1
|
Kranawetvogl T, Siegert M, Steinritz D, Thiermann H, John H. The phosphylated butyrylcholinesterase-derived tetrapeptide GlyGluSerAla proves exposure to organophosphorus agents with enantioselectivity. Arch Toxicol 2024; 98:791-806. [PMID: 38267661 DOI: 10.1007/s00204-023-03657-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 12/04/2023] [Indexed: 01/26/2024]
Abstract
We herein present for the first time the phosphylated (*) tetrapeptide (TP)-adduct GlyGluSer198*Ala generated from butyrylcholinesterase (BChE) with proteinase K excellently suited for the verification of exposure to toxic organophosphorus nerve agents (OPNA). Verification requires bioanalytical methods mandatory for toxicological and legal reasons. OPNA react with BChE by phosphonylation of the active site serine residue (Ser198) forming one of the major target protein adducts for verification. After its enzymatic cleavage with pepsin, the nonapeptide (NP) PheGlyGluSer*AlaGlyAlaAlaSer is typically produced as biomarker. Usually OPNA occur as racemic mixtures of phosphonic acid derivatives with the stereocenter at the phosphorus atom, e.g. (±)-VX. Both enantiomers react with BChE, but the adducted NP does not allow their chromatographic distinction. In contrast, the herein introduced TP-adducts appeared as two peaks when using a stationary reversed phase (1.8 µm) in micro-liquid chromatography-electrospray ionisation tandem-mass spectrometry (µLC-ESI MS/MS) analysis. These two peaks represent diastereomers of the (+)- and (-)-OPNA adducted to the peptide that comprises chiral L-amino acids exclusively. Concentration- and time-dependent effects of adduct formation with (±)-VX and its pure enantiomers (+)- and (-)-VX as well as with (±)-cyclosarin (GF) were investigated in detail characterising enantioselective adduct formation, stability, ageing and spontaneous reactivation. The method was also successfully applied to samples from a real case of pesticide poisoning as well as to samples of biomedical proficiency tests provided by the Organisation for the Prohibition of Chemical Weapons.
Collapse
Affiliation(s)
- Tamara Kranawetvogl
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937, Munich, Germany
- Walther-Straub-Institut, Ludwig-Maximilians-Universität, Munich, Germany
| | - Markus Siegert
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937, Munich, Germany
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937, Munich, Germany
- Walther-Straub-Institut, Ludwig-Maximilians-Universität, Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937, Munich, Germany
| | - Harald John
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937, Munich, Germany.
| |
Collapse
|
2
|
Lv Q, Jiang PY, Xia JM, Liang LH, Chen B, Yang Y, Yan L, Yu HL, Liu CC. Discriminative detection of soman or VX exposure using europium chelated microparticle-based immunofluorescence microfluidic chip. Anal Biochem 2024; 685:115388. [PMID: 37967783 DOI: 10.1016/j.ab.2023.115388] [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: 07/02/2023] [Revised: 10/26/2023] [Accepted: 11/05/2023] [Indexed: 11/17/2023]
Abstract
The retrospective detection of organophosphorus nerve agents (OPNAs) exposure has been achieved by the off-site analysis of OPNA-human serum albumin (HSA) adducts using mass spectrometry-based detection approaches. However, few specific methods are accessible for on-site detection. To address this, a novel immunofluorescence microfluidic chip (IFMC) testing system combining europium chelated microparticle (EuCM) with self-driven microfluidic chip assay has been established to unambiguously determine soman (GD) and VX exposure within 20 min, respectively. The detection system was based on the principle of indirect competitive enzyme-linked immunosorbent assay. The specific monoclonal antibodies that respectively recognized the phosphonylated tyrosine 411 of GD-HSA and VX-HSA adducts were labeled by EuCM to capture corresponding adducts in the exposed samples. The phosphonylated peptides in the test line and goat-anti-rabbit antibody in the control line were utilized to bind the EuCM-labeled antibodies for signal exhibition. The developed IFMC chip could discriminatively detect exposed HSA adducts with high specificity, demonstrating a low limit of detection at exposure concentrations of 0.5 × 10-6 mol/L VX and 1.0 × 10-6 mol/L GD. The exposed serum samples can be qualitatively detected following an additional pretreatment procedure. This is a novel rapid detection system capable of discriminating GD and VX exposure, providing an alternative method for rapidly identifying OPNA exposure.
Collapse
Affiliation(s)
- Qiao Lv
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Pei-Yu Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Jun-Mei Xia
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Long-Hui Liang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Bo Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Yang Yang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Long Yan
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Hui-Lan Yu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
| | - Chang-Cai Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
| |
Collapse
|
3
|
Kranawetvogl T, Kranawetvogl A, Scheidegger L, Wille T, Steinritz D, Worek F, Thiermann H, John H. Evidence of nerve agent VX exposure in rat plasma by detection of albumin-adducts in vitro and in vivo. Arch Toxicol 2023; 97:1873-1885. [PMID: 37264164 PMCID: PMC10256656 DOI: 10.1007/s00204-023-03521-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 05/11/2023] [Indexed: 06/03/2023]
Abstract
VX is a highly toxic organophosphorus nerve agent that reacts with a variety of endogenous proteins such as serum albumin under formation of adducts that can be targeted by analytical methods for biomedical verification of exposure. Albumin is phosphonylated by the ethyl methylphosphonic acid moiety (EMP) of VX at various tyrosine residues. Additionally, the released leaving group of VX, 2-(diisopropylamino)ethanethiol (DPAET), may react with cysteine residues in diverse proteins. We developed and validated a microbore liquid chromatography-electrospray ionization high-resolution tandem mass spectrometry (µLC-ESI MS/HR MS) method enabling simultaneous detection of three albumin-derived biomarkers for the analysis of rat plasma. After pronase-catalyzed cleavage of rat plasma proteins single phosphonylated tyrosine residues (Tyr-EMP), the Cys34(-DPAET)Pro dipeptide as well as the rat-specific LeuProCys448(-DPAET) tripeptide were obtained. The time-dependent adduct formation in rat plasma was investigated in vitro and biomarker formation during proteolysis was optimized. Biomarkers were shown to be stable for a minimum of four freeze-and-thaw cycles and for at least 24 h in the autosampler at 15 °C thus making the adducts highly suited for bioanalysis. Cys34(-DPAET)Pro was superior compared to the other serum biomarkers considering the limit of identification and stability in plasma at 37 °C. For the first time, Cys34(-DPAET)Pro was detected in in vivo specimens showing a time-dependent concentration increase after subcutaneous exposure of rats underlining the benefit of the dipeptide disulfide biomarker for sensitive analysis.
Collapse
Affiliation(s)
- Tamara Kranawetvogl
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
- Walther-Straub-Institut, Ludwig-Maximilians-Universität, Munich, Germany
| | | | - Lisa Scheidegger
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
| | - Timo Wille
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
- Walther-Straub-Institut, Ludwig-Maximilians-Universität, Munich, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
| | - Harald John
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany
| |
Collapse
|
4
|
Muñoz-Torrero D, Schopfer LM, Lockridge O. Chlorpyrifos Oxon Activates Glutamate and Lysine for Protein Cross-linking. Chem Res Toxicol 2023; 36:112-121. [PMID: 36598934 PMCID: PMC9846825 DOI: 10.1021/acs.chemrestox.2c00333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chronic low-dose exposure to organophosphorus (OP) toxicants is correlated with an increase in the risk of impaired cognition and neurodegenerative diseases. A mechanism to explain this relationship is needed. We suggest that the formation of organophosphate-induced high-molecular-weight protein aggregates that disrupt cell function may be the missing link. It has been demonstrated that such aggregation can be promoted by OP-labeled lysine. Alternatively, OP-labeled glutamate may be the initiator. To test this hypothesis, we treated MAP-rich tubulin Sus scrofa and human transglutaminase with chlorpyrifos oxon. Trypsin-digested proteins were subjected to liquid chromatography-tandem mass spectrometry followed by Protein Prospector searches to identify diethyl phosphate adducts and cross-linked peptides. We report the presence of diethyl phosphate adducts on the side chains of glutamate, lysine, and tyrosine, as well as cross-links between glutamate and lysine. Glutamate-lysine cross-linking could be initiated either by diethyl phosphate-activated glutamate or by diethyl phosphate-activated lysine to form stable isopeptide bonds between and within proteins. It was concluded that organophosphate-induced high-molecular-weight protein aggregates could promote brain dysfunction.
Collapse
Affiliation(s)
- Diego Muñoz-Torrero
- Laboratory
of Medicinal Chemistry (CSIC Associated Unit), Faculty of Pharmacy
and Food Sciences, and Institute of Biomedicine (IBUB), University of Barcelona, Barcelona 08028, Spain
| | | | - Oksana Lockridge
- University
of Nebraska Medical Center, Omaha, Nebraska 68198, United States,. Phone +1-402-559-6032.
Fax: +1 402-559-4651
| |
Collapse
|
5
|
Mohammad HB, Park JH, Lee JH, Vu MH, Lee J, Jeong W, Kim M. Comprehensive identification of
VX
‐adducted plasma proteins using high‐resolution mass spectrometry. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hazara Begum Mohammad
- Department of New Biology Daegu Gyeongbuk Institute of Science and Technology Daegu Republic of Korea
| | - Ji Hwan Park
- Department of New Biology Daegu Gyeongbuk Institute of Science and Technology Daegu Republic of Korea
| | - Jun Hyung Lee
- Department of New Biology Daegu Gyeongbuk Institute of Science and Technology Daegu Republic of Korea
| | - Minh Hung Vu
- Department of New Biology Daegu Gyeongbuk Institute of Science and Technology Daegu Republic of Korea
| | - Jin‐Young Lee
- Chem‐Bio Technology Center Agency for Defense Development Daejeon Republic of Korea
| | - Woo‐Hyeon Jeong
- Chem‐Bio Technology Center Agency for Defense Development Daejeon Republic of Korea
| | - Min‐Sik Kim
- Department of New Biology Daegu Gyeongbuk Institute of Science and Technology Daegu Republic of Korea
| |
Collapse
|
6
|
Lv Q, Yu HL, Yang Y, Meng FH, Dai XD, Jiang PY, Liu CC. Screening of monoclonal antibodies against specific phosphonylation sites and analysis of serum samples exposed to soman and VX using an indirect competitive enzyme-linked immunosorbent assay. Anal Bioanal Chem 2022; 414:2713-2724. [PMID: 35083511 DOI: 10.1007/s00216-022-03914-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 12/13/2022]
Abstract
Organophosphorus nerve agents (OPNAs) covalently bind to tyrosine 411 of human serum albumin (HSA) and the formed adducts are stable biomarkers of OPNA exposure. The detection of these adducts has been limited to mass spectrometry techniques combined with protein digestion. Here, we developed indirect competitive ELISA (icELISA) methods to verify OPNA exposure by the detection of OPNA-phosphonylated adducts at tyrosine 411 residue (OPNA-HSA adducts), in which monoclonal antibodies (mAbs) against phosphonylation sites at tyrosine 411 were introduced. The two mAbs were prepared by the fourth generation of rabbit mAb technology using the phosphonylated peptides of LVRY(GD or VX)TKKVPQC as the haptens. These mAbs were screened using our developed competitive ELISA method and then selected based on their individual affinity and selectivity. As a result, we obtained two mAbs that recognized the HSA Tyr 411 adduct of GD (mAb-5G2) or VX (mAb-12B9), respectively. They shared the highest affinity exhibiting a Kd value of about 10-6 mol/L of the OPNA exposure concentration. They also had remarkable selectivity, which could especially recognize their individual OPNA-HSA adducts in a native state but did not recognize other OPNA-HSAs and unadducted HSAs. Especially for mAb-12B9, it could clearly distinguish VX-HSA and GB-HSA between which there was only one alkyl difference in their phosphonyl portion of the adducted sites. The two mAbs were then used to build the icELISA method for analysis of the serum samples exposed to OPNA. It was found that the detectable lowest GD- and VX-exposed concentrations in serum samples were respectively 1.0 × 10-6 mol/L and 10.0 × 10-6 mol/L. This study provides one novel approach and strategy for the retrospective detection of OPNA exposure, and the two mAbs have great potential to be extended for point-of-care testing of OPNA intoxication.
Collapse
Affiliation(s)
- Qiao Lv
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing, 102205, China
| | - Hui-Lan Yu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing, 102205, China.
| | - Yang Yang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing, 102205, China
| | - Fan-Hua Meng
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Xian-Dong Dai
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Pei-Yu Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing, 102205, China
| | - Chang-Cai Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
- Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing, 102205, China.
| |
Collapse
|
7
|
Lee JH, Jang WE, Park JH, Mohammad HB, Lee J, Jeong W, Kim M. Identification of organophosphate modifications by high‐resolution mass spectrometry. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12478] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Wooyoung Eric Jang
- Department of Chemistry Kyung Hee University Gyeonggi‐do Republic of Korea
| | | | | | - Jin‐Young Lee
- Chem‐Bio Technology Center Agency for Defense Development Daejeon Republic of Korea
| | - Woo‐Hyeon Jeong
- Chem‐Bio Technology Center Agency for Defense Development Daejeon Republic of Korea
| | - Min‐Sik Kim
- New Biology DGIST Daegu Republic of Korea
- Department of Chemistry Kyung Hee University Gyeonggi‐do Republic of Korea
| |
Collapse
|
8
|
Abstract
Chemicals are measured regularly in air, food, the environment, and the workplace. Biomonitoring of chemicals in biological fluids is a tool to determine the individual exposure. Blood protein adducts of xenobiotics are a marker of both exposure and the biologically effective dose. Urinary metabolites and blood metabolites are short term exposure markers. Stable hemoglobin adducts are exposure markers of up to 120 days. Blood protein adducts are formed with many xenobiotics at different sites of the blood proteins. Newer methods apply the techniques developed in the field of proteomics. Larger adducted peptides with 20 amino acids are used for quantitation. Unfortunately, at present the methods do not reach the limits of detection obtained with the methods looking at single amino acid adducts or at chemically cleaved adducts. Therefore, to progress in the field new approaches are needed.
Collapse
|
9
|
Baygildiev TM, Braun AV, Vokuev MF, Stavrianidi AN, Rybalchenko IV, Rodin IA. Identification of Adducts of O-Isopropylmethylphosphonic and O-Cyclohexylmethylphosphonic Acids with a Tripeptide (Tyr-Thr-Lys) in Human Plasma by Liquid Chromatography–Mass Spectrometry. JOURNAL OF ANALYTICAL CHEMISTRY 2020. [DOI: 10.1134/s1061934820130031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
10
|
Wang H, Leeming MG, Cochran BJ, Hook JM, Ho J, Nguyen GTH, Zhong L, Supuran CT, Donald WA. Nontargeted Identification of Plasma Proteins O-, N-, and S-Transmethylated by O-Methyl Organophosphates. Anal Chem 2020; 92:15420-15428. [PMID: 33200920 DOI: 10.1021/acs.analchem.0c03077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Organophosphates (OPs) are used worldwide as pesticides. However, acute and chronic exposure to OPs can cause serious adverse health effects. The mechanism of delayed OP toxicity is thought to involve off-target inhibition of serine proteases, although the precise molecular details remain unclear owing to the lack of an analytical method for global detection of protein targets of OPs. Here, we report the development of a mass spectrometry method to identify OP-adducted proteins from complex mixtures in a nontargeted manner. Human plasma was incubated with the OP dichlorvos that was 50% isotopically labeled and 50% unlabeled. Proteins and protein adducts were extracted, digested, and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect "twin ions" of peptides that were covalently modified by a chemical reaction with dichlorvos. The LC-MS/MS data were processed by a blended data analytics software (Xenophile) to detect the amino acid residue sites of proteins that were covalently modified by exposure to OPs. We discovered that OPs can transmethylate the N, S, and O side chains of His, Cys, Glu, Asp, and Lys residues. For model systems, such transmethylation reactions were confirmed by LC-MS, nuclear magnetic resonance (NMR), and rationalized using electronic structure calculations. Methylation of the ubiquitous antioxidant glutathione by dichlorvos can decrease the reducing/oxidizing equilibrium of glutathione in liver extracts, which has been implicated in diseases and pathological conditions associated with delayed OP toxicity.
Collapse
Affiliation(s)
- Huixin Wang
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Michael G Leeming
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Blake J Cochran
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - James M Hook
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Junming Ho
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Giang T H Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Ling Zhong
- Mark Wainwright Analytical Centre, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Claudiu T Supuran
- Department of Neuroscience, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Sesto Fiorentino 50019, Italy
| | - William A Donald
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| |
Collapse
|
11
|
Stavrianidi AN, Braun AV, Stekolshchikova EA, Baygildiev TM, Rodin IA, Rybalchenko IV. Selection of Recording Conditions and Study of Fragmentation of a Peptide Biomarker of Sarin by High-Performance Liquid Chromatography–High-Resolution Mass Spectrometry. JOURNAL OF ANALYTICAL CHEMISTRY 2019. [DOI: 10.1134/s1061934818140137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
12
|
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]
|
13
|
Kranawetvogl A, Siegert M, Eyer F, Thiermann H, John H. Verification of organophosphorus pesticide poisoning: Detection of phosphorylated tyrosines and a cysteine-proline disulfide-adduct from human serum albumin after intoxication with dimethoate/omethoate. Toxicol Lett 2018; 299:11-20. [DOI: 10.1016/j.toxlet.2018.08.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/15/2018] [Accepted: 08/20/2018] [Indexed: 01/16/2023]
|
14
|
Ortega-Olvera JM, Winkler R, Quintanilla-Vega B, Shibayama M, Chávez-Munguía B, Martín-Tapia D, Alarcón L, González-Mariscal L. The organophosphate pesticide methamidophos opens the blood-testis barrier and covalently binds to ZO-2 in mice. Toxicol Appl Pharmacol 2018; 360:257-272. [PMID: 30291936 DOI: 10.1016/j.taap.2018.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 09/21/2018] [Accepted: 10/01/2018] [Indexed: 12/12/2022]
Abstract
Methamidophos (MET) is an organophosphate (OP) pesticide widely used in agriculture in developing countries. MET causes adverse effects in male reproductive function in humans and experimental animals, but the underlying mechanisms remain largely unknown. We explored the effect of MET on mice testes (5 mg/kg/day/4 days), finding that this pesticide opens the blood-testis barrier and perturbs spermatogenesis, generating the appearance of immature germ cells in the epididymis. In the seminiferous tubules, MET treatment changed the level of expression or modified the stage-specific localization of tight junction (TJ) proteins ZO-1, ZO-2, occludin, and claudin-3. In contrast, claudin-11 was barely altered. MET also modified the shape of claudin-11, and ZO-2 at the cell border, from a zigzag to a more linear pattern. In addition, MET diminished the expression of ZO-2 in spermatids present in seminiferous tubules, induced the phosphorylation of ZO-2 and occludin in testes and reduced the interaction between these proteins assessed by co-immunoprecipitation. MET formed covalent bonds with ZO-2 in serine, tyrosine and lysine residues. The covalent modifications formed on ZO-2 at putative phosphorylation sites might interfere with ZO-2 interaction with regulatory molecules and other TJ proteins. MET bonds formed at ZO-2 ubiquitination sites likely interfere with ZO-2 degradation and TJ sealing, based on results obtained in cultured epithelial cells transfected with ZO-2 mutated at a MET target lysine residue. Our results shed light on MET male reproductive toxicity and are important to improve regulations regarding the use of OP pesticides and to protect the health of agricultural workers.
Collapse
Affiliation(s)
| | - Robert Winkler
- Department of Biotechnology and Biochemistry, Cinvestav, Irapuato 36824, Mexico; Max Planck Institute for Chemical Ecology, Jena 07745, Germany
| | | | - Mineko Shibayama
- Department of Infectomics and Molecular Pathogenesis, Cinvestav, Mexico City 07360, Mexico
| | - Bibiana Chávez-Munguía
- Department of Infectomics and Molecular Pathogenesis, Cinvestav, Mexico City 07360, Mexico
| | - Dolores Martín-Tapia
- Department of Physiology, Biophysics and Neuroscience, Cinvestav, Mexico City 07360, Mexico
| | - Lourdes Alarcón
- Department of Physiology, Biophysics and Neuroscience, Cinvestav, Mexico City 07360, Mexico
| | | |
Collapse
|
15
|
Novel cysteine- and albumin-adduct biomarkers to prove human poisoning with the pesticide oxydemeton-S-methyl. Toxicol Lett 2018; 294:122-134. [DOI: 10.1016/j.toxlet.2018.05.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 12/21/2022]
|
16
|
A toolbox for microbore liquid chromatography tandem-high-resolution mass spectrometry analysis of albumin-adducts as novel biomarkers of organophosphorus pesticide poisoning. Toxicol Lett 2018; 292:46-54. [DOI: 10.1016/j.toxlet.2018.04.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/13/2018] [Accepted: 04/23/2018] [Indexed: 10/17/2022]
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Abdel-Daim A, Ohura K, Imai T. A novel quantification method for serine hydrolases in cellular expression system using fluorophosphonate-biotin probe. Eur J Pharm Sci 2018; 114:267-274. [DOI: 10.1016/j.ejps.2017.12.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/17/2017] [Accepted: 12/18/2017] [Indexed: 12/26/2022]
|
19
|
Onder S, Dafferner AJ, Schopfer LM, Xiao G, Yerramalla U, Tacal O, Blake TA, Johnson RC, Lockridge O. Monoclonal Antibody That Recognizes Diethoxyphosphotyrosine-Modified Proteins and Peptides Independent of Surrounding Amino Acids. Chem Res Toxicol 2017; 30:2218-2228. [PMID: 29137457 DOI: 10.1021/acs.chemrestox.7b00288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are irreversibly inhibited by organophosphorus pesticides through formation of a covalent bond with the active site serine. Proteins that have no active site serine, for example albumin, are covalently modified on tyrosine and lysine. Chronic illness from pesticide exposure is not explained by inhibition of AChE and BChE. Our goal was to produce a monoclonal antibody that recognizes proteins diethoxyphosphorylated on tyrosine. Diethoxyphosphate-tyrosine adducts for 13 peptides were synthesized. The diethoxyphosphorylated (OP) peptides cross-linked to four different carrier proteins were used to immunize, boost, and screen mice. Monoclonal antibodies were produced with hybridoma technology. Monoclonal antibody depY was purified and characterized by ELISA, western blotting, Biacore, and Octet technology to determine binding affinity and binding specificity. DepY recognized diethoxyphosphotyrosine independent of the amino acid sequence around the modified tyrosine and independent of the identity of the carrier protein or peptide. It had an IC50 of 3 × 10-9 M in a competition assay with OP tubulin. Kd values measured by Biacore and OctetRED96 were 10-8 M for OP-peptides and 1 × 10-12 M for OP-proteins. The limit of detection measured on western blots hybridized with 0.14 μg/mL of depY was 0.025 μg of human albumin conjugated to YGGFL-OP. DepY was specific for diethoxyphosphotyrosine (chlorpyrifos oxon adduct) as it failed to recognize diethoxyphospholysine, phosphoserine, phosphotyrosine, phosphothreonine, dimethoxyphosphotyrosine (dichlorvos adduct), dimethoxyphosphoserine, monomethoxyphosphotyrosine (aged dichlorvos adduct), and cresylphosphoserine. In conclusion, a monoclonal antibody that specifically recognizes diethoxyphosphotyrosine adducts has been developed. The depY monoclonal antibody could be useful for identifying new biomarkers of OP exposure.
Collapse
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
| | - 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
| | | | - 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, Chamblee, Georgia 30341, United States
| | - Rudolph C Johnson
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , 4770 Buford Highway NE, Chamblee, Georgia 30341, United States
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
| |
Collapse
|
20
|
Sun F, Ding J, Lu X, Gao R, Lu X, Shi E, Wang H, Pei C. Mass spectral characterization of tabun-labeled lysine biomarkers in albumin. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1057:54-61. [DOI: 10.1016/j.jchromb.2017.04.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/24/2017] [Accepted: 04/28/2017] [Indexed: 10/19/2022]
|
21
|
Sabbioni G, Turesky RJ. Biomonitoring Human Albumin Adducts: The Past, the Present, and the Future. Chem Res Toxicol 2017; 30:332-366. [PMID: 27989119 PMCID: PMC5241710 DOI: 10.1021/acs.chemrestox.6b00366] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Indexed: 12/21/2022]
Abstract
Serum albumin (Alb) is the most abundant protein in blood plasma. Alb reacts with many carcinogens and/or their electrophilic metabolites. Studies conducted over 20 years ago showed that Alb forms adducts with the human carcinogens aflatoxin B1 and benzene, which were successfully used as biomarkers in molecular epidemiology studies designed to address the role of these chemicals in cancer risk. Alb forms adducts with many therapeutic drugs or their reactive metabolites such as β-lactam antibiotics, acetylsalicylic acid, acetaminophen, nonsteroidal anti-inflammatory drugs, chemotherapeutic agents, and antiretroviral therapy drugs. The identification and characterization of the adduct structures formed with Alb have served to understand the generation of reactive metabolites and to predict idiosyncratic drug reactions and toxicities. The reaction of candidate drugs with Alb is now exploited as part of the battery of screening tools to assess the potential toxicities of drugs. The use of gas chromatography-mass spectrometry, liquid chromatography, or liquid chromatography-mass spectrometry (LC-MS) enabled the identification and quantification of multiple types of Alb xenobiotic adducts in animals and humans during the past three decades. In this perspective, we highlight the history of Alb as a target protein for adduction to environmental and dietary genotoxicants, pesticides, and herbicides, common classes of medicinal drugs, and endogenous electrophiles, and the emerging analytical mass spectrometry technologies to identify Alb-toxicant adducts in humans.
Collapse
Affiliation(s)
- Gabriele Sabbioni
- Institute of Environmental and Occupational Toxicology, CH-6780 Airolo, Switzerland
- Alpine Institute of Chemistry and Toxicology, CH-6718 Olivone, Switzerland
- Walther-Straub-Institut für Pharmakologie
und Toxikologie, Ludwig-Maximilians-Universität München, D-80336 München, Germany
| | - Robert J. Turesky
- Masonic Cancer Center and Department of
Medicinal Chemistry, College of Pharmacy, University of Minnesota, 2231 Sixth Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
22
|
Rehman T, Khan MM, Shad MA, Hussain M, Oyler BL, Goo YA, Goodlett DR. Detection of Carbofuran-Protein Adducts in Serum of Occupationally Exposed Pesticide Factory Workers in Pakistan. Chem Res Toxicol 2016; 29:1720-1728. [PMID: 27657490 DOI: 10.1021/acs.chemrestox.6b00222] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study was conducted to investigate the protein adducts with pesticides in a cohort of 172 factory workers that were exposed to a mixture of pesticides. The 35 samples showing considerable variation in biochemical parameters, i.e., butyrylcholinestrase (BChE), serum glutamic pyruvic transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT), gamma-glutamyl transferase (GGT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP/ALKP), lactate dehydrogenase (LDH), creatine phosphokinase (CPK) enzymes, and controls were analyzed by reversed-phase nanoscale liquid chromatography tandem mass spectrometry (nLC-MS/MS) on an Orbitrap mass spectrometer employing a shotgun proteomics approach. Only protein adducts with carbofuran were found on serum proteins of these workers. These adducts were of carbofuran labeled lysine (Lys-142, Lys-183, Lys-287, and Lys-467), arginine (Arg-210, Arg-242, and Arg-256) from serum albumin, and serine (Ser-07, Ser-54, and Ser-150) from immunoglobulin proteins. The arginine residues (Arg-210, Arg-242, Arg-246, and Arg-434) from albumin were also found to be glycated in serum of workers showing a high level of glucose who also had glycated arginine (Arg-1120) modified with carbofuran in their tankyrase-1-binding protein. The number of tandem mass spectra of modified peptides increased with increasing time of exposure. This is the first report to demonstrate the presence of carbofuran-labeled albumin, immunoglobulin, and glycated arginine, which shows that lysine and arginine of human albumin and serine of immunoglobulin are covalently modified in the serum of workers that were occupationally exposed to carbofuran, and the modification is detectable by tandem mass spectrometry. These peptides modified with carbofuran can potentially be used as a biomarker of carbofuran exposure.
Collapse
Affiliation(s)
- Tanzila Rehman
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| | - Mohd M Khan
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| | | | | | - Benjamin L Oyler
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| | - Young Ah Goo
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| | - David R Goodlett
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy , Baltimore, Maryland 21201, United States
| |
Collapse
|
23
|
Belabassi Y, Chao CK, Holly R, George KM, Nagy JO, Thompson CM. Preparation and characterization of diethoxy- and monoethoxy phosphylated ('aged') serine haptens and use in the production of monoclonal antibodies. Chem Biol Interact 2014; 223:134-40. [PMID: 25261769 DOI: 10.1016/j.cbi.2014.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/17/2014] [Accepted: 09/12/2014] [Indexed: 11/27/2022]
Abstract
In this study, the first mechanism-based monoclonal antibodies have been produced that recognize and differentiate diethoxy- and monoethoxyphosphorylated serine residues. Haptens were synthesized as the stable phosphonate form of phosphoserine esters to improve the immunoresponse. Following condensation with a glutaric anhydride to link the phosphoserine moieties to carrier protein, the hapten densities attached to bovine serum albumin and keyhole limpet henocyanin were determined by partial trypsin digestion and MALDI mass spectrometry, and confirmed using a fluorescent assay (FITC) to quantify unmodified lysine residues. The conjugation reactions were pH optimized to improve hapten density. Screening of subclones led to the identification of two monoclonal antibodies: (a) N257/25.11 that specifically recognizes (EtO)2P(O)-Ser as the phosphylated or inhibited form, and (b) N262/16 that recognizes (EtO)(HO)P(O)-Ser as the 'aged' form. Analysis of blood samples treated with paraoxon (EtO)2P(O)-OPhNO2 showed a concentration dependent recognition of the phosphylated form.
Collapse
Affiliation(s)
- Yamina Belabassi
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
| | - Chih-Kai Chao
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
| | - Ryan Holly
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
| | - Kathleen M George
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA
| | - Jon O Nagy
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
| | - Charles M Thompson
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA; Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA.
| |
Collapse
|
24
|
Crow BS, Pantazides BG, Quiñones-González J, Garton JW, Carter MD, Perez JW, Watson CM, Tomcik DJ, Crenshaw MD, Brewer BN, Riches JR, Stubbs SJ, Read RW, Evans RA, Thomas JD, Blake TA, Johnson RC. Simultaneous measurement of tabun, sarin, soman, cyclosarin, VR, VX, and VM adducts to tyrosine in blood products by isotope dilution UHPLC-MS/MS. Anal Chem 2014; 86:10397-405. [PMID: 25286390 DOI: 10.1021/ac502886c] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This work describes a new specific, sensitive, and rapid stable isotope dilution method for the simultaneous detection of the organophosphorus nerve agents (OPNAs) tabun (GA), sarin (GB), soman (GD), cyclosarin (GF), VR, VX, and VM adducts to tyrosine (Tyr). Serum, plasma, and lysed whole blood samples (50 μL) were prepared by protein precipitation followed by digestion with Pronase. Specific Tyr adducts were isolated from the digest by a single solid phase extraction (SPE) step, and the analytes were separated by reversed-phase ultra high performance liquid chromatography (UHPLC) gradient elution in less than 2 min. Detection was performed on a triple quadrupole tandem mass spectrometer using time-triggered selected reaction monitoring (SRM) in positive electrospray ionization (ESI) mode. The calibration range was characterized from 0.100-50.0 ng/mL for GB- and VR-Tyr and 0.250-50.0 ng/mL for GA-, GD-, GF-, and VX/VM-Tyr (R(2) ≥ 0.995). Inter- and intra-assay precision had coefficients of variation of ≤17 and ≤10%, respectively, and the measured concentration accuracies of spiked samples were within 15% of the targeted value for multiple spiking levels. The limit of detection was calculated to be 0.097, 0.027, 0.018, 0.074, 0.023, and 0.083 ng/mL for GA-, GB-, GD-, GF-, VR-, and VX/VM-Tyr, respectively. A convenience set of 96 serum samples with no known nerve agent exposure was screened and revealed no baseline values or potential interferences. This method provides a simple and highly specific diagnostic tool that may extend the time postevent that a confirmation of nerve agent exposure can be made with confidence.
Collapse
Affiliation(s)
- Brian S Crow
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention , Atlanta, Georgia 30341, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Bui-Nguyen TM, Dennis WE, Jackson DA, Stallings JD, Lewis JA. Detection of Dichlorvos Adducts in a Hepatocyte Cell Line. J Proteome Res 2014; 13:3583-95. [DOI: 10.1021/pr5000076] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Tri M. Bui-Nguyen
- Oak Ridge Institute
for Science and Education (ORISE) Postdoctoral Researcher, U.S. Army
Center for Environmental Health Research, 568 Doughten Drive, Fort Detrick, Maryland 21702, United States
| | - William E. Dennis
- U.S. Army Center for Environmental Health Research, 568 Doughten Drive, Fort
Detrick, Maryland 21702, United States
| | - David A. Jackson
- U.S. Army Center for Environmental Health Research, 568 Doughten Drive, Fort
Detrick, Maryland 21702, United States
| | - Jonathan D. Stallings
- U.S. Army Center for Environmental Health Research, 568 Doughten Drive, Fort
Detrick, Maryland 21702, United States
| | - John A. Lewis
- U.S. Army Center for Environmental Health Research, 568 Doughten Drive, Fort
Detrick, Maryland 21702, United States
| |
Collapse
|
26
|
V-type nerve agents phosphonylate ubiquitin at biologically relevant lysine residues and induce intramolecular cyclization by an isopeptide bond. Anal Bioanal Chem 2014; 406:5171-85. [DOI: 10.1007/s00216-014-7706-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 02/12/2014] [Accepted: 02/18/2014] [Indexed: 12/13/2022]
|
27
|
Jiang W, Dubrovskii YA, Podolskaya EP, Murashko EA, Babakov V, Nachon F, Masson P, Schopfer LM, Lockridge O. PHOS-select iron affinity beads enrich peptides for the detection of organophosphorus adducts on albumin. Chem Res Toxicol 2013; 26:1917-25. [PMID: 24187955 DOI: 10.1021/tx400352h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Albumin is covalently modified by organophosphorus toxicants (OP) on tyrosine 411, but less than 1% of albumin is modified in humans by lethal OP doses that inhibit 95% of plasma butyrylcholinesterase. A method that enriches OP-modified albumin peptides could aid analysis of low dose exposures. Soman or chlorpyrifos oxon treated human plasma was digested with pepsin. Albumin peptides were enriched by binding to Fe(3+) beads at pH 11 and eluted with pH 2.6 buffer. Similarly, mouse and guinea pig albumin modified by chlorpyrifos oxon were digested with pepsin and enriched by binding to Fe(3+) beads. Peptides were identified by MALDI-TOF/TOF mass spectrometry. PHOS-select iron affinity beads specifically enriched albumin peptides VRY411TKKVPQVST and LVRY411TKKVPQVST in a pepsin digest of human plasma. The unmodified as well as OP-modified peptides bound to the beads. The binding capacity of 500 μL of beads was the pepsin digest of 2.1 μL of human plasma. The limit of detection was 0.2% of OP-modified albumin peptide in 0.43 μL of plasma. Enrichment of OP-modified albumin peptides by binding to Fe(3+) beads is a method with potential application to diagnosis of OP pesticide and nerve agent exposure in humans, mice, and guinea pigs.
Collapse
Affiliation(s)
- Wei Jiang
- Eppley Institute, University of Nebraska Medical Center , Omaha, Nebraska 68198-5950, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Li B, Eyer P, Eddleston M, Jiang W, Schopfer LM, Lockridge O. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos. Toxicol Appl Pharmacol 2013; 269:215-25. [PMID: 23566956 DOI: 10.1016/j.taap.2013.03.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/26/2013] [Accepted: 03/27/2013] [Indexed: 10/27/2022]
Abstract
Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos.
Collapse
Affiliation(s)
- Bin Li
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 USA.
| | | | | | | | | | | |
Collapse
|
29
|
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]
|
30
|
|
31
|
Protein adducts as biomarkers of exposure to organophosphorus compounds. Toxicology 2012; 307:46-54. [PMID: 23261756 DOI: 10.1016/j.tox.2012.12.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 12/11/2012] [Accepted: 12/13/2012] [Indexed: 01/11/2023]
Abstract
Exposure to organophosphorus (OP) compounds can lead to serious neurological damage or death. Following bioactivation by the liver cytochromes P450, the OP metabolites produced are potent inhibitors of serine active-site enzymes including esterases, proteases and lipases. OPs may form adducts on other cellular proteins. Blood cholinesterases (ChEs) have long served as biomarkers of OP exposure in humans. However, the enzymatic assays used for biomonitoring OP exposures have several drawbacks. A more useful approach will focus on multiple biomarkers and avoid problems with the enzymatic activity assays. OP inhibitory effects result from a covalent bond with the active-site serine of the target enzymes. The serine OP adducts become irreversible following a process referred to as aging where one alkyl group dissociates over variable lengths of time depending on the OP adduct. The OP-adducted enzyme then remains in circulation until it is degraded, allowing for a longer window of detection compared with direct analysis of OPs or their metabolites. Mass spectrometry (MS) provides a very sensitive method for identification of post-translational protein modifications. MS analyses of the percentage adduction of the active-site serine of biomarker proteins such as ChEs will eliminate the need for basal activity levels of the individual and will provide for a more accurate determination of OP exposure. MS analysis of biomarker proteins also provides information about the OP that has caused inhibition. Other useful biomarker proteins include other serine hydrolases, albumin, tubulin and transferrin.
Collapse
|
32
|
Chen S, Zhang J, Lumley L, Cashman JR. Immunodetection of serum albumin adducts as biomarkers for organophosphorus exposure. J Pharmacol Exp Ther 2012. [PMID: 23192655 DOI: 10.1124/jpet.112.201368] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A major challenge in organophosphate (OP) research has been the identification and utilization of reliable biomarkers for the rapid, sensitive, and efficient detection of OP exposure. Although Tyr 411 OP adducts to human serum albumin (HSA) have been suggested to be one of the most robust biomarkers in the detection of OP exposure, the analysis of HSA-OP adduct detection has been limited to techniques using mass spectrometry. Herein, we describe the procurement of two monoclonal antibodies (mAb-HSA-GD and mAb-HSA-VX) that recognized the HSA Tyr 411 adduct of soman (GD) or S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), respectively, but did not recognize nonphosphonylated HSA. We showed that mAb-HSA-GD was able to detect the HSA Tyr 411 OP adduct at a low level (i.e., human blood plasma treated with 180 nM GD) that could not be detected by mass spectrometry. mAb-HSA-GD and mAb-HSA-VX showed an extremely low-level detection of GD adducted to HSA (on the order of picograms). mAb-HSA-GD could also detect serum albumin OP adducts in blood plasma samples from different animals administered GD, including rats, guinea pigs, and monkeys. The ability of the two antibodies to selectively recognize nerve agents adducted to serum albumin suggests that these antibodies could be used to identify biomarkers of OP exposure and provide a new biologic approach to detect OP exposure in animals.
Collapse
Affiliation(s)
- Sigeng Chen
- Human BioMolecular Research Institute, 5310 Eastgate Mall, San Diego, CA 92121, USA
| | | | | | | |
Collapse
|
33
|
Liyasova MS, Schopfer LM, Lockridge O. Cresyl saligenin phosphate, an organophosphorus toxicant, makes covalent adducts with histidine, lysine, and tyrosine residues of human serum albumin. Chem Res Toxicol 2012; 25:1752-61. [PMID: 22793878 DOI: 10.1021/tx300215g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
CBDP [2-(2-cresyl)-4H-1-3-2-benzodioxaphosphorin-2-oxide] is a toxic organophosphorus compound. It is generated in vivo from tri-ortho-cresyl phosphate (TOCP), a component of jet engine oil and hydraulic fluids. Exposure to TOCP was proven to occur on board aircraft by finding CBDP-derived phospho-butyrylcholinesterase in the blood of passengers. Adducts on BChE, however, do not explain the toxicity of CBDP. Critical target proteins of CBDP are yet to be identified. Our goal was to facilitate the search for the critical targets of CBDP by determining the range of amino acid residues capable of reacting with CBDP and characterizing the types of adducts formed. We used human albumin as a model protein. Mass spectral analysis of the tryptic digest of CBDP-treated human albumin revealed adducts on His-67, His-146, His-242, His-247, His-338, Tyr-138, Tyr-140, Lys-199, Lys-351, Lys-414, Lys-432, and Lys-525. Adducts formed on tyrosine residues were different from those formed on histidines and lysines. Tyrosines were organophosphorylated by CBDP, while histidine and lysine residues were alkylated. This is the first report of an organophosphorus compound with both phosphorylating and alkylating properties. The o-hydroxybenzyl adduct on histidine is novel. The ability of CBDP to form stable adducts on histidine, tyrosine, and lysine allows one to consider new mechanisms of toxicity from TOCP exposure.
Collapse
Affiliation(s)
- Mariya S Liyasova
- Department of Environmental, Agricultural & Occupational Health, University of Nebraska Medical Center, Omaha, NE 68198-5950, USA
| | | | | |
Collapse
|
34
|
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.
Collapse
Affiliation(s)
- Wei Jiang
- Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE 68198-5950, United States.
| | | | | |
Collapse
|
35
|
Schopfer LM, Lockridge O. Analytical approaches for monitoring exposure to organophosphorus and carbamate agents through analysis of protein adducts. Drug Test Anal 2012; 4:246-61. [DOI: 10.1002/dta.1325] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 09/29/2011] [Accepted: 10/02/2011] [Indexed: 12/16/2022]
Affiliation(s)
| | - Oksana Lockridge
- Eppley Institute; University of Nebraska Medical Center; Omaha; NE
| |
Collapse
|
36
|
Lockridge O, Schopfer LM. Review of tyrosine and lysine as new motifs for organophosphate binding to proteins that have no active site serine. Chem Biol Interact 2010; 187:344-8. [PMID: 20211158 PMCID: PMC2905678 DOI: 10.1016/j.cbi.2010.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 02/27/2010] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
Abstract
The accepted target for organophosphorus agent (OP) binding to enzymes is the active site serine in the consensus sequence Gly X Ser X Gly. New motifs have been identified by using mass spectrometry to fragment OP-labeled peptides. It has been found that OP can make covalent bonds with tyrosine and lysine in proteins that have no active site serine. The OP-tyrosine bond is stable, and does not undergo the decay seen with OP-serine. Information on OP binding to tyrosine has been applied to diagnosis of OP exposure, through the use of mass spectrometry to detect OP-labeled albumin in human and animal plasma. It is expected that the new OP binding motif will aid in the search for a mechanism of low dose OP toxicity. It is hypothesized that proteins involved in axonal transport, especially proteins whose function depends on reversible phosphorylation, are prime candidates for a role in OP-induced neurodegeneration. Treatment of neurodegenerative disorders could be developed by identifying methods to reverse OP binding to tyrosine.
Collapse
Affiliation(s)
- Oksana Lockridge
- Eppley Institute, 985950 University of Nebraska Medical Center, Omaha, NE 68198-5950, United States.
| | | |
Collapse
|
37
|
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for detection and identification of albumin phosphylation by organophosphorus pesticides and G- and V-type nerve agents. Anal Bioanal Chem 2010; 398:2677-91. [PMID: 20730528 DOI: 10.1007/s00216-010-4076-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/28/2010] [Accepted: 07/30/2010] [Indexed: 10/19/2022]
Abstract
Toxic organophosphorus compounds (OPC), e.g., pesticides and nerve agents (NA), are known to phosphylate distinct endogenous proteins in vivo and in vitro. OPC adducts of butyrylcholinesterase and albumin are considered to be valuable biomarkers for retrospective verification of OPC exposure. Therefore, we have detected and identified novel adducts of human serum albumin (HSA) by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Pure albumin and plasma were incubated with numerous pesticides and NA of the V- and G-type in different molar ratios. Samples were prepared either by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by in-gel enzymatic cleavage using endoproteinase Glu-C (Glu-C) or by combining highly albumin-selective affinity extraction with ultrafiltration followed by reduction, carbamidomethylation, and enzymatic cleavage (Glu-C) prior to MALDI-TOF MS analysis. Characteristic mass shifts for phosphylation revealed tyrosine adducts at Y(411) (Y(401)KFQNALLVRY(411)TKKVPQVSTPTLVE(425)), Y(148) and Y(150) (I(142)ARRHPY(148)FY(150)APE(153), single and double labeled), and Y(161) (L(154)LFFAKRY(161)KAAFTE(167)) produced by original NA (tabun, sarin, soman, cyclosarin, VX, Chinese VX, and Russian VX) as well as by chlorpyrifos-oxon, diisopropyl fluorophosphate (DFP), paraoxon-ethyl (POE), and profenofos. MALDI-MS/MS of the single-labeled I(142)-E(153) peptide demonstrated that Y(150) was phosphylated with preference to Y(148). Aged albumin adducts were not detected. The procedure described was reproducible and feasible for detection of adducts at the most reactive Y(411)-residue (S/N ≥ 3) when at least 1% of total albumin was labeled. This was achieved by incubating plasma with molar HSA/OPC ratios ranging from approximately 1:0.03 (all G-type NA, DFP, and POE) to 1:3 (V-type NA, profenofos). Relative signal intensity of the Y(411) adduct correlated well with the spotted relative molar amount underlining the usefulness for quantitative adduct determination. In conclusion, the current analytical design exhibits potential as a verification tool for high-dose exposure.
Collapse
|
38
|
Schopfer LM, Grigoryan H, Li B, Nachon F, Masson P, Lockridge O. Mass spectral characterization of organophosphate-labeled, tyrosine-containing peptides: characteristic mass fragments and a new binding motif for organophosphates. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:1297-311. [PMID: 19762289 PMCID: PMC2860652 DOI: 10.1016/j.jchromb.2009.07.026] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Revised: 07/11/2009] [Accepted: 07/17/2009] [Indexed: 10/20/2022]
Abstract
We have identified organophosphorus agent (OP)-tyrosine adducts on 12 different proteins labeled with six different OP. Labeling was achieved by treating pure proteins with up to 40-fold molar excess of OP at pH 8-8.6. OP-treated proteins were digested with trypsin, and peptides were separated by HPLC. Fragmentation patterns for 100 OP-peptides labeled on tyrosine were determined in the mass spectrometer. The goals of the present work were (1) to determine the common features of the OP-reactive tyrosines, and (2) to describe non-sequence MSMS fragments characteristic of OP-tyrosine peptides. Characteristic ions at 272 and 244 amu for tyrosine-OP immonium ions were nearly always present in the MSMS spectrum of peptides labeled on tyrosine by chlorpyrifos-oxon. Characteristic fragments also appeared from the parent ions that had been labeled with diisopropylfluorophosphate (216 amu), sarin (214 amu), soman (214 amu) or FP-biotin (227, 312, 329, 691 and 708 amu). In contrast to OP-reactive serines, which lie in the consensus sequence GXSXG, the OP-reactive tyrosines have no consensus sequence. Their common feature is the presence of nearby positively charged residues that activate the phenolic hydroxyl group. The significance of these findings is the recognition of a new binding motif for OP to proteins that have no active site serine. Modified peptides are difficult to find when the OP bears no radiolabel and no tag. The characteristic MSMS fragment ions are valuable because they are identifiers for OP-tyrosine, independent of the peptide.
Collapse
Affiliation(s)
| | - Hasmik Grigoryan
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, 68198
| | - Bin Li
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, 68198
| | - Florian Nachon
- Centre de Recherches du Service de Santé des Armées, Toxicology Dept, BP87, 38702 La Tronche Cedex, France
| | - Patrick Masson
- Centre de Recherches du Service de Santé des Armées, Toxicology Dept, BP87, 38702 La Tronche Cedex, France
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, 68198
| |
Collapse
|
39
|
Development of diagnostics in the search for an explanation of aerotoxic syndrome. Anal Biochem 2010; 404:64-74. [PMID: 20447373 DOI: 10.1016/j.ab.2010.04.032] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 04/09/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
Abstract
Aerotoxic syndrome is assumed to be caused by exposure to tricresyl phosphate, an additive in engine lubricants and hydraulic fluids that is activated to the toxic 2-(ortho-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (CBDP). Currently, there is no laboratory evidence to support intoxication of airline crew members by CBDP. Our goal was to develop methods for testing in vivo exposure by identifying and characterizing biomarkers. Mass spectrometry was used to study the reaction of CBDP with human albumin, free tyrosine, and human butyrylcholinesterase. Human albumin made a covalent bond with CBDP, adding a mass of 170amu to Tyr411 to yield the o-cresyl phosphotyrosine derivative. Human butyrylcholinesterase made a covalent bond with CBDP on Ser198 to yield five adducts with added masses of 80, 108, 156, 170, and 186amu. The most abundant adduct had an added mass of 80amu from phosphate (HPO(3)), a surprising result given that no pesticide or nerve agent is known to yield phosphorylated serine with an added mass of 80amu. The next most abundant adduct had an added mass of 170amu to form o-cresyl phosphoserine. It is concluded that toxic gases or oil mists in cabin air may form adducts on plasma butyrylcholinesterase and albumin, detectable by mass spectrometry.
Collapse
|
40
|
Black RM. History and perspectives of bioanalytical methods for chemical warfare agent detection. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:1207-15. [DOI: 10.1016/j.jchromb.2009.11.025] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 11/10/2009] [Accepted: 11/12/2009] [Indexed: 02/02/2023]
|
41
|
Li B, Ricordel I, Schopfer LM, Baud F, Mégarbane B, Nachon F, Masson P, Lockridge O. Detection of adduct on tyrosine 411 of albumin in humans poisoned by dichlorvos. Toxicol Sci 2010; 116:23-31. [PMID: 20395308 DOI: 10.1093/toxsci/kfq117] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Studies in mice and guinea pigs have shown that albumin is a new biomarker of organophosphorus toxicant (OP) and nerve agent exposure. Our goal was to determine whether OP-labeled albumin could be detected in the blood of humans exposed to OP. Blood from four OP-exposed patients was prepared for mass spectrometry analysis by digesting 0.010 ml of serum with pepsin and purifying the labeled albumin peptide by offline high performance liquid chromatography. Dimethoxyphosphate-labeled tyrosine 411 was identified in albumin peptides VRY(411)TKKVPQVSTPTL and LVRY(411)TKKVPQVSTPTL from two patients who had attempted suicide with dichlorvos. The butyrylcholinesterase activity in these serum samples was inhibited 80%. A third patient whose serum BChE activity was inhibited 8% by accidental inhalation of dichlorvos had undetectable levels of adduct on albumin. A fourth patient whose BChE activity was inhibited 60% by exposure to chlorpyrifos had no detectable adduct on albumin. This is the first report to demonstrate the presence of OP-labeled albumin in human patients. It is concluded that tyrosine 411 of human albumin is covalently modified in the serum of humans poisoned by dichlorvos and that the modification is detectable by mass spectrometry. The special reactivity of tyrosine 411 with OP suggests that other proteins may also be modified on tyrosine. Identification of other OP-modified proteins may lead to an understanding of neurotoxic symptoms that appear long after the initial OP exposure.
Collapse
Affiliation(s)
- Bin Li
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Drastic decrease in dopamine receptor levels in the striatum of acetylcholinesterase knock-out mouse. Chem Biol Interact 2010; 183:194-201. [PMID: 19818744 DOI: 10.1016/j.cbi.2009.09.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 09/29/2009] [Accepted: 09/30/2009] [Indexed: 11/22/2022]
Abstract
BACKGROUND The acetylcholinesterase knock-out mouse lives to adulthood despite 60-fold elevated acetylcholine concentrations in the brain that are lethal to wild-type animals. Part of its mechanism of survival is a 50% decrease in muscarinic and nicotinic receptors and a 50% decrease in adrenoceptor levels. HYPOTHESIS The hypothesis was tested that the dopaminergic neuronal system had also adapted. METHODS Radioligand binding assays measured dopamine receptor level and binding affinity in the striatum. Immunohistochemistry of brain sections with specific antibodies visualized dopamine transporter. Effects on the intracellular compartment were measured as cAMP content, PI-phospholipase C activity. RESULTS Dopamine receptor levels were decreased 28-fold for the D(1)-like, and more than 37-fold for the D(2)-like receptors, though binding affinity was normal. Despite these huge changes in receptor levels, dopamine transporter levels were not affected. The intracellular compartment had normal levels of cAMP and PI-phospholipase C activity. CONCLUSION Survival of the acetylcholinesterase knock-out mouse could be linked to adaptation of many neuronal systems during development including the cholinergic, adrenergic and dopaminergic. These adaptations balance the overstimulation of cholinergic receptors caused by high acetylcholine concentrations and thus maintain homeostasis inside the cell, allowing the animal to live.
Collapse
|
43
|
Thompson CM, Prins JM, George KM. Mass spectrometric analyses of organophosphate insecticide oxon protein adducts. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:11-9. [PMID: 20056576 PMCID: PMC2831953 DOI: 10.1289/ehp.0900824] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2009] [Accepted: 07/29/2009] [Indexed: 05/03/2023]
Abstract
OBJECTIVE Organophosphate (OP) insecticides continue to be used to control insect pests. Acute and chronic exposures to OP insecticides have been documented to cause adverse health effects, but few OP-adducted proteins have been correlated with these illnesses at the molecular level. Our aim was to review the literature covering the current state of the art in mass spectrometry (MS) used to identify OP protein biomarkers. DATA SOURCES AND EXTRACTION We identified general and specific research reports related to OP insecticides, OP toxicity, OP structure, and protein MS by searching PubMed and Chemical Abstracts for articles published before December 2008. DATA SYNTHESIS A number of OP-based insecticides share common structural elements that result in predictable OP-protein adducts. The resultant OP-protein adducts show an increase in molecular mass that can be identified by MS and correlated with the OP agent. Customized OP-containing probes have also been used to tag and identify protein targets that can be identified by MS. CONCLUSIONS MS is a useful and emerging tool for the identification of proteins that are modified by activated organophosphate insecticides. MS can characterize the structure of the OP adduct and also the specific amino acid residue that forms the key bond with the OP. Each protein that is modified in a unique way by an OP represents a unique molecular biomarker that with further research can lead to new correlations with exposure.
Collapse
Affiliation(s)
- Charles M Thompson
- Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana 59812, USA.
| | | | | |
Collapse
|
44
|
Biomarkers of organophosphorus nerve agent exposure: comparison of phosphylated butyrylcholinesterase and phosphylated albumin after oxime therapy. Arch Toxicol 2009; 84:25-36. [DOI: 10.1007/s00204-009-0473-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 09/17/2009] [Indexed: 12/13/2022]
|
45
|
Mass spectrometry identifies multiple organophosphorylated sites on tubulin. Toxicol Appl Pharmacol 2009; 240:149-58. [PMID: 19632257 DOI: 10.1016/j.taap.2009.07.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 07/17/2009] [Accepted: 07/17/2009] [Indexed: 11/20/2022]
Abstract
Acute toxicity of organophosphorus poisons (OP) is explained by inhibition of acetylcholinesterase in nerve synapses. Low-dose effects are hypothesized to result from modification of other proteins, whose identity is not yet established. The goal of the present work was to obtain information that would make it possible to identify tubulin as a target of OP exposure. Tubulin was selected for study because live mice injected with a nontoxic dose of a biotinylated organophosphorus agent appeared to have OP-labeled tubulin in brain as determined by binding to avidin beads and mass spectrometry. The experiments with live mice were not conclusive because binding to avidin beads could be nonspecific. To be convincing, it is necessary to find and characterize the OP-labeled tubulin peptide. The search for OP-labeled tubulin peptides was begun by identifying residues capable of making a covalent bond with OP. Pure bovine tubulin (0.012 mM) was treated with 0.01-0.5 mM chlorpyrifos oxon for 24 h at 37 degrees C in pH 8.3 buffer. The identity of labeled amino acids and percent labeling was determined by mass spectrometry. Chlorpyrifos oxon bound covalently to tyrosines 83, 103, 108, 161, 224, 262, 272, 357, and 399 in bovine alpha tubulin, and to tyrosines 50, 51, 59, 106, 159, 281, 310, and 340 in bovine beta tubulin. The most reactive were tyrosine 83 in alpha and tyrosine 281 in beta tubulin. In the presence of 1 mM GTP, percent labeling increased 2-fold. Based on the crystal structure of the tubulin heterodimer (PDB 1jff) tyrosines 83 and 281 are well exposed to solvent. In conclusion seventeen tyrosines in tubulin have the potential to covalently bind chlorpyrifos oxon. These results will be useful when searching for OP-labeled tubulin in live animals.
Collapse
|
46
|
Grigoryan H, Li B, Xue W, Grigoryan M, Schopfer LM, Lockridge O. Mass spectral characterization of organophosphate-labeled lysine in peptides. Anal Biochem 2009; 394:92-100. [PMID: 19596251 DOI: 10.1016/j.ab.2009.07.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 07/01/2009] [Accepted: 07/02/2009] [Indexed: 12/13/2022]
Abstract
Organophosphate (OP) esters bind covalently to the active site serine of enzymes in the serine hydrolase family. Recently, mass spectrometry identified covalent binding of OPs to tyrosine in a wide variety of proteins when purified proteins were incubated with OPs. In the current work, manual inspection of tandem mass spectrometry (MS/MS) data led to the realization that lysines also make a covalent bond with OPs. OP-labeled lysine residues were found in seven proteins that had been treated with either chlorpyrifos oxon (CPO) or diisopropylfluorophosphate (DFP): human serum albumin (K212, K414, K199, and K351), human keratin 1 (K211 and K355), human keratin 10 (K163), bovine tubulin alpha (K60, K336, K163, K394, and K401), bovine tubulin beta (K58), bovine actin (K113, K291, K326, K315, and K328), and mouse transferrin (K296 and K626). These results suggest that OP binding to lysine is a general phenomenon. Characteristic fragments specific for CPO-labeled lysine appeared at 237.1, 220.0, 192.0, 163.9, 128.9, and 83.9amu. Characteristic fragments specific for DFP-labeled lysine appeared at 164.0, 181.2, and 83.8amu. This new OP-binding motif to lysine suggests new directions to search for mechanisms of long-term effects of OP exposure and in the search for biomarkers of OP exposure.
Collapse
Affiliation(s)
- Hasmik Grigoryan
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | | | | | | | | | | |
Collapse
|
47
|
Grigoryan H, Li B, Anderson EK, Xue W, Nachon F, Lockridge O, Schopfer LM. Covalent binding of the organophosphorus agent FP-biotin to tyrosine in eight proteins that have no active site serine. Chem Biol Interact 2009; 180:492-8. [PMID: 19539807 DOI: 10.1016/j.cbi.2009.03.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 03/23/2009] [Accepted: 03/24/2009] [Indexed: 11/25/2022]
Abstract
Organophosphorus (OP) esters are known to bind covalently to the active site serine of enzymes in the serine hydrolase family. It was a surprise to find that proteins with no active site serine are also covalently modified by OP. The binding site in albumin, transferrin, and tubulin was identified as tyrosine. The goal of the present work was to determine whether binding to tyrosine is a general phenomenon. Fourteen proteins were treated with a biotin-tagged organophosphorus agent called FP-biotin. The proteins were digested with trypsin and the labeled peptides enriched by binding to monomeric avidin. Peptides were purified by HPLC and fragmented by collision induced dissociation in a tandem ion trap mass spectrometer. Eight proteins were labeled and six were not. Tyrosine was labeled in human alpha-2-glycoprotein 1 zinc-binding protein (Tyr 138, Tyr 174 and Tyr 181), human kinesin 3C motor domain (Tyr 145), human keratin 1 (Tyr 230), bovine actin (Tyr 55 and Tyr 200), murine ATP synthase beta (Tyr 431), murine adenine nucleotide translocase 1 (Tyr 81), bovine chymotrypsinogen (Tyr 201) and porcine pepsin (Tyr 310). Only 1-3 tyrosines per protein were modified, suggesting that the reactive tyrosine was activated by nearby residues that facilitated ionization of the hydroxyl group of tyrosine. These results suggest that OP binding to tyrosine is a general phenomenon. It is concluded that organophosphorus-reactive proteins include not only enzymes in the serine hydrolase family, but also proteins that have no active site serine. The recognition of a new OP-binding motif to tyrosine suggests new directions to search for mechanisms of long-term effects of OP exposure. Another application is in the search for biomarkers of organophosphorus agent exposure. Previous searches have been limited to serine hydrolases. Now proteins such as albumin and keratin can be considered.
Collapse
Affiliation(s)
- Hasmik Grigoryan
- Eppley Institute, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, United States.
| | | | | | | | | | | | | |
Collapse
|
48
|
Masson P, Rochu D. Catalytic bioscavengers against toxic esters, an alternative approach for prophylaxis and treatments of poisonings. Acta Naturae 2009; 1:68-79. [PMID: 22649587 PMCID: PMC3347506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Bioscavengers are biopharmaceuticals that specifically react with toxicants. Thus, enzymes reacting with poisonous esters can be used as bioscavengers for neutralization of toxic molecules before they reach physiological targets. Parenteral administration of bioscavengers is, therefore, intended for prophylaxis or pre-treatments, emergency and post-exposure treatments of intoxications. These enzymes can also be used for application on skin, mucosa and wounds as active components of topical skin protectants and decontamination solutions. Human butyrylcholinesterase is the first stoichiometric bioscavenger for safe and efficient prophylaxis of organophosphate poisoning. However, huge amounts of a costly enzyme are needed for protection. Thus, the bioscavenger approach will be greatly improved by the use of catalytic bioscavengers. Catalytic bioscavengers are enzymes capable of degrading toxic esters with a turnover. Suitable catalytic bioscavengers are engineered mutants of human enzymes. Efficient mutants of human butyrylcholinesterase have been made that hydrolyze cocaine at a high rate. Mutants of human cholinesterases capable of hydrolyzing OPs have been made, but so far their activity is too low to be of medical interest. Human paraoxonase a promiscuous plasma enzyme is certainly the most promising phosphotriesterase. However, its biotechnology is still in its infancy. Other enzymes and proteins from blood and organs, and secondary biological targets of OPs and carbamates are potential bioscavengers, in particular serum albumin that reacts with OPs and self-reactivates. Lastly, non-human enzymes, phosphotriesterases and oxidases from various bacterial and eukaryotic sources could be used for external use against OP poisoning and for internal use after modifications for immunological compatibility.
Collapse
Affiliation(s)
- Patrick Masson
- Centre de Recherches du Service de Santé des Armées, Toxicology department, La Tronche, France
| | | |
Collapse
|
49
|
Li B, Schopfer LM, Grigoryan H, Thompson CM, Hinrichs SH, Masson P, Lockridge O. Tyrosines of human and mouse transferrin covalently labeled by organophosphorus agents: a new motif for binding to proteins that have no active site serine. Toxicol Sci 2008; 107:144-55. [PMID: 18930948 DOI: 10.1093/toxsci/kfn211] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The expectation from the literature is that organophosphorus (OP) agents bind to proteins that have an active site serine. However, transferrin, a protein with no active site serine, was covalently modified in vitro by 0.5mM 10-fluoroethoxyphosphinyl-N-biotinamido pentyldecanamide, chlorpyrifos oxon, diisopropylfluorophosphate, dichlorvos, sarin, and soman. The site of covalent attachment was identified by analyzing tryptic peptides in the mass spectrometer. Tyr 238 and Tyr 574 in human transferrin and Tyr 238, Tyr 319, Tyr 429, Tyr 491, and Tyr 518 in mouse transferrin were labeled by OP. Tyrosine in the small synthetic peptide ArgTyrThrArg made a covalent bond with diisopropylfluorophosphate, chlorpyrifos oxon, and dichlorvos at pH 8.3. These results, together with our previous demonstration that albumin and tubulin bind OP on tyrosine, lead to the conclusion that OP bind covalently to tyrosine, and that OP binding to tyrosine is a new OP-binding residue. The OP-reactive tyrosines are activated by interaction with Arg or Lys. It is suggested that many proteins in addition to those already identified may be modified by OP on tyrosine. The extent to which tyrosine modification by OP can occur in vivo and the toxicological implications of such modifications require further investigation.
Collapse
Affiliation(s)
- Bin Li
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
| | | | | | | | | | | | | |
Collapse
|