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) on the survival rate, oxidative stress response and neurotoxicity, as well as their bioaccumulation and distribution in tissues. Co-exposure of chlorpyrifos and p,p'-DDE resulted in significant additive acute toxic effects on adult zebrafish with model deviation ratio (MDR) = 1.64. Both 7-day short-term at 1% LC50 and 35-day long-term at 0.5% LC50 co-exposure of chlorpyrifos with p,p'-DDE (50 and 100 µg/L) significantly reduced the survival rate of zebrafish colony to 75 and 82.5%. Co-exposure of chlorpyrifos and p,p'-DDE contributed to increased activity of antioxidant enzyme CAT, SOD and GST and excessive MDA generation, and decreased activity of CarE, CYP450 and AChE, compared with either single exposure of them. In co-exposure, the bioaccumulation of chlorpyrifos and p,p'-DDE was significantly different from the single exposure group. Overall, this study unraveled the potential toxic interaction of chlorpyrifos and p,p'-DDE on zebrafish and provided reference for environmental risk assessment of pesticide mixture.
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Affiliation(s)
- Jiangong Jiang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Bingying He
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Yimu Wei
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Jingna Cui
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Qiang Zhang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Xueke Liu
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Donghui Liu
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
| | - Peng Wang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China.
| | - Zhiqiang Zhou
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China
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Cannon J, Tang S, Yang K, Harrison R, Choi SK. Dual acting oximes designed for therapeutic decontamination of reactive organophosphates via catalytic inactivation and acetylcholinesterase reactivation. RSC Med Chem 2021; 12:1592-1603. [PMID: 34671741 DOI: 10.1039/d1md00194a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/04/2021] [Indexed: 01/24/2023] Open
Abstract
A conventional approach in the therapeutic decontamination of reactive organophosphate (OP) relies on chemical OP degradation by oxime compounds. However, their efficacy is limited due to their lack of activity in the reactivation of acetylcholinesterase (AChE), the primary target of OP. Here, we describe a set of α-nucleophile oxime derivatives which are newly identified for such dual modes of action. Thus, we prepared a 9-member oxime library, each composed of an OP-reactive oxime core linked to an amine-terminated scaffold, which varied through an N-alkyl functionalization. This library was screened by enzyme assays performed with human and electric eel subtypes of OP-inactivated AChE, which led to identifying three oxime leads that displayed significant enhancements in reactivation activity comparable to 2-PAM. They were able to reactivate both enzymes inactivated by three OP types including paraoxon, chlorpyrifos and malaoxon, suggesting their broad spectrum of OP susceptibility. All compounds in the library were able to retain catalytic reactivity in paraoxon inactivation by rates increased up to 5 or 8-fold relative to diacetylmonoxime (DAM) under controlled conditions at pH (8.0, 10.5) and temperature (17, 37 °C). Finally, selected lead compounds displayed superb efficacy in paraoxon decontamination on porcine skin in vitro. In summary, we addressed an unmet need in therapeutic OP decontamination by designing and validating a series of congeneric oximes that display dual modes of action.
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Affiliation(s)
- Jayme Cannon
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School Ann Arbor Michigan 48109 USA .,Department of Internal Medicine, University of Michigan Medical School Ann Arbor Michigan 48109 USA
| | - Shengzhuang Tang
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School Ann Arbor Michigan 48109 USA .,Department of Internal Medicine, University of Michigan Medical School Ann Arbor Michigan 48109 USA
| | - Kelly Yang
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School Ann Arbor Michigan 48109 USA
| | - Racquel Harrison
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School Ann Arbor Michigan 48109 USA
| | - Seok Ki Choi
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School Ann Arbor Michigan 48109 USA .,Department of Internal Medicine, University of Michigan Medical School Ann Arbor Michigan 48109 USA
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Choi SK. Nanomaterial-Enabled Sensors and Therapeutic Platforms for Reactive Organophosphates. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:224. [PMID: 33467113 PMCID: PMC7830340 DOI: 10.3390/nano11010224] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 12/29/2020] [Accepted: 01/14/2021] [Indexed: 01/15/2023]
Abstract
Unintended exposure to harmful reactive organophosphates (OP), which comprise a group of nerve agents and agricultural pesticides, continues to pose a serious threat to human health and ecosystems due to their toxicity and prolonged stability. This underscores an unmet need for developing technologies that will allow sensitive OP detection, rapid decontamination and effective treatment of OP intoxication. Here, this article aims to review the status and prospect of emerging nanotechnologies and multifunctional nanomaterials that have shown considerable potential in advancing detection methods and treatment modalities. It begins with a brief introduction to OP types and their biochemical basis of toxicity followed by nanomaterial applications in two topical areas of primary interest. One topic relates to nanomaterial-based sensors which are applicable for OP detection and quantitative analysis by electrochemical, fluorescent, luminescent and spectrophotometric methods. The other topic is directed on nanotherapeutic platforms developed as OP remedies, which comprise nanocarriers for antidote drug delivery and nanoscavengers for OP inactivation and decontamination. In summary, this article addresses OP-responsive nanomaterials, their design concepts and growing impact on advancing our capability in the development of OP sensors, decontaminants and therapies.
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Affiliation(s)
- Seok Ki Choi
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan Medical School, Ann Arbor, MI 48109, USA;
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Hrvat NM, Kovarik Z. Counteracting poisoning with chemical warfare nerve agents. Arh Hig Rada Toksikol 2020; 71:266-284. [PMID: 33410774 PMCID: PMC7968514 DOI: 10.2478/aiht-2020-71-3459] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/01/2020] [Accepted: 11/01/2020] [Indexed: 12/14/2022] Open
Abstract
Phosphylation of the pivotal enzyme acetylcholinesterase (AChE) by nerve agents (NAs) leads to irreversible inhibition of the enzyme and accumulation of neurotransmitter acetylcholine, which induces cholinergic crisis, that is, overstimulation of muscarinic and nicotinic membrane receptors in the central and peripheral nervous system. In severe cases, subsequent desensitisation of the receptors results in hypoxia, vasodepression, and respiratory arrest, followed by death. Prompt action is therefore critical to improve the chances of victim's survival and recovery. Standard therapy of NA poisoning generally involves administration of anticholinergic atropine and an oxime reactivator of phosphylated AChE. Anticholinesterase compounds or NA bioscavengers can also be applied to preserve native AChE from inhibition. With this review of 70 years of research we aim to present current and potential approaches to counteracting NA poisoning.
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Affiliation(s)
| | - Zrinka Kovarik
- Institute for Medical Research and Occupational Health, Zagreb, Croatia
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Enantioseparation, in vitro testing, and structural characterization of triple-binding reactivators of organophosphate-inhibited cholinesterases. Biochem J 2020; 477:2771-2790. [PMID: 32639532 DOI: 10.1042/bcj20200192] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 11/17/2022]
Abstract
The enantiomers of racemic 2-hydroxyimino-N-(azidophenylpropyl)acetamide-derived triple-binding oxime reactivators were separated, and tested for inhibition and reactivation of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibited with tabun (GA), cyclosarin (GF), sarin (GB), and VX. Both enzymes showed the greatest affinity toward the methylimidazole derivative (III) of 2-hydroxyimino-N-(azidophenylpropyl)acetamide (I). The crystal structure was determined for the complex of oxime III within human BChE, confirming that all three binding groups interacted with active site residues. In the case of BChE inhibited by GF, oximes I (kr = 207 M-1 min-1) and III (kr = 213 M-1 min-1) showed better reactivation efficiency than the reference oxime 2-PAM. Finally, the key mechanistic steps in the reactivation of GF-inhibited BChE with oxime III were modeled using the PM7R6 method, stressing the importance of proton transfer from Nε of His438 to Oγ of Ser203 for achieving successful reactivation.
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Wong PT, Tang S, Cannon J, Yang K, Harrison R, Ruge M, O'Konek JJ, Choi SK. Shielded α-Nucleophile Nanoreactor for Topical Decontamination of Reactive Organophosphate. ACS APPLIED MATERIALS & INTERFACES 2020; 12:33500-33515. [PMID: 32603588 DOI: 10.1021/acsami.0c08946] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Here, we describe a nanoscale reactor strategy with a topical application in the therapeutic decontamination of reactive organophosphates (OPs) as chemical threat agents. It involves functionalization of poly(amidoamine) dendrimer through a combination of its partial PEG shielding and exhaustive conjugation with an OP-reactive α-nucleophile moiety at its peripheral branches. We prepared a 16-member library composed of two α-nucleophile classes (oxime, hydroxamic acid), each varying in its reactor valency (43-176 reactive units per nanoparticle), and linker framework for α-nucleophile tethering. Their mechanism for OP inactivation occurred via nucleophilic catalysis as verified against P-O and P-S bonded OPs including paraoxon-ethyl (POX), malaoxon, and omethoate by 1H NMR spectroscopy. Screening their reactivity for POX inactivation was performed under pH- and temperature-controlled conditions, which resulted in identifying 13 conjugates, each showing shorter POX half-life up to 2 times as compared to a reference Dekon 139 at pH 10.5, 37 °C. Of these, 10 conjugates were further confirmed for greater efficacy in POX decontamination experiments performed in two skin models, porcine skin and an artificial human microtissue. Finally, a few lead conjugates were selected and demonstrated for their biocompatibility in vitro as evident with lack of skin absorption, no inhibition of acetylcholinesterase (AChE), and no cytotoxicity in human neuroblastoma cells. In summary, this study presents a novel nanoreactor library, its screening methods, and identification of potent lead conjugates with potential for therapeutic OP decontamination.
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Butyrylcholinesterase, a stereospecific in vivo bioscavenger against nerve agent intoxication. Biochem Pharmacol 2020; 171:113670. [DOI: 10.1016/j.bcp.2019.113670] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/14/2019] [Indexed: 11/18/2022]
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Wong PT, Bhattacharjee S, Cannon J, Tang S, Yang K, Bowden S, Varnau V, O'Konek JJ, Choi SK. Reactivity and mechanism of α-nucleophile scaffolds as catalytic organophosphate scavengers. Org Biomol Chem 2019; 17:3951-3963. [PMID: 30942252 DOI: 10.1039/c9ob00503j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Despite their unique benefits imparted by their structure and reactivity, certain α-nucleophile molecules remain underexplored as chemical inactivators for the topical decontamination of reactive organophosphates (OPs). Here, we present a library of thirty α-nucleophile scaffolds, each designed with either a pyridinium aldoxime (PAM) or hydroxamic acid (HA) α-nucleophile core tethered to a polar or charged scaffold for optimized physicochemical properties and reactivity. These library compounds were screened for their abilities to catalyze the hydrolysis of a model OP, paraoxon (POX), in kinetic assays. These screening experiments led to the identification of multiple lead compounds with the ability to inactivate POX two- to four-times more rapidly than Dekon 139-the active ingredient currently used for skin decontamination of OPs. Our mechanistic studies, performed under variable pH and temperature conditions suggested that the differences in the reactivity and activation energy of these compounds are fundamentally attributable to the core nucleophilicity and pKa. Following their screening and mechanistic studies, select lead compounds were further evaluated and demonstrated greater efficacy than Dekon 139 in the topical decontamination of POX in an ex vivo porcine skin model. In addition to OP reactivity, several compounds in the PAM class displayed a dual mode of activity, as they retained the ability to reactivate POX-inhibited acetylcholine esterase (AChE). In summary, this report describes a rationale for the hydrophilic scaffold design of α-nucleophiles, and it offers advanced insights into their chemical reactivity, mechanism, and practical utility as OP decontaminants.
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Affiliation(s)
- Pamela T Wong
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
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Myers TM. Human plasma-derived butyrylcholinesterase is behaviorally safe and effective in cynomolgus macaques (Macaca fascicularis) challenged with soman. Chem Biol Interact 2019; 308:170-178. [DOI: 10.1016/j.cbi.2019.05.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/24/2019] [Accepted: 05/13/2019] [Indexed: 11/26/2022]
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13
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Catalytic bioscavengers as countermeasures against organophosphate nerve agents. Chem Biol Interact 2018; 292:50-64. [DOI: 10.1016/j.cbi.2018.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 12/30/2022]
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Dafferner AJ, Schopfer LM, Xiao G, Cashman JR, Yerramalla U, Johnson RC, Blake TA, Lockridge O. Immunopurification of Acetylcholinesterase from Red Blood Cells for Detection of Nerve Agent Exposure. Chem Res Toxicol 2017; 30:1897-1910. [PMID: 28892361 PMCID: PMC5646370 DOI: 10.1021/acs.chemrestox.7b00209] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Nerve agents and
organophosphorus pesticides make a covalent bond
with the active site serine of acetylcholinesterase (AChE), resulting
in inhibition of AChE activity and toxic symptoms. AChE in red blood
cells (RBCs) serves as a surrogate for AChE in the nervous system.
Mass spectrometry analysis of adducts on RBC AChE could provide evidence
of exposure. Our goal was to develop a method of immunopurifying human
RBC AChE in quantities adequate for detecting exposure by mass spectrometry.
For this purpose, we immobilized 3 commercially available anti-human
acetylcholinesterase monoclonal antibodies (AE-1, AE-2, and HR2) plus
3 new monoclonal antibodies. The monoclonal antibodies were characterized
for binding affinity, epitope mapping by pairing analysis, and nucleotide
and amino acid sequences. AChE was solubilized from frozen RBCs with
1% (v/v) Triton X-100. A 16 mL sample containing 5.8 μg of RBC
AChE was treated with a quantity of soman model compound that inhibited
50% of the AChE activity. Native and soman-inhibited RBC AChE samples
were immunopurified on antibody–Sepharose beads. The immunopurified
RBC AChE was digested with pepsin and analyzed by liquid chromatography
tandem mass spectrometry on a 6600 Triple-TOF mass spectrometer. The
aged soman-modified PheGlyGluSerAlaGlyAlaAlaSer (FGESAGAAS) peptide
was detected using a targeted analysis method. It was concluded that
all 6 monoclonal antibodies could be used to immunopurify RBC AChE
and that exposure to nerve agents could be detected as adducts on
the active site serine of RBC AChE.
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Affiliation(s)
- Alicia J Dafferner
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
| | - Lawrence M Schopfer
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
| | - Gaoping Xiao
- Syd Labs, Inc , Natick, Massachusetts 01760, United States
| | - John R Cashman
- Human BioMolecular Research Institute , 5310 Eastgate Mall, San Diego, California 92121, United States
| | - Udaya Yerramalla
- Precision Antibody , 91330 Red Branch Rd, Columbia, Maryland 21045, United States
| | - Rudolph C Johnson
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , 4770 Buford Highway, Chamblee, Georgia 30341, United States
| | - Thomas A Blake
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , 4770 Buford Highway, Chamblee, Georgia 30341, United States
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
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Stereospecific cholinesterase inhibition by O , S -diethylphenylphosphonothioate. Bioorg Med Chem 2017; 25:3053-3058. [DOI: 10.1016/j.bmc.2017.03.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 03/25/2017] [Indexed: 11/20/2022]
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16
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Masson P, Nachon F. Cholinesterase reactivators and bioscavengers for pre- and post-exposure treatments of organophosphorus poisoning. J Neurochem 2017; 142 Suppl 2:26-40. [PMID: 28542985 DOI: 10.1111/jnc.14026] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/02/2017] [Accepted: 03/10/2017] [Indexed: 12/11/2022]
Abstract
Organophosphorus agents (OPs) irreversibly inhibit acetylcholinesterase (AChE) causing a major cholinergic syndrome. The medical counter-measures of OP poisoning have not evolved for the last 30 years with carbamates for pretreatment, pyridinium oximes-based AChE reactivators, antimuscarinic drugs and neuroprotective benzodiazepines for post-exposure treatment. These drugs ensure protection of peripheral nervous system and mitigate acute effects of OP lethal doses. However, they have significant limitations. Pyridostigmine and oximes do not protect/reactivate central AChE. Oximes poorly reactivate AChE inhibited by phosphoramidates. In addition, current neuroprotectants do not protect the central nervous system shortly after the onset of seizures when brain damage becomes irreversible. New therapeutic approaches for pre- and post-exposure treatments involve detoxification of OP molecules before they reach their molecular targets by administrating catalytic bioscavengers, among them phosphotriesterases are the most promising. Novel generation of broad spectrum reactivators are designed for crossing the blood-brain barrier and reactivate central AChE. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Patrick Masson
- Neuropharmacology Laboratory, Kazan Federal University, Kazan, Russia
| | - Florian Nachon
- Institut de Recherche Biomédicale des Armées, Brétigny-sur-Orge, Cédex, France
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17
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Duarte DJ, Rutten JM, van den Berg M, Westerink RH. In vitro neurotoxic hazard characterization of different tricresyl phosphate (TCP) isomers and mixtures. Neurotoxicology 2017; 59:222-230. [DOI: 10.1016/j.neuro.2016.02.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 12/01/2022]
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18
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Masson P. Novel approaches in prophylaxis/pretreatment and treatment of organophosphorus poisoning. PHOSPHORUS SULFUR 2016. [DOI: 10.1080/10426507.2016.1211652] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Patrick Masson
- Neuropharmacology Laboratory, Kazan Federal University, Kazan, Russian Federation
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19
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Sokolov OI, Selivanov NY, Bogatyrev VA, Selivanova OG, Velikorodnaya YI, Pocheptsov AY, Filatov BN, Shchyogolev SY, Dykman LA. Synthesis and study on activity in vitro of the high purity human butyrylcholinesterase conjugated with gold nanoparticles. DOKL BIOCHEM BIOPHYS 2016; 468:232-4. [PMID: 27417730 DOI: 10.1134/s1607672916030212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Indexed: 01/16/2023]
Abstract
The aim of this research was to design a method of immobilization of high-purity human butyrylcholinesterase on the surface of gold nanoparticles preserving the activity of the enzyme. In order to achieve this aim, the method of fractionation and purification of human butyrylcholinesterase from plasma was modified. The synthesis of 15-nm gold nanoparticles was carried out by citrated method. A method of conjugation of the high-purity butyrylcholinesterase with gold nanoparticles was developed. It was found that the Immobilization of butyrylcholinesterase on the surface of gold nanoparticles resulted in a significant (to 23%) increase in the specific activity of the enzyme.
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Affiliation(s)
- O I Sokolov
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410015, Russia.
| | - N Y Selivanov
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410015, Russia
| | - V A Bogatyrev
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410015, Russia
| | - O G Selivanova
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410015, Russia
| | - Y I Velikorodnaya
- Research Institute of Hygiene, Toxicology, and Occupational Pathology Federal Biomedical Agency, ul. Zemlyachki 12, Volgograd, 400048, Russia
| | - A Y Pocheptsov
- Research Institute of Hygiene, Toxicology, and Occupational Pathology Federal Biomedical Agency, ul. Zemlyachki 12, Volgograd, 400048, Russia
| | - B N Filatov
- Research Institute of Hygiene, Toxicology, and Occupational Pathology Federal Biomedical Agency, ul. Zemlyachki 12, Volgograd, 400048, Russia
| | - S Y Shchyogolev
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410015, Russia
| | - L A Dykman
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, pr. Entuziastov 13, Saratov, 410015, Russia
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20
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Zhang P, Jain P, Tsao C, Sinclair A, Sun F, Hung HC, Bai T, Wu K, Jiang S. Butyrylcholinesterase nanocapsule as a long circulating bioscavenger with reduced immune response. J Control Release 2016; 230:73-8. [DOI: 10.1016/j.jconrel.2016.04.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 04/05/2016] [Indexed: 10/22/2022]
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21
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Rosenberg YJ, Walker J, Jiang X, Donahue S, Robosky J, Sack M, Lees J, Urban L. A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions. Sci Rep 2015; 5:13247. [PMID: 26268538 PMCID: PMC4642508 DOI: 10.1038/srep13247] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 07/22/2015] [Indexed: 11/09/2022] Open
Abstract
Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1-2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product.
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Affiliation(s)
| | | | | | | | | | - Markus Sack
- Institute for molecular Biotechnology, RWTH Aachen University, Aachen, Germany
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22
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Noy-Porat T, Cohen O, Ehrlich S, Epstein E, Alcalay R, Mazor O. Acetylcholinesterase-Fc Fusion Protein (AChE-Fc): A Novel Potential Organophosphate Bioscavenger with Extended Plasma Half-Life. Bioconjug Chem 2015; 26:1753-8. [DOI: 10.1021/acs.bioconjchem.5b00305] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Tal Noy-Porat
- Departments
of Biochemistry and Molecular Genetics and ‡Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ofer Cohen
- Departments
of Biochemistry and Molecular Genetics and ‡Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Sharon Ehrlich
- Departments
of Biochemistry and Molecular Genetics and ‡Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Eyal Epstein
- Departments
of Biochemistry and Molecular Genetics and ‡Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ron Alcalay
- Departments
of Biochemistry and Molecular Genetics and ‡Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ohad Mazor
- Departments
of Biochemistry and Molecular Genetics and ‡Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
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23
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Pang Z, Hu CMJ, Fang RH, Luk BT, Gao W, Wang F, Chuluun E, Angsantikul P, Thamphiwatana S, Lu W, Jiang X, Zhang L. Detoxification of Organophosphate Poisoning Using Nanoparticle Bioscavengers. ACS NANO 2015; 9:6450-8. [PMID: 26053868 PMCID: PMC4832962 DOI: 10.1021/acsnano.5b02132] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Organophosphate poisoning is highly lethal as organophosphates, which are commonly found in insecticides and nerve agents, cause irreversible phosphorylation and inactivation of acetylcholinesterase (AChE), leading to neuromuscular disorders via accumulation of acetylcholine in the body. Direct interception of organophosphates in the systemic circulation thus provides a desirable strategy in treatment of the condition. Inspired by the presence of AChE on red blood cell (RBC) membranes, we explored a biomimetic nanoparticle consisting of a polymeric core surrounded by RBC membranes to serve as an anti-organophosphate agent. Through in vitro studies, we demonstrated that the biomimetic nanoparticles retain the enzymatic activity of membrane-bound AChE and are able to bind to a model organophosphate, dichlorvos, precluding its inhibitory effect on other enzymatic substrates. In a mouse model of organophosphate poisoning, the nanoparticles were shown to improve the AChE activity in the blood and markedly improved the survival of dichlorvos-challenged mice.
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Affiliation(s)
- Zhiqing Pang
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
- Department of Pharmaceutics, School of Pharmacy, Fudan University, and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, P. R. China
| | - Che-Ming J. Hu
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Ronnie H. Fang
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Brian T. Luk
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Weiwei Gao
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Fei Wang
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
- Department of Pharmaceutics, School of Pharmacy, Fudan University, and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, P. R. China
| | - Erdembileg Chuluun
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Pavimol Angsantikul
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Soracha Thamphiwatana
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
| | - Weiyue Lu
- Department of Pharmaceutics, School of Pharmacy, Fudan University, and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, P. R. China
| | - Xinguo Jiang
- Department of Pharmaceutics, School of Pharmacy, Fudan University, and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education, Shanghai 201203, P. R. China
| | - Liangfang Zhang
- Department of NanoEngineering and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, U.S.A
- Corresponding author, Tel: 858-246-0999,
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24
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Atsmon J, Brill-Almon E, Nadri-Shay C, Chertkoff R, Alon S, Shaikevich D, Volokhov I, Haim KY, Bartfeld D, Shulman A, Ruderfer I, Ben-Moshe T, Shilovitzky O, Soreq H, Shaaltiel Y. Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R. Toxicol Appl Pharmacol 2015; 287:202-9. [PMID: 26051873 DOI: 10.1016/j.taap.2015.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 05/27/2015] [Accepted: 06/01/2015] [Indexed: 12/18/2022]
Abstract
PRX-105 is a plant-derived recombinant version of the human 'read-through' acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50nmol/kg PRX-105, 2min before being exposed to 1.33×LD50 and 1.5×LD50 of toxin and 10min after exposure to 1.5×LD50 survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t½) in mice was 994 (±173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t½ in humans was substantially longer than in mice (average 26.7h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation.
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Affiliation(s)
- Jacob Atsmon
- Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel
| | | | | | | | - Sari Alon
- Protalix Biotherapeutics, Science Park, Carmiel, Israel
| | - Dimitri Shaikevich
- Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - Inna Volokhov
- Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - Kirsten Y Haim
- Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel
| | | | - Avidor Shulman
- Protalix Biotherapeutics, Science Park, Carmiel, Israel.
| | - Ilya Ruderfer
- Protalix Biotherapeutics, Science Park, Carmiel, Israel
| | | | | | - Hermona Soreq
- Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
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25
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Podestà A, Rossi S, Massarelli I, Carpi S, Adinolfi B, Fogli S, Bianucci AM, Nieri P. Selection of a human butyrylcholinesterase-like antibody single-chain variable fragment resistant to AChE inhibitors from a phage library expressed in E. coli. MAbs 2014; 6:1084-93. [PMID: 24675419 DOI: 10.4161/mabs.28635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Organophosphates are potent poisoning agents that cause severe cholinergic toxicity. Current treatment has been reported to be unsatisfactory and novel antidotes are needed. In this study, we used a single-chain variable fragment (scFv) library to select a recombinant antibody fragment (WZ1-14.2.1) with butyrylcholinesterase-like catalytic activity by using an innovative method integrating genetic selection and the bait-and-switch strategy. Ellman assay demonstrated that WZ1-14.2.1 has Michaelis-Menten kinetics in the hydrolysis of all the three substrates used, acetylthiocholine, propionylthiocholine and butyrylthiocholine. Notably, the catalytic activity was resistant to the following acetylcholinesterase inhibitors: neostigmine, iso-OMPA, chlorpyrifos oxon, dichlorvos, and paraoxon ethyl. Otherwise, the enzymatic activity of WZ1-14.2.1 was inhibited by the selective butyrylcholinesterase inhibitor, ethopropazine, and by the Ser-blocking agent phenylmethanesuphonyl fluoride. A hypothetical 3D structure of the WZ1-14.2.1 catalytic site, compatible with functional results, is proposed on the basis of a molecular modeling analysis.
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26
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Fang L, Zheng F, Zhan CG. A model of glycosylated human butyrylcholinesterase. MOLECULAR BIOSYSTEMS 2014; 10:348-54. [PMID: 24327294 PMCID: PMC3947857 DOI: 10.1039/c3mb70313d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human butyrylcholinesterase (BChE) and its mutants have shown great potential in treating cocaine overdose and addiction. In order to effectively suppress cocaine reward in the brain for a long period of time after an exogenous cocaine hydrolase administration, the therapeutic enzyme should have not only a high catalytic efficiency against cocaine, but also a sufficiently long circulation time. It has been known that PEGylation (covalent attachment of polyethylene glycol) modification of a therapeutic protein can prolong the biological half-life of the protein without affecting its biological function. However, the asparagine-linked glycans on the surface of glycosylated BChE may interfere with the PEGylation modification. In this study, we built a three-dimensional (3D) model of glycosylated human BChE to investigate the influence of glycans on the PEGylation modification. Glycans did not change the overall stability of the BChE structure, but could increase the flexibility of some local structures. For further evaluating the accessibility of the PEGylation reaction sites, particularly lysine residues, on the protein surface, we calculated the Solvent Accessible Surface Areas (SASAs) of these residues. The results indicate that some lysine residues show a significant decrease in SASA due to the direct or indirect influence of their surrounding glycans. The results also indicate that PEGylation reaction agents with smaller functional groups could have a better chance to react with lysine residues. This investigation provides a structural basis for rational engineering of human BChE and its mutants as therapeutic candidates.
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Affiliation(s)
- Lei Fang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536, USA.
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27
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Bharathi S, Wong PT, Desai A, Lykhytska O, Choe V, Kim H, Thomas TP, Baker JR, Choi SK. Design and mechanistic investigation of oxime-conjugated PAMAM dendrimers as the catalytic scavenger of reactive organophosphate. J Mater Chem B 2014; 2:1068-1078. [DOI: 10.1039/c3tb21267j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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28
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Nachon F, Brazzolotto X, Trovaslet M, Masson P. Progress in the development of enzyme-based nerve agent bioscavengers. Chem Biol Interact 2013; 206:536-44. [PMID: 23811386 DOI: 10.1016/j.cbi.2013.06.012] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/15/2013] [Accepted: 06/18/2013] [Indexed: 11/17/2022]
Abstract
Acetylcholinesterase is the physiological target for acute toxicity of nerve agents. Attempts to protect acetylcholinesterase from phosphylation by nerve agents, is currently achieved by reversible inhibitors that transiently mask the enzyme active site. This approach either protects only peripheral acetylcholinesterase or may cause side effects. Thus, an alternative strategy consists in scavenging nerve agents in the bloodstream before they can reach acetylcholinesterase. Pre- or post-exposure administration of bioscavengers, enzymes that neutralize and detoxify organophosphorus molecules, is one of the major developments of new medical counter-measures. These enzymes act either as stoichiometric or catalytic bioscavengers. Human butyrylcholinesterase is the leading stoichiometric bioscavenger. Current efforts are devoted to its mass production with care to pharmacokinetic properties of the final product for extended lifetime. Development of specific reactivators of phosphylated butyrylcholinesterase, or variants with spontaneous reactivation activity is also envisioned for rapid in situ regeneration of the scavenger. Human paraoxonase 1 is the leading catalytic bioscavenger under development. Research efforts focus on improving its catalytic efficiency toward the most toxic isomers of nerve agents, by means of directed evolution-based strategies. Human prolidase appears to be another promising human enzyme. Other non-human efficient enzymes like bacterial phosphotriesterases or squid diisopropylfluorophosphatase are also considered though their intrinsic immunogenic properties remain challenging for use in humans. Encapsulation, PEGylation and other modifications are possible solutions to address this problem as well as that of their limited lifetime. Finally, gene therapy for in situ generation and delivery of bioscavengers is for the far future, but its proof of concept has been established.
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Affiliation(s)
- Florian Nachon
- Institut de Recherche Biomédicale des Armées, BP87, 38702 La Tronche Cédex, France.
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29
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Myers TM, Sun W, Naik RS, Clark MG, Doctor BP, Saxena A. Characterization of human serum butyrylcholinesterase in rhesus monkeys: Behavioral and physiological effects. Neurotoxicol Teratol 2012; 34:323-30. [DOI: 10.1016/j.ntt.2012.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/16/2012] [Accepted: 02/21/2012] [Indexed: 11/25/2022]
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30
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Duysen EG, Koentgen F, Williams GR, Timperley CM, Schopfer LM, Cerasoli DM, Lockridge O. Production of ES1 plasma carboxylesterase knockout mice for toxicity studies. Chem Res Toxicol 2011; 24:1891-8. [PMID: 21875074 DOI: 10.1021/tx200237a] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The LD(50) for soman is 10-20-fold higher for a mouse than a human. The difference in susceptibility is attributed to the presence of carboxylesterase in mouse but not in human plasma. Our goal was to make a mouse lacking plasma carboxylesterase. We used homologous recombination to inactivate the carboxylesterase ES1 gene on mouse chromosome 8 by deleting exon 5 and by introducing a frame shift for amino acids translated from exons 6 to 13. ES1-/- mice have no detectable carboxylesterase activity in plasma but have normal carboxylesterase activity in tissues. Homozygous ES1-/- mice and wild-type littermates were tested for response to a nerve agent model compound (soman coumarin) at 3 mg/kg sc. This dose intoxicated both genotypes but was lethal only to ES1-/- mice. This demonstrated that plasma carboxylesterase protects against a relatively high toxicity organophosphorus compound. The ES1-/- mouse should be an appropriate model for testing highly toxic nerve agents and for evaluating protection strategies against the toxicity of nerve agents.
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Affiliation(s)
- Ellen G Duysen
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
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31
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Carletti E, Schopfer LM, Colletier JP, Froment MT, Nachon F, Weik M, Lockridge O, Masson P. Reaction of cresyl saligenin phosphate, the organophosphorus agent implicated in aerotoxic syndrome, with human cholinesterases: mechanistic studies employing kinetics, mass spectrometry, and X-ray structure analysis. Chem Res Toxicol 2011; 24:797-808. [PMID: 21438623 PMCID: PMC3118852 DOI: 10.1021/tx100447k] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aerotoxic syndrome is assumed to be caused by exposure to tricresyl phosphate (TCP), an antiwear additive in jet engine lubricants and hydraulic fluid. CBDP (2-(ortho-cresyl)-4H-1,2,3-benzodioxaphosphoran-2-one) is the toxic metabolite of triortho-cresylphosphate, a component of TCP. Human butyrylcholinesterase (BChE; EC 3.1.1.8) and human acetylcholinesterase (AChE; EC 3.1.1.7) are irreversibly inhibited by CBDP. The bimolecular rate constants of inhibition (k(i)), determined under pseudo-first-order conditions, displayed a biphasic time course of inhibition with k(i) of 1.6 × 10(8) M(-1) min(-1) and 2.7 × 10(7) M(-1) min(-1) for E and E' forms of BChE. The inhibition constants for AChE were 1 to 2 orders of magnitude slower than those for BChE. CBDP-phosphorylated cholinesterases are nonreactivatable due to ultra fast aging. Mass spectrometry analysis showed an initial BChE adduct with an added mass of 170 Da from cresylphosphate, followed by dealkylation to a structure with an added mass of 80 Da. Mass spectrometry in (18)O-water showed that (18)O was incorporated only during the final aging step to form phospho-serine as the final aged BChE adduct. The crystal structure of CBDP-inhibited BChE confirmed that the phosphate adduct is the ultimate aging product. CBDP is the first organophosphorus agent that leads to a fully dealkylated phospho-serine BChE adduct.
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Affiliation(s)
- Eugénie Carletti
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble, France
| | - Lawrence M. Schopfer
- Eppley Institute and Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
| | - Jacques-Philippe Colletier
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble, France
| | - Marie-Thérése Froment
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées (IRBA)-Centre de Recherches du Service de Santé des Armées (CRSSA), 24 av des Marquis du Grésivaudan, 38702 La Tronche, France
| | - Florian Nachon
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées (IRBA)-Centre de Recherches du Service de Santé des Armées (CRSSA), 24 av des Marquis du Grésivaudan, 38702 La Tronche, France
| | - Martin Weik
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble, France
| | - Oksana Lockridge
- Eppley Institute and Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
| | - Patrick Masson
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble, France
- Eppley Institute and Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées (IRBA)-Centre de Recherches du Service de Santé des Armées (CRSSA), 24 av des Marquis du Grésivaudan, 38702 La Tronche, France
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Wandhammer M, Carletti E, Van der Schans M, Gillon E, Nicolet Y, Masson P, Goeldner M, Noort D, Nachon F. Structural study of the complex stereoselectivity of human butyrylcholinesterase for the neurotoxic V-agents. J Biol Chem 2011; 286:16783-9. [PMID: 21454498 PMCID: PMC3089521 DOI: 10.1074/jbc.m110.209569] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 02/28/2011] [Indexed: 11/06/2022] Open
Abstract
Nerve agents are chiral organophosphate compounds (OPs) that exert their acute toxicity by phosphorylating the catalytic serine of acetylcholinesterase (AChE). The inhibited cholinesterases can be reactivated using oximes, but a spontaneous time-dependent process called aging alters the adduct, leading to resistance toward oxime reactivation. Human butyrylcholinesterase (BChE) functions as a bioscavenger, protecting the cholinergic system against OPs. The stereoselectivity of BChE is an important parameter for its efficiency at scavenging the most toxic OPs enantiomer for AChE. Crystals of BChE inhibited in solution or in cristallo with racemic V-agents (VX, Russian VX, and Chinese VX) systematically show the formation of the P(S) adduct. In this configuration, no catalysis of aging seems possible as confirmed by the three-dimensional structures of the three conjugates incubated over a period exceeding a week. Crystals of BChE soaked in optically pure VX(R)-(+) and VX(S)-(-) solutions lead to the formation of the P(S) and P(R) adduct, respectively. These structural data support an in-line phosphonylation mechanism. Additionally, they show that BChE reacts with VX(R)-(+) in the presence of racemic mixture of V-agents, at odds with earlier kinetic results showing a moderate higher inhibition rate for VX(S)-(-). These combined results suggest that the simultaneous presence of both enantiomers alters the enzyme stereoselectivity. In summary, the three-dimensional data show that BChE reacts preferentially with P(R) enantiomer of V-agents and does not age, in complete contrast to AChE, which is selectively inhibited by the P(S) enantiomer and ages.
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Affiliation(s)
- Marielle Wandhammer
- From the Département de Toxicologie, Institut de Recherche Biomédicale des Armées-CRSSA, 38700 La Tronche, France
- the Laboratoire de Conception et Application de Molécules Bioactives, UMR 7199, Faculté de Pharmacie, 67400 Illkirch, France
| | - Eugénie Carletti
- From the Département de Toxicologie, Institut de Recherche Biomédicale des Armées-CRSSA, 38700 La Tronche, France
| | - Marcel Van der Schans
- the Research Group Diagnosis and Therapy, Business Unit Biological and Chemical Protection, TNO Defence, Security and Safety, 2288 GJ Rijswijk, The Netherlands, and
| | - Emilie Gillon
- From the Département de Toxicologie, Institut de Recherche Biomédicale des Armées-CRSSA, 38700 La Tronche, France
| | - Yvain Nicolet
- the Laboratoire de Cristallographie et Cristallogenèse des Protéines, Institut de Biologie Structurale, 38027 Grenoble, France
| | - Patrick Masson
- From the Département de Toxicologie, Institut de Recherche Biomédicale des Armées-CRSSA, 38700 La Tronche, France
| | - Maurice Goeldner
- the Laboratoire de Conception et Application de Molécules Bioactives, UMR 7199, Faculté de Pharmacie, 67400 Illkirch, France
| | - Daan Noort
- the Research Group Diagnosis and Therapy, Business Unit Biological and Chemical Protection, TNO Defence, Security and Safety, 2288 GJ Rijswijk, The Netherlands, and
| | - Florian Nachon
- From the Département de Toxicologie, Institut de Recherche Biomédicale des Armées-CRSSA, 38700 La Tronche, France
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Masson P. Evolution of and perspectives on therapeutic approaches to nerve agent poisoning. Toxicol Lett 2011; 206:5-13. [PMID: 21524695 DOI: 10.1016/j.toxlet.2011.04.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 04/08/2011] [Indexed: 01/18/2023]
Abstract
After more than 70 years of considerable efforts, research on medical defense against nerve agents has come to a standstill. Major progress in medical countermeasures was achieved between the 50s and 70s with the development of anticholinergic drugs and carbamate-based pretreatment, the introduction of pyridinium oximes as antidotes, and benzodiazepines in emergency treatments. These drugs ensure good protection of the peripheral nervous system and mitigate the acute effects of exposure to lethal doses of nerve agents. However, pyridostigmine and cholinesterase reactivators currently used in the armed forces do not protect/reactivate central acetylcholinesterases. Moreover, other drugs used are not sufficiently effective in protecting the central nervous system against seizures, irreversible brain damages and long-term sequelae of nerve agent poisoning.New developments of medical counter-measures focus on: (a) detoxification of organophosphorus molecules before they react with acetylcholinesterase and other physiological targets by administration of stoichiometric or catalytic scavengers; (b) protection and reactivation of central acetylcholinesterases, and (c) improvement of neuroprotection following delayed therapy.Future developments will aim at treatment of acute and long-term effects of low level exposure to nerve agents, research on alternative routes for optimizing drug delivery, and therapies. Though gene therapy for in situ generation of bioscavengers, and cell therapy based on neural progenitor engraftment for neuronal regeneration have been successfully explored, more studies are needed before practical medical applications can be made of these new approaches.
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Affiliation(s)
- Patrick Masson
- IRBA-CRSSA, Toxicology Dept., 38702 La Tronche Cedex, France.
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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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Next generation OP-bioscavengers: A circulatory long-lived 4-PEG hypolysine mutant of F338A-HuAChE with optimal pharmacokinetics and pseudo-catalytic characteristics. Chem Biol Interact 2010; 187:253-8. [DOI: 10.1016/j.cbi.2009.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 11/30/2009] [Accepted: 12/02/2009] [Indexed: 11/21/2022]
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Chirality of organophosphorus pesticides: Analysis and toxicity. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:1277-84. [DOI: 10.1016/j.jchromb.2009.11.022] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 11/10/2009] [Accepted: 11/12/2009] [Indexed: 11/16/2022]
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Masson P, Rochu D. Catalytic Bioscavengers Against Toxic Esters, an Alternative Approach for Prophylaxis and Treatments of Poisonings. Acta Naturae 2009. [DOI: 10.32607/20758251-2009-1-1-68-79] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Liang D, Blouet JP, Borrega F, Bon S, Massoulié J. Respective roles of the catalytic domains and C-terminal tail peptides in the oligomerization and secretory trafficking of human acetylcholinesterase and butyrylcholinesterase. FEBS J 2009; 276:94-108. [PMID: 19019080 DOI: 10.1111/j.1742-4658.2008.06756.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Butyrylcholinesterase (BChE) and the T splice variant of acetylcholinesterase that is predominant in mammalian brain and muscles (AChE(T)) possess a characteristic C-terminal tail (t) peptide. This t peptide allows their assembly into tetramers associated with the anchoring proteins ColQ and PRiMA. Although the t peptides of all vertebrate cholinesterases are remarkably similar and, in particular, contain seven strictly conserved aromatic residues, these enzymes differ in some of their oligomerization properties. To explore these differences, we studied human AChE (Aa) and BChE (Bb), and chimeras in which the t peptides (a and b) were exchanged (Ab and Ba). We found that secretion was increased by deletion of the t peptides, and that it was more efficient with a than with b. The patterns of oligomers were similar for Aa and Ab, as well as for Ba and Bb, indicating a predominant influence of the catalytic domains. However, addition of a cysteine within the aromatic-rich segment of the t peptides modified the oligomeric patterns: with a cysteine at position 19, the proportion of tetramers was markedly increased for Aa(S19C) and Ba(S19C), and to a lesser extent for Bb(N19C); the Ab(N19C) mutant produced all oligomeric forms, from monomers to hexamers. These results indicate that both the catalytic domains and the C-terminal t peptides contribute to the capacity of cholinesterases to form and secrete various oligomers. Sequence comparisons show that the differences between the t peptides of AChE and BChE are remarkably conserved among all vertebrates, suggesting that they reflect distinct functional adaptations.
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Affiliation(s)
- Dong Liang
- Laboratoire de Neurobiologie, CNRS UMR 8544, Ecole Normale Supérieure, Paris, France
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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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40
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Duysen EG, Li B, Carlson M, Li YF, Wieseler S, Hinrichs SH, Lockridge O. Increased hepatotoxicity and cardiac fibrosis in cocaine-treated butyrylcholinesterase knockout mice. Basic Clin Pharmacol Toxicol 2008; 103:514-21. [PMID: 19067679 DOI: 10.1111/j.1742-7843.2008.00259.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In mice, cocaine is detoxified to inactive products by butyrylcholinesterase (BChE) and carboxylesterase. In human beings, cocaine detoxification is primarily by BChE. The focus of this investigation was to elucidate the importance of BChE in reducing pathophysiological effects following cocaine exposure. Previous studies examining the effects of cocaine on BChE deficient animals relied on chemical inhibition of BChE with tetraisopropyl pyrophosphoramide (iso-OMPA). The creation of the BChE knockout mouse has provided a model for studying pathological effects of cocaine in mice free of chemical confounders. We hypothesized that mice with low or no BChE activity would have reduced cocaine metabolism, leading to hepatotoxicity and cardiomyopathy. A high-resolution in vivo imaging system recorded cardiac and respiratory function following treatment with a carboxylesterase inhibitor and a high dose of cocaine (100 mg/kg, intraperitoneally). The BChE-/- mice demonstrated depressed respiration through 12 hr after dosing and abnormal respiratory patterns consisting of a pause at full inspiration (apneusis), whereas BChE+/+ mice had recovered normal respiration rates by 30 min. after dosing and exhibited no apneusis. Liver and cardiac histology sections were analysed following a 20 mg/kg intraperitoneally dose of cocaine administered daily for 7 days. BChE-/- mice treated for 7 days with the chronic low dose showed significant hepatotoxicity and cardiac perivascular fibrosis compared to BChE+/+ mice. The observed functional changes following acute high-dose and chronic low-dose cocaine in BChE-/- and +/- mice warrants further investigation into the possibility of increased cocaine toxicity in human beings with BChE deficiency.
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Affiliation(s)
- Ellen G Duysen
- Eppley Institute, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, USA
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Protection of red blood cell acetylcholinesterase by oral huperzine A against ex vivo soman exposure: Next generation prophylaxis and sequestering of acetylcholinesterase over butyrylcholinesterase. Chem Biol Interact 2008; 175:380-6. [DOI: 10.1016/j.cbi.2008.04.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 04/22/2008] [Accepted: 04/23/2008] [Indexed: 11/18/2022]
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Mazor O, Cohen O, Kronman C, Raveh L, Stein D, Ordentlich A, Shafferman A. Aging-resistant organophosphate bioscavenger based on polyethylene glycol-conjugated F338A human acetylcholinesterase. Mol Pharmacol 2008; 74:755-63. [PMID: 18523134 DOI: 10.1124/mol.108.047449] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The high reactivity of cholinesterases (ChEs) toward organophosphorus (OP) compounds has led to propose recombinant ChEs as bioscavengers of nerve agents. The bioscavenging potential of recombinant ChEs can be enhanced by conjugation of polyethylene glycol (PEG) moieties, to extend their circulatory residence. However, the ability of exogenously administered ChEs to confer long-term protection against repeated exposures to nerve agents is still limited due to the aging process, whereby organophosphate-ChE adducts undergo irreversible dealkylation, which precludes oxime-mediated reactivation of the enzyme. To generate an optimal acetylcholinesterase (AChE)-based OP bioscavenger, the F338A mutation, known to decelerate the rate of aging of AChE-OP conjugates, was incorporated into polyethylene glycol-conjugated (PEGylated) human AChE. The PEGylated F338A-AChE displayed unaltered rates of hydrolysis, inhibition, phosphylation, and reactivation and could effectively protect mice against exposure to soman (pinacolylmethyl phosphonofluoridate), sarin (O-isopropyl methylphosphonofluoridate), or O-ethyl-S-(2-isopropylaminoethyl) methylphosphonothioate (VX). Unlike PEGylated wild-type (WT)-AChE, the PEGylated F338A-AChE exhibits significantly reduced aging rates after soman inhibition and can be efficiently reactivated by the 1-[[[4(aminocarbonyl)-pyridinio]methoxy]methyl]-2(hydroxyimino)methyl]pyridinium dichloride (HI-6) oxime, both in vitro and in vivo. Accordingly, oxime administration to PEG-F338A-AChE-pretreated mice enabled them to withstand repeated soman exposure (5.4 and 4 LD(50)/dose), whereas same regime treatment of non-PEGylated F338A-AChE- or PEGylated WT-AChE-pretreated mice failed to protect against the second challenge, due to rapid clearance or irreversible aging of the latter enzymes. Thus, judicious incorporation of selected mutations into the AChE mold in conjunction with its chemical modification provides means to engineer an optimal ChE-based OP bioscavenger in terms of circulatory longevity, resistance to aging, and reduced doses required for protection, even against repeated exposures to nerve agents, such as soman.
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Affiliation(s)
- Ohad Mazor
- Israel Institute for Biological Research, Ness-Ziona 74100, Israel
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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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Cohen O, Kronman C, Lazar A, Velan B, Shafferman A. Controlled Concealment of Exposed Clearance and Immunogenic Domains by Site-specific Polyethylene Glycol Attachment to Acetylcholinesterase Hypolysine Mutants. J Biol Chem 2007; 282:35491-501. [DOI: 10.1074/jbc.m704785200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Shen ZX. Rationale for diagnosing deficiency of ChEs and for applying exogenous HuChEs to the treatment of diseases. Med Hypotheses 2007; 70:43-51. [PMID: 17587508 DOI: 10.1016/j.mehy.2007.04.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Accepted: 04/25/2007] [Indexed: 11/21/2022]
Abstract
Recent evidence strongly demonstrates that acetylcholine (ACh) is not only involved in the function of the central and peripheral nervous systems, including the parasympathetic and somatic systems, but also acts as a ubiquitous cell signaling molecule or cytotransmitter, and as a hormone with paracrine, juxtacrine and autocrine properties. This active molecule exerts versatile and potent functions primarily through its specific nicotinic and muscarinic receptors (nAChRs and mAChRs, respectively). These functions modulate numerous biomechanisms, including cell growth, survival, proliferation and differentiation, cell-cell contact, cell cycle, locomotion, electrical activity, immune function, apoptosis, organization of the cytoskeleton, trophic functions, secretion, adhesion, resorption, and stress-response-regulation. By nature, the precise ACh levels and responses from receptors must be controlled and regulated by its degrading enzymes, the cholinesterases (ChEs), namely, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Once ChEs become critically deficient in quality and quantity, ACh signaling will be uncontrollably aberrant and persistent. An in-depth account of the fundamental roles of ChEs, comprising their diverse soluble and membrane-bound forms, in maintaining the functional equilibrium of ACh in the macro and microenvironment has been undertaken. This work also covers ACh receptors, signaling pathways, other interdependent and interrelated substances, functional processes, role of ChEs as first-line gatekeepers and defenses for the architecture of cells, tissues and organisms, physically, chemically, and structurally. The mechanisms of many diseases ranging from the acute cholinergic crisis to the chronic degenerative and hypergenerative disorders such as Alzheimer's disease, cancers, atopic dermatitis, may involve a deficiency of ChEs or imbalance between ACh and ChEs, initially or consequentially. It is therefore essential to ascertain a ChE deficiency, or an imbalance between ACh and ChEs, in tissues and body fluids in order for conducting clinical diagnosis, prevention and treatment. An argument is put forward on the rationale of applying exogenous human ChEs to reverse enzymatic deficiency and correct the imbalance between ACh and ChEs, to repair the affected receptors and protect against their further loss in the body, and consequently to alleviate the signs and symptoms of diseases. Evidence is adduced for the safety and efficacy of ChEs treatment.
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Kronman C, Cohen O, Raveh L, Mazor O, Ordentlich A, Shafferman A. Polyethylene-glycol conjugated recombinant human acetylcholinesterase serves as an efficacious bioscavenger against soman intoxication. Toxicology 2007; 233:40-6. [PMID: 17045722 DOI: 10.1016/j.tox.2006.08.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 08/27/2006] [Accepted: 08/28/2006] [Indexed: 10/24/2022]
Abstract
Extensive pharmacokinetic studies in both mice and rhesus macaques, with biochemically well defined forms of native and recombinant AChEs from bovine, rhesus and human origin, allowed us to determine an hierarchical pattern by which post-translation-related factors and specific amino-acid epitopes govern the pharmacokinetic performance of the enzyme molecule. In parallel, we demonstrated that controlled conjugation of polyethylene-glycol (PEG) side-chains to lysine residues of rHuAChE also results in the generation of active enzyme with improved pharmacokinetic performance. Here, we show that equally efficient extension of circulatory residence can be achieved by specific conditions of PEGylation, regardless of the post-translation-modification state of the enzyme. The masking effect of PEGylation, which is responsible for extending circulatory lifetime, also contributes to the elimination of immunological responses following repeated administration of AChE. Finally, in vivo protection studies in mice allowed us to determine that the PEGylated AChE protects the animal from a high lethal dose (2.5 LD(50)) of soman. On a mole basis, both the recombinant AChE and its PEGylated form provide higher levels of protection against soman poisoning than the native serum-derived HuBChE. The findings that circulatory long-lived PEGylated AChE can confer superior protection to mice against OP-compound poisoning while exhibiting reduced immunogenicity, suggest that this chemically modified version of rHuAChE may serve as a highly effective bioscavenger for prophylactic treatment against OP-poisoning.
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Affiliation(s)
- Chanoch Kronman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 74100, Israel
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