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Wang J, Lu X, Gao R, Pei C, Wang H. Progressive expansion of albumin adducts for organophosphorus nerve agent traceability based on single and group adduct collection. Anal Bioanal Chem 2024; 416:3569-3584. [PMID: 38698257 DOI: 10.1007/s00216-024-05311-y] [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: 03/04/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 05/05/2024]
Abstract
Protein adducts are important biological targets for traceability of organophosphorus nerve agents (OPNAs). Currently, the recognized biomarkers that can be used in actual samples in the field of chemical forensics only include Y411 in albumin and the active nonapeptide in butyrylcholinesterase (BChE). To explore stable and reliable protein adducts and increase the accuracy of OPNAs traceability further, we gradually expanded OPNAs-albumin adducts based on single and group adduct collection. Several stable peptides were found via LC-MS/MS analysis in human serum albumin (HSA) exposed to OPNAs in a large exposure range. These adducts were present in HSA samples exposed to OPNAs of each concentration, which provided data support for the reliability and stability of using adducts to trace OPNAs. Meanwhile, the formation mechanism of OPNAs-cysteine adduct was clarified via computer simulations. Then, these active sites found and modified peptides were used as raw materials for progressive expansion of albumin adducts. We constructed an OPNAs-HSA adducts group, in which a specific agent is the exposure source, and three or more active peptides constitute data sets for OPNAs traceability. Compared with single or scattered protein adducts, the OPNAs-HSA adduct group improves OPNAs identification by mutual verification using active peptides or by narrowing the identity range of the exposure source. We also determined the minimum detectable concentration of OPNAs for the adduct group. Two or more peptides can be detected when there is an exposure of 50 times the molar excess of OPNAs in relation to HSA. This improved the accuracy of OPNAs exposure and identity confirmation. A collection of OPNAs-albumin adducts was also examined. The collection was established by collecting, classifying, and integrating the existing albumin adducts according to the species to which each albumin belongs, the types of agents, and protease. This method can serve as a reference for discovering new albumin adducts, characteristic phosphonylated peptides, and potential biomarkers. In addition, to avoid a false negative for OPNAs traceability using albumin adducts, we explored OPNAs-cholinesterase adducts because cholinesterase is more reactive with OPNAs than albumin. Seven active peptides in red blood cell acetylcholinesterase (RBC AChE) and serum BChE can assist in OPNAs exposure and identity confirmation.
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Affiliation(s)
- Jin Wang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Xiaogang Lu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Runli Gao
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Chengxin Pei
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Hongmei Wang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
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2
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Xing M, Wang S, Cui F, Liu H, Zhang X, Gao Z, Ying W, Shi E. Comprehensive insight on protein modification by V-type agent: A chemical proteomic approach employing bioorthogonal reaction. Proteomics 2024; 24:e2300039. [PMID: 37654063 DOI: 10.1002/pmic.202300039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/21/2023] [Accepted: 07/12/2023] [Indexed: 09/02/2023]
Abstract
Organophosphorus compounds (OPs) such as chemical agents and pesticides are posing critical threats to civilians due to their irreversible phosphonylation of diverse amino acids residues forming different protein adducts. However, traditional analytical approaches are quite limited in capturing the myriad of post-translational events that affect protein functions, especially in identifying the low-abundance OP adducts. Herein a systematic proteomic strategy based on a typical click-enrich-release-identify bioorthogonal operation was firstly developed by employing an alkynyl-tagged V-type agent probe (AVP) and a biotin-based azido-enrichment linker (BTP-N3 ). AVP targeting peptides from human serum albumin (HSA) or plasma were captured by BTP-N3 via CuAAC click reaction, enriched by streptavidin beads, released by selective alkaline hydrolysis of phenacyl ester bond, and subsequently sequenced by LC-MS/MS. This strategy has helped identifying 1115 unique OP adduction sites on 163 proteins in human plasma, and covers lots of OP adducts that cannot be achieved by traditional detection methods. The comprehensive coverage of novel OP substrates provided a general and sensitive approach to retrospective verification and/or dose assessment of toxic OPs.
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Affiliation(s)
- Meining Xing
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (Beijing), Beijing, China
| | - Shuo Wang
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Fangfang Cui
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (Beijing), Beijing, China
| | - Haibo Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Xiangye Zhang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (Beijing), Beijing, China
| | - Zhenhua Gao
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
| | - Wantao Ying
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Lifeomics, National Center for Protein Sciences (Beijing), Beijing, China
| | - Enxue Shi
- State Key Laboratory of NBC Protection for Civilian, Beijing, China
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3
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Palermo G, Kovarik Z, Hotchkiss PJ. Newly scheduled carbamate compounds: A synopsis of their properties and development, and considerations for the scientific community. Toxicology 2022; 480:153322. [PMID: 36115648 DOI: 10.1016/j.tox.2022.153322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/07/2022] [Accepted: 09/12/2022] [Indexed: 11/28/2022]
Abstract
In November 2019, for the first time in the history of the Chemical Weapons Convention, changes were made to Schedule 1 of the Annex on Chemicals. While there is little in the scientific literature regarding any of these newly scheduled chemicals, the carbamates, specifically, prove to be substantially different, both in terms of their chemical composition and their toxicological effects, from all the other scheduled nerve agents and have yet to be fully reported on in the literature. Herein, we present a literature review of the available information on carbamates included in Schedule 1, as well as analogous other carbamates, and provide a summary of their utility and function as cholinesterase inhibitors in general and their toxicities. Though there is a paucity of studies in the literature related to the detection of these newly scheduled quaternary and bisquaternary carbamates and/or their biomarkers, information available on carbamate pesticides may be a solid starting point to further postulate amenable detection methodologies. Lastly, we note some implications of these newly scheduled carbamates for the nonproliferation and disarmament community.
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Affiliation(s)
- Giulia Palermo
- Organisation for the Prohibition of Chemical Weapons, Office of Strategy and Policy Intern, The Hague, the Netherlands
| | - Zrinka Kovarik
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000 Zagreb, Croatia
| | - Peter J Hotchkiss
- Organisation for the Prohibition of Chemical Weapons, The Hague, the Netherlands.
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Retrospective detection for V-type OPNAs exposure via phosphonylation and disulfide adducts in albumin. Sci Rep 2022; 12:10979. [PMID: 35768567 PMCID: PMC9243071 DOI: 10.1038/s41598-022-15198-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/20/2022] [Indexed: 11/08/2022] Open
Abstract
Organophosphorus nerve agents (OPNAs) that damage the central nervous system by inhibiting acetylcholinesterase activity, pose severe threats to human health and life security. Reliable biomarkers that quickly and accurately detect OPNAs exposure are urgently needed to help diagnose quickly and treat in time. Albumins that covalently bind to OPNAs could serve as important targets for retrospective verification of OPNAs exposure. The goal of this study is to explore the potential biomarkers in albumins with high reactivity and good stability and expand the group of potential biomarkers in different species for detecting the exposure of V-type OPNAs including O-ethyl S-(2-(diisopropylamino)ethyl) methylphosphonothioate (VX), O-isobutyl S-(2(diethylamino)ethyl) methylphosphonothioate (VR), and O-butyl S-(2-(diethylamino)ethyl) methylphosphonothioate (Vs). Taking human serum albumin (HSA), bovine serum albumin (BSA) and rabbit serum albumin (RSA) as the research objectives, multiple active sites including phosphonylation and disulfide adduct sites were observed in albumins from different species. Numerous phosphonylation sites labeled by all agents in one type of albumin were found. Among the different species, four shared phosphonylation sites with high reactivity include K499, K549, K249, and Y108. In addition, Y108 on ETY*GEMADCCAK, Y287 on Y*ICENQDSISSK, Y377 on TY*ETTLEK and Y164 on YLY*EIAR in HSA were stably phosphonylated by all agents in gradient concentration, making them stable and suitable potential biomarkers for V-type OPNAs exposure. Notably, Y108 on ETY*GEMADCCAK in HSA, on DTY*GDVADCCEK in RSA, and on ETY*GDMADCCEK in BSA were highly reactive to all V-type agents, regardless of species. It was also successfully labeled in HSA exposed to class V agents in gradient concentration. Y108 is expected to be used to screen and identify the exposure of V-type agents in the retrospective research. Disulfide adducts sites, consisted of four sites in HSA and two sites in BSA were also successfully labeled by V-type agents, and characteristic ion fragments from these disulfide adducts were also identified by secondary mass spectrometry. Molecular simulation of the stably modified sites were conducted to discover the promoting factors of covalent adduct formation, which help further clarify formation mechanism of albumin adducts at active sites.
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Braun AV, Vokuev MF, Stavitskaya YV, Baygildiev TM, Yashkir VA, Rybalchenko IV, Rodin IA. Characteristics of a High-Resolution Mass Spectrum of an Adduct of 2-(Diethylamino)Ethylthiol with a Dipeptide (Cys–Pro). JOURNAL OF ANALYTICAL CHEMISTRY 2021. [DOI: 10.1134/s1061934821140021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Baygildiev ТМ, Vokuev MF, Braun AV, Yashkir VA, Rуbalchenko IV, Rodin IA. Identification of 2-(diethylamino)ethylthiol dipeptide (Cys-Pro) adduct as biomarker of nerve agents VR and CVX in human plasma using liquid chromatography-high-resolution tandem mass spectrometry. Anal Bioanal Chem 2021; 413:1905-1916. [PMID: 33479815 DOI: 10.1007/s00216-021-03158-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/29/2020] [Accepted: 01/05/2021] [Indexed: 12/28/2022]
Abstract
Organophosphorus nerve agents pose a significant threat to human health. The most toxic compounds in this class include V-type poisonous substances such as VX, CVX, and VR. Although all stockpiles of this type of substance are subject to destruction under the Chemical Weapons Convention (CWC), there is still a risk that they could be used for criminal and terrorist purposes. The latter determines the relevance of studies aimed at identification of biomarkers that may indicate the exposure of these group substances to the organism. A liquid chromatography mass spectrometry/high-resolution mass spectrometry (LC-MS/HR MS) method for determination of trace amounts of nerve agents such as VR and CVX in human plasma was proposed. The method is based on enzymatic plasma hydrolysis with the use of pronase to form a stable adduct of 2-(diethylamino)ethylthiol with dipeptide cysteine-proline (DEAET-CP) with its subsequent determination by LC-MS/HR MS. Synthesis of DEAET-CP as reference compound was conducted using non-toxic precursors. Sample preparation of human blood plasma samples exposed to VR was carried out with the use of solid-phase extraction (SPE). Liquid chromatography (LC) separation on the reversed-phase column and mass spectrometric detection (selection of optimal transitions and detection modes) were performed. The achieved limit of detection (LOD) of VR (in the form of DEAET-CP) in human blood plasma was 0.05 ng mL-1. The proposed approach was developed using plasma samples exposed to VR and CVX obtained in the frame of the Fifth Official Biomedical Test of the Organization for the Prohibition of Chemical Weapons (OPCW) and showed good specificity of detection.
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Affiliation(s)
- Тimur М Baygildiev
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Mikhail F Vokuev
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, 119991.
| | - Arkady V Braun
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, 119991
- Laboratory for the Chemical and Analytical Control of the Military Research Centre, Moscow, Russia, 105005
| | - Vadim A Yashkir
- Laboratory for the Chemical and Analytical Control of the Military Research Centre, Moscow, Russia, 105005
| | - Igor V Rуbalchenko
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, 119991
- Laboratory for the Chemical and Analytical Control of the Military Research Centre, Moscow, Russia, 105005
| | - Igor A Rodin
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia, 119991
- Department of Epidemiology and Evidence Based Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia, 119435
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7
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Fu F, Liu H, Gao R, Zhao P, Lu X, Zhang R, Wang L, Wang H, Pei C. Protein adduct binding properties of tabun-subtype nerve agents after exposure in vitro and in vivo. Toxicol Lett 2020; 321:1-11. [DOI: 10.1016/j.toxlet.2019.12.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/09/2019] [Accepted: 12/13/2019] [Indexed: 12/15/2022]
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Fu F, Sun F, Lu X, Song T, Ding J, Gao R, Wang H, Pei C. A Novel Potential Biomarker on Y263 Site in Human Serum Albumin Poisoned by Six Nerve Agents. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1104:168-175. [DOI: 10.1016/j.jchromb.2018.11.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/09/2018] [Accepted: 11/08/2018] [Indexed: 01/24/2023]
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9
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Timperley CM, Forman JE, Abdollahi M, Al-Amri AS, Alonso IP, Baulig A, Borrett V, Cariño FA, Curty C, Berrutti DG, Kovarik Z, Martínez-Álvarez R, Mikulak R, Mourão NMF, Ponnadurai R, Neffe S, Raza SK, Rubaylo V, Takeuchi K, Tang C, Trifirò F, van Straten FM, Vanninen PS, Zaitsev V, Waqar F, Zina MS, Blum MM, Gregg H, Fischer E, Sun S, Yang P. Advice on chemical weapons sample stability and storage provided by the Scientific Advisory Board of the Organisation for the Prohibition of Chemical Weapons to increase investigative capabilities worldwide. Talanta 2018; 188:808-832. [DOI: 10.1016/j.talanta.2018.04.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 04/03/2018] [Accepted: 04/07/2018] [Indexed: 01/12/2023]
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Onder S, Schopfer LM, Tacal O, Blake TA, Johnson RC, Lockridge O. Mass Spectral Detection of Diethoxyphospho-Tyrosine Adducts on Proteins from HEK293 Cells Using Monoclonal Antibody depY for Enrichment. Chem Res Toxicol 2018; 31:520-530. [PMID: 29775289 PMCID: PMC6008731 DOI: 10.1021/acs.chemrestox.8b00083] [Citation(s) in RCA: 12] [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
![]()
Chronic illness from exposure to
organophosphorus toxicants is
hypothesized to involve modification of unknown proteins. Tyrosine
in proteins that have no active site serine readily reacts with organophosphorus
toxicants. We developed a monoclonal antibody, depY, that specifically
recognizes diethoxyphospho-tyrosine in proteins and peptides, independent
of the surrounding amino acid sequence. Our goal in the current study
was to identify diethoxyphosphorylated proteins in human HEK293 cell
lysate treated with chlorpyrifos oxon. Cell lysates treated with chlorpyrifos
oxon were recognized by depY antibody in ELISA and capillary electrophoresis
based Western blot. Tryptic peptides were analyzed by liquid chromatography
tandem mass spectrometry. Liquid chromatography tandem mass spectrometry
identified 116 diethoxyphospho-tyrosine peptides from 73 proteins
in immunopurified samples, but found only 15 diethoxyphospho-tyrosine
peptides from 12 proteins when the same sample was not immunopurified
on depY. The most abundant proteins in the cell lysate, histone H4,
heat shock 70 kDa protein 1A/1B, heat shock protein HSP 90 β,
and α-enolase, were represented by several diethoxyphospho-tyrosine
peptides. It was concluded that use of immobilized depY improved the
number of diethoxyphospho-tyrosine peptides identified in a complex
mixture. The mass spectrometry results confirmed the specificity of
depY for diethoxyphospho-tyrosine peptides independent of the context
of the modified tyrosine, which means depY could be used to analyze
modified proteins in any species. Use of the depY antibody could lead
to an understanding of chronic illness from organophosphorus pesticide
exposure.
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Affiliation(s)
- Seda Onder
- Department of Biochemistry, School of Pharmacy , Hacettepe University , Ankara 06100 , Turkey.,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
| | - Ozden Tacal
- Department of Biochemistry, School of Pharmacy , Hacettepe University , Ankara 06100 , Turkey
| | - Thomas A Blake
- Division of Laboratory Sciences, National Center for Environmental Health , Centers for Disease Control and Prevention , 4770 Buford Highway NE , Atlanta , Georgia 30341 , United States
| | - Rudolph C Johnson
- Division of Laboratory Sciences, National Center for Environmental Health , Centers for Disease Control and Prevention , 4770 Buford Highway NE , Atlanta , Georgia 30341 , United States
| | - Oksana Lockridge
- Eppley Institute , University of Nebraska Medical Center , Omaha , Nebraska 68198 , United States
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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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12
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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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Macdonald IR, Reid GA, Pottie IR, Martin E, Darvesh S. Synthesis and Preliminary Evaluation of Phenyl 4-123I-Iodophenylcarbamate for Visualization of Cholinesterases Associated with Alzheimer Disease Pathology. J Nucl Med 2015; 57:297-302. [PMID: 26541777 DOI: 10.2967/jnumed.115.162032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 10/21/2015] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Acetylcholinesterase and butyrylcholinesterase accumulate with brain β-amyloid (Aβ) plaques in Alzheimer disease (AD). The overall activity of acetylcholinesterase is found to decline in AD, whereas butyrylcholinesterase has been found to either increase or remain the same. Although some cognitively normal older adults also have Aβ plaques within the brain, cholinesterase-associated plaques are generally less abundant in such individuals. Thus, brain imaging of cholinesterase activity associated with Aβ plaques has the potential to distinguish AD from cognitively normal older adults, with or without Aβ accumulation, during life. Current Aβ imaging agents are not able to provide this distinction. To address this unmet need, synthesis and evaluation of a cholinesterase-binding ligand, phenyl 4-(123)I-iodophenylcarbamate ((123)I-PIP), is described. METHODS Phenyl 4-iodophenylcarbamate was synthesized and evaluated for binding potency toward acetylcholinesterase and butyrylcholinesterase using enzyme kinetic analysis. This compound was subsequently rapidly radiolabeled with (123)I and purified by high-performance liquid chromatography. Autoradiographic analyses were performed with (123)I-PIP using postmortem orbitofrontal cortex from cognitively normal and AD human brains. Comparisons were made with an Aβ imaging agent, 2-(4'-dimethylaminophenyl)-6-(123)I-iodo-imidazo[1,2-a]pyridine ((123)I-IMPY), in adjacent brain sections. Tissues were also stained for Aβ and cholinesterase activity to visualize Aβ plaque load for comparison with radioligand uptake. RESULTS Synthesized and purified PIP exhibited binding to cholinesterases. (123)I was successfully incorporated into this ligand. (123)I-PIP autoradiography with human tissue revealed accumulation of radioactivity only in AD brain tissues in which Aβ plaques had cholinesterase activity. (123)I-IMPY accumulated in brain tissues with Aβ plaques from both AD and cognitively normal individuals. CONCLUSION Radiolabeled ligands specific for cholinesterases have potential for use in neuroimaging AD plaques during life. The compound herein described, (123)I-PIP, can detect cholinesterases associated with Aβ plaques and can distinguish AD brain tissues from those of cognitively normal older adults with Aβ plaques. Imaging cholinesterase activity associated with Aβ plaques in the living brain may contribute to the definitive diagnosis of AD during life.
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Affiliation(s)
- Ian R Macdonald
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - G Andrew Reid
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ian R Pottie
- Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, Nova Scotia, Canada Department of Chemistry, Saint Mary's University, Halifax, Nova Scotia, Canada; and
| | - Earl Martin
- Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, Nova Scotia, Canada
| | - Sultan Darvesh
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, Nova Scotia, Canada Department of Medicine (Neurology and Geriatric Medicine), Dalhousie University, Halifax, Nova Scotia, Canada
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14
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Black RM, Read RW. Biological markers of exposure to organophosphorus nerve agents. Arch Toxicol 2013; 87:421-37. [DOI: 10.1007/s00204-012-1005-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 12/18/2012] [Indexed: 11/28/2022]
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16
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Abstract
Diagnosis of nerve agent intoxication is based on anamnestic data, clinical signs and laboratory examination. For acute poisoning, cholinesterase activity in the blood (erythrocyte AChE, plasma/serum BuChE) is sensitive, simple and most frequent laboratory examination performed in biochemical laboratories. Specialized examinations to precise treatment (reactivation test) or to make retrospective diagnosis (fluoride induced reactivation etc.) can be conducted. Other sophisticated methods are available, too.
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Affiliation(s)
- Jirí Bajgar
- University of Defence, Department of Toxicology, Faculty of Military Health Sciences, Hradec Králové, Czech Republic.
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Marsillach J, Hsieh EJ, Richter RJ, MacCoss MJ, Furlong CE. Proteomic analysis of adducted butyrylcholinesterase for biomonitoring organophosphorus exposures. Chem Biol Interact 2012; 203:85-90. [PMID: 23123252 DOI: 10.1016/j.cbi.2012.10.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/09/2012] [Accepted: 10/09/2012] [Indexed: 10/27/2022]
Abstract
Organophosphorus (OP) compounds include a broad group of toxic chemicals such as insecticides, chemical warfare agents and antiwear agents. The liver cytochromes P450 bioactivate many OPs to potent inhibitors of serine hydrolases. Cholinesterases were the first OP targets discovered and are the most studied. They are used to monitor human exposures to OP compounds. However, the assay that is currently used has limitations. The mechanism of action of OP compounds is the inhibition of serine hydrolases by covalently modifying their active-site serine. After structural rearrangement, the complex OP inhibitor-enzyme is irreversible and will remain in circulation until the modified enzyme is degraded. Mass spectrometry is a sensitive technology for analyzing protein modifications, such as OP-adducted enzymes. These analyses also provide some information about the nature of the OP adduct. Our aim is to develop high-throughput protocols for monitoring OP exposures using mass spectrometry.
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Affiliation(s)
- Judit Marsillach
- Dept of Medicine (Division of Medical Genetics), University of Washington, 98195 Seattle, WA, USA.
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Jiang W, Duysen EG, Lockridge O. Mice treated with a nontoxic dose of chlorpyrifos oxon have diethoxyphosphotyrosine labeled proteins in blood up to 4 days post exposure, detected by mass spectrometry. Toxicology 2012; 295:15-22. [PMID: 22406659 DOI: 10.1016/j.tox.2012.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 02/28/2012] [Accepted: 03/01/2012] [Indexed: 11/18/2022]
Abstract
Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity is an established biomarker of exposure to organophosphorus poisons (OP). Inhibition of activity is due to covalent binding of the OP to the active site serine. Mass spectrometry has made it possible to monitor OP exposure by analyzing OP adducts on tyrosine in proteins that have no active site serine. Our goal was to test the hypothesis that OP-tyrosine may serve as a biomarker of OP exposure in mice. A MALDI-TOF mass spectrometry strategy to analyze diethoxyphosphate-tyrosine of m/z 318 was developed. The adduct was synthesized by incubating l-tyrosine with chlorpyrifos oxon at pH 8.1. The adduct eluted from a reverse phase HPLC column with 22-23% acetonitrile. The fragmentation spectrum of the m/z 318 precursor ion confirmed its identity as diethoxyphosphate-tyrosine. Diethoxyphosphate-tyrosine was isolated from chlorpyrifos oxon treated mouse albumin after digesting the protein with pronase. Mice (n=3 per group) were treated with a nontoxic dose of chlorpyrifos oxon (3 mg/kg) and a toxic dose (10 mg/kg transdermally). The pronase digested plasma yielded diethoxyphosphate-tyrosine up to 120 h after treatment with 3 mg/kg chlorpyrifos oxon and up to 144 h after 10 mg/kg. In contrast plasma AChE activity returned to normal after 24-72 h. In conclusion MALDI-TOF mass spectrometry can be used to diagnose exposure to chlorpyrifos oxon days after AChE inhibition assays are uninformative.
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Affiliation(s)
- Wei Jiang
- Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE 68198-5950, United States.
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John H, Blum MM. Editorial: Analysis of drugs for the therapy of anticholinesterase poisoning. Drug Test Anal 2012; 4:167-8. [DOI: 10.1002/dta.412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Harald John
- Bundeswehr Institute of Pharmacology and Toxicology; Munich; Germany
| | - Marc-Michael Blum
- Los Alamos National Laboratory; Bioscience Division; Los Alamos; NM; USA; LA-UR 12-00299
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