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Šinko G. Modeling of a near-attack conformation of oxime in phosphorylated acetylcholinesterase via a reactivation product, a phosphorylated oxime. Chem Biol Interact 2023; 383:110656. [PMID: 37579936 DOI: 10.1016/j.cbi.2023.110656] [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: 02/09/2023] [Revised: 07/26/2023] [Accepted: 08/09/2023] [Indexed: 08/16/2023]
Abstract
At the present, only four antidotes are in use in therapy for poisoning by organophosphorus compounds: 2-PAM, HI-6, obidoxime and trimedoxime. Numerous compounds have been designed and synthetized to be more effective reactivators than those currently in use. Many of those new compounds fail at the enzyme level because interactions formed within the AChE active site are not favourable ones that lead to a successful reactivation. The approach in which the modeling of a phosphorylated oxime (POX), a product of successful reactivation in the AChE active site, may be a way to better understand the role of active site residues during the process of formation of the Michaelis type of complex between an enzyme and oxime. After reactivation, a change in phosphorus stereochemistry occurs leading to a different spatial arrangement of attached substituents, now including an oxime. To study interactions between the AChE oxyanion hole and a phosphorylated oxime, an S203G mutant was used to avoid the steric hindrance caused by the catalytic serine. In this way, the POX could be positioned close to the oxyanion hole. In the final step, the oxime without a phosphoester moiety was transferred into the phosphorylated AChE and molecular dynamics was used to test the stability of the near-attack conformation of the oxime near the phosphorylated serine.
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Affiliation(s)
- Goran Šinko
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10 000, Zagreb, Croatia.
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2
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Cruz-Castillo AU, Rodríguez-Valdez LM, Correa-Basurto J, Nogueda-Torres B, Andrade-Ochoa S, Nevárez-Moorillón GV. Terpenic Constituents of Essential Oils with Larvicidal Activity against Aedes Aegypti: A QSAR and Docking Molecular Study. Molecules 2023; 28:molecules28062454. [PMID: 36985426 PMCID: PMC10054420 DOI: 10.3390/molecules28062454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/30/2023] Open
Abstract
Aedes aegypti is a vector for the arbovirus responsible for yellow fever, Zika and Chikungunya virus. Essential oils and their constituents are known for their larvicidal properties and are strong candidates for mosquito control. This work aimed to develop a quantitative structure-activity study and molecular screening for the search and design of new larvicidal agents. Twenty-five monoterpenes with previously evaluated larvicidal activity were built and optimized using computational tools. QSAR models were constructed through genetic algorithms from the larvicidal activity and the calculation of theoretical descriptors for each molecule. Docking studies on acetylcholinesterase (AChE) and sterol carrier protein (SCP-2) were also carried out. Results demonstrate that the epoxide groups in the structure of terpenes hinder larvicidal activity, while lipophilicity plays an important role in enhancing biological activity. Larvicidal activity correlates with the interaction of the sterol-carrier protein. Of the 25 compounds evaluated, carvacrol showed the highest larvicidal activity with an LC50 of 8.8 µg/mL. The information included in this work contributes to describing the molecular, topological, and quantum mechanical properties related to the larvicidal activity of monoterpenes and their derivatives.
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Affiliation(s)
- Adrián Ulises Cruz-Castillo
- Campus Coyoacán, Universidad del Valle de México, Calzada De Tlalpan No. 3016 y 3058, Ex Hacienda Coapa, Delegación Coyoacán, Ciudad de México 04910, Mexico
| | - Luz María Rodríguez-Valdez
- Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Circuito Universitario S/N Campus Universitario II, Chihuahua 31125, Mexico
| | - José Correa-Basurto
- Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón S/N Col. Santo Tomas, Ciudad de México 11340, Mexico
| | - Benjamín Nogueda-Torres
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N Col. Santo Tomas, Ciudad de México 11340, Mexico
| | - Sergio Andrade-Ochoa
- Campus Coyoacán, Universidad del Valle de México, Calzada De Tlalpan No. 3016 y 3058, Ex Hacienda Coapa, Delegación Coyoacán, Ciudad de México 04910, Mexico
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3
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Ould Lamara K, Makhloufi-Chebli M, Benazzouz-Touami A, Terrachet-Bouaziz S, Robert A, Machado-Rodrigues C, Behr JB. Synthesis, biological activities of chalcones and novel 4-acetylpyridine oximes, molecular docking of the synthesized products as acetylcholinesterase ligands. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.132153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Assessment of four organophosphorus pesticides as inhibitors of human acetylcholinesterase and butyrylcholinesterase. Sci Rep 2021; 11:21486. [PMID: 34728713 PMCID: PMC8563940 DOI: 10.1038/s41598-021-00953-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/20/2021] [Indexed: 11/08/2022] Open
Abstract
Toxicity of organophosphorus compounds (OPs) remains a major public health concern due to their widespread use as pesticides and the existence of nerve agents. Their common mechanism of action involves inhibition of enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are crucial for neurotransmission. Both chronic and acute poisoning by OPs can leave long-lasting health effects even when the patients are treated with standard medical therapy. Therefore, an increasing urgency exists to find more effective oxime reactivators for compounds which are resistant to reactivation, especially phosphoramidates. Here, we investigated in silico and in vitro interactions and kinetics of inhibition for human cholinesterases with four organophosphate pesticides-ethoprophos, fenamiphos, methamidophos and phosalone. Overall, ethoprophos and fenamiphos displayed higher potency as inhibitors for tested cholinesterases. Our results show that methamidophos-inhibited hAChE was more susceptible to reactivation than hAChE inhibited by fenamiphos by selected oximes. Molecular modelling enabled an evaluation of interactions important for specificity and selectivity of both inhibition and reactivation of cholinesterases. Two newly developed reactivators-bispyridinium triazole oxime 14A and zwitterionic oxime RS194B possess remarkable potential for further development of antidotes directed against pesticides and related phosphoramidate exposures, such as nerve agents tabun or Novichoks.
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Almeida JR, Palmeira A, Campos A, Cunha I, Freitas M, Felpeto AB, Turkina MV, Vasconcelos V, Pinto M, Correia-da-Silva M, Sousa E. Structure-Antifouling Activity Relationship and Molecular Targets of Bio-Inspired(thio)xanthones. Biomolecules 2020; 10:biom10081126. [PMID: 32751491 PMCID: PMC7463931 DOI: 10.3390/biom10081126] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/23/2020] [Accepted: 07/27/2020] [Indexed: 12/28/2022] Open
Abstract
The development of alternative ecological and effective antifouling technologies is still challenging. Synthesis of nature-inspired compounds has been exploited, given the potential to assure commercial supplies of potential ecofriendly antifouling agents. In this direction, the antifouling activity of a series of nineteen synthetic small molecules, with chemical similarities with natural products, were exploited in this work. Six (4, 5, 7, 10, 15 and 17) of the tested xanthones showed in vivo activity toward the settlement of Mytilus galloprovincialis larvae (EC50: 3.53–28.60 µM) and low toxicity to this macrofouling species (LC50 > 500 µM and LC50/EC50: 17.42–141.64), and two of them (7 and 10) showed no general marine ecotoxicity (<10% of Artemia salina mortality) after 48 h of exposure. Regarding the mechanism of action in mussel larvae, the best performance compounds 4 and 5 might be acting by the inhibition of acetylcholinesterase activity (in vitro and in silico studies), while 7 and 10 showed specific targets (proteomic studies) directly related with the mussel adhesive structure (byssal threads), given by the alterations in the expression of Mytilus collagen proteins (PreCols) and proximal thread proteins (TMPs). A quantitative structure-activity relationship (QSAR) model was built with predictive capacity to enable speeding the design of new potential active compounds.
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Affiliation(s)
- Joana R. Almeida
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
| | - Andreia Palmeira
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Alexandre Campos
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
| | - Isabel Cunha
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
| | - Micaela Freitas
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, P 4069-007 Porto, Portugal
- ISPSO—Institut des Sciences Pharmaceutiques de Suisse Occidentale, University of Geneva, 1205 Geneva, Switzerland
| | - Aldo Barreiro Felpeto
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
| | - Maria V. Turkina
- Department of Biomedical and Clinical Sciences, Linköping University, SE-581 85 Linköping, Sweden;
| | - Vitor Vasconcelos
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, P 4069-007 Porto, Portugal
| | - Madalena Pinto
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Marta Correia-da-Silva
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
- Correspondence:
| | - Emília Sousa
- CIIMAR/CIMAR—Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, 4450-208 Matosinhos, Portugal; (J.R.A.); (A.P.); (A.C.); (I.C.); (M.F.); (A.B.F.); (V.V.); (M.P.); (E.S.)
- Laboratory of Organic and Pharmaceutical Chemistry, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
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6
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Lushchekina SV, Masson P. Slow-binding inhibitors of acetylcholinesterase of medical interest. Neuropharmacology 2020; 177:108236. [PMID: 32712274 DOI: 10.1016/j.neuropharm.2020.108236] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/11/2020] [Accepted: 07/10/2020] [Indexed: 12/15/2022]
Abstract
Certain ligands slowly bind to acetylcholinesterase. As a result, there is a slow establishment of enzyme-inhibitor equilibrium characterized by a slow onset of inhibition prior reaching steady state. Three mechanisms account for slow-binding inhibition: a) slow binding rate constant kon, b) slow ligand induced-fit following a fast binding step, c) slow conformational selection of an enzyme form. The slow equilibrium may be followed by a chemical step. This later that can be irreversible has been observed with certain alkylating agents and substrate transition state analogs. Slow-binding inhibitors present long residence times on target. This results in prolonged pharmacological or toxicological action. Through several well-known molecules (e.g. huperzine) and new examples (tocopherol, trifluoroacetophenone and a 6-methyluracil alkylammonium derivative), we show that slow-binding inhibitors of acetylcholinesterase are promising drugs for treatment of neurological diseases such as Alzheimer disease and myasthenia gravis. Moreover, they may be of interest for neuroprotection (prophylaxis) against organophosphorus poisoning. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Sofya V Lushchekina
- Laboratory of Computer Modeling of Biomolecular Systems and Nanomaterials, Emanuel Institute of Biochemical Physics of RAS, 4 Kosygina St., Moscow, 119334, Russia.
| | - Patrick Masson
- Laboratory of Neuropharmacology, Kazan Federal University, 18 Kremlyovskaya St., Kazan, 420008, Russia.
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Bester SM, Guelta MA, Cheung J, Winemiller MD, Bae SY, Myslinski J, Pegan SD, Height JJ. Structural Insights of Stereospecific Inhibition of Human Acetylcholinesterase by VX and Subsequent Reactivation by HI-6. Chem Res Toxicol 2018; 31:1405-1417. [PMID: 30462502 DOI: 10.1021/acs.chemrestox.8b00294] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Over 50 years ago, the toxicity of irreversible organophosphate inhibitors targeting human acetylcholinesterase (hAChE) was observed to be stereospecific. The therapeutic reversal of hAChE inhibition by reactivators has also been shown to depend on the stereochemistry of the inhibitor. To gain clarity on the mechanism of stereospecific inhibition, the X-ray crystallographic structures of hAChE inhibited by a racemic mixture of VX (P R/S) and its enantiomers were obtained. Beyond identifying hAChE structural features that lend themselves to stereospecific inhibition, structures of the reactivator HI-6 bound to hAChE inhibited by VX enantiomers of varying toxicity, or in its uninhibited state, were obtained. Comparison of hAChE in these pre-reactivation and post-reactivation states along with enzymatic data reveals the potential influence of unproductive reactivator poses on the efficacy of these types of therapeutics. The recognition of structural features related to hAChE's stereospecificity toward VX shed light on the molecular influences of toxicity and their effect on reactivators. In addition to providing a better understanding of the innate issues with current reactivators, an avenue for improvement of reactivators is envisioned.
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Affiliation(s)
- Stephanie M Bester
- Department of Pharmaceutical and Biomedical Sciences , University of Georgia , Athens , Georgia 30602 , United States
| | - Mark A Guelta
- Edgewood Chemical Biological Center, United States Army , Aberdeen Proving Ground, Aberdeen , Maryland 21010 , United States
| | - Jonah Cheung
- New York Structural Biology Center , New York , New York 10027 , United States
| | - Mark D Winemiller
- Edgewood Chemical Biological Center, United States Army , Aberdeen Proving Ground, Aberdeen , Maryland 21010 , United States
| | - Su Y Bae
- Edgewood Chemical Biological Center, United States Army , Aberdeen Proving Ground, Aberdeen , Maryland 21010 , United States
| | - James Myslinski
- Edgewood Chemical Biological Center, United States Army , Aberdeen Proving Ground, Aberdeen , Maryland 21010 , United States
| | - Scott D Pegan
- Department of Pharmaceutical and Biomedical Sciences , University of Georgia , Athens , Georgia 30602 , United States.,Edgewood Chemical Biological Center, United States Army , Aberdeen Proving Ground, Aberdeen , Maryland 21010 , United States
| | - Jude J Height
- Edgewood Chemical Biological Center, United States Army , Aberdeen Proving Ground, Aberdeen , Maryland 21010 , United States
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8
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Oxime-assisted reactivation of tabun-inhibited acetylcholinesterase analysed by active site mutations. Toxicology 2018; 406-407:104-113. [DOI: 10.1016/j.tox.2018.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 05/08/2018] [Accepted: 05/13/2018] [Indexed: 11/18/2022]
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9
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Bikshapathi R, Sai Prathima P, Yashwanth B, Rajesh P, Rao JV, Jagadeesh Kumar G, Jagadeesh N, Rao VJ. An expeditious protocol for synthesis of Baylis–Hillman derived piperazine derivatives and evaluation of their AChE inhibition. RESEARCH ON CHEMICAL INTERMEDIATES 2017. [DOI: 10.1007/s11164-017-3119-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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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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11
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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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12
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Franklin MC, Rudolph MJ, Ginter C, Cassidy MS, Cheung J. Structures of paraoxon-inhibited human acetylcholinesterase reveal perturbations of the acyl loop and the dimer interface. Proteins 2016; 84:1246-56. [PMID: 27191504 DOI: 10.1002/prot.25073] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/18/2016] [Accepted: 05/08/2016] [Indexed: 11/06/2022]
Abstract
Irreversible inhibition of the essential nervous system enzyme acetylcholinesterase by organophosphate nerve agents and pesticides may quickly lead to death. Oxime reactivators currently used as antidotes are generally less effective against pesticide exposure than nerve agent exposure, and pesticide exposure constitutes the majority of cases of organophosphate poisoning in the world. The current lack of published structural data specific to human acetylcholinesterase organophosphate-inhibited and oxime-bound states hinders development of effective medical treatments. We have solved structures of human acetylcholinesterase in different states in complex with the organophosphate insecticide, paraoxon, and oximes. Reaction with paraoxon results in a highly perturbed acyl loop that causes a narrowing of the gorge in the peripheral site that may impede entry of reactivators. This appears characteristic of acetylcholinesterase inhibition by organophosphate insecticides but not nerve agents. Additional changes seen at the dimer interface are novel and provide further examples of the disruptive effect of paraoxon. Ternary structures of paraoxon-inhibited human acetylcholinesterase in complex with the oximes HI6 and 2-PAM reveals relatively poor positioning for reactivation. This study provides a structural foundation for improved reactivator design for the treatment of organophosphate intoxication. Proteins 2016; 84:1246-1256. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Matthew C Franklin
- Special Projects Group, New York Structural Biology Center, New York, New York, 10027
| | - Michael J Rudolph
- Special Projects Group, New York Structural Biology Center, New York, New York, 10027
| | - Christopher Ginter
- Special Projects Group, New York Structural Biology Center, New York, New York, 10027
| | - Michael S Cassidy
- Special Projects Group, New York Structural Biology Center, New York, New York, 10027
| | - Jonah Cheung
- Special Projects Group, New York Structural Biology Center, New York, New York, 10027
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13
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Allgardsson A, Berg L, Akfur C, Hörnberg A, Worek F, Linusson A, Ekström FJ. Structure of a prereaction complex between the nerve agent sarin, its biological target acetylcholinesterase, and the antidote HI-6. Proc Natl Acad Sci U S A 2016; 113:5514-9. [PMID: 27140636 PMCID: PMC4878515 DOI: 10.1073/pnas.1523362113] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Organophosphorus nerve agents interfere with cholinergic signaling by covalently binding to the active site of the enzyme acetylcholinesterase (AChE). This inhibition causes an accumulation of the neurotransmitter acetylcholine, potentially leading to overstimulation of the nervous system and death. Current treatments include the use of antidotes that promote the release of functional AChE by an unknown reactivation mechanism. We have used diffusion trap cryocrystallography and density functional theory (DFT) calculations to determine and analyze prereaction conformers of the nerve agent antidote HI-6 in complex with Mus musculus AChE covalently inhibited by the nerve agent sarin. These analyses reveal previously unknown conformations of the system and suggest that the cleavage of the covalent enzyme-sarin bond is preceded by a conformational change in the sarin adduct itself. Together with data from the reactivation kinetics, this alternate conformation suggests a key interaction between Glu202 and the O-isopropyl moiety of sarin. Moreover, solvent kinetic isotope effect experiments using deuterium oxide reveal that the reactivation mechanism features an isotope-sensitive step. These findings provide insights into the reactivation mechanism and provide a starting point for the development of improved antidotes. The work also illustrates how DFT calculations can guide the interpretation, analysis, and validation of crystallographic data for challenging reactive systems with complex conformational dynamics.
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Affiliation(s)
- Anders Allgardsson
- Department of CBRN Defence and Security, Swedish Defence Research Agency, SE-90182 Umea, Sweden
| | - Lotta Berg
- Department of Chemistry, Umeå University, SE-90187 Umea, Sweden
| | - Christine Akfur
- Department of CBRN Defence and Security, Swedish Defence Research Agency, SE-90182 Umea, Sweden
| | | | - Franz Worek
- Department of Toxicological Enzymology, Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Anna Linusson
- Department of Chemistry, Umeå University, SE-90187 Umea, Sweden;
| | - Fredrik J Ekström
- Department of CBRN Defence and Security, Swedish Defence Research Agency, SE-90182 Umea, Sweden;
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14
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Pathak AK, Bandyopadhyay T. Ortho-7 bound to the active-site gorge of free and OP-conjugated acetylcholinesterase: cation-π interactions. Biopolymers 2015; 105:10-20. [PMID: 26270602 DOI: 10.1002/bip.22712] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/10/2015] [Accepted: 08/10/2015] [Indexed: 02/02/2023]
Abstract
Despite the immense importance of cation-π interactions prevailing in bispyridinium drug acetylcholinesterase (AChE) complexes, a precise description of cation-π interactions at molecular level has remained elusive. Here, we consider a bispyridinium drug, namely, ortho-7 in three different structures of AChE, with and without complexation with organophosphorus (OP) compounds for detailed investigation using all atom molecular dynamics simulation. By quantum mechanical calculations, Y72, W86, Y124, W286, Y337, and Y341 aromatic residues of the enzyme are investigated for possible cation-π interactions with ortho-7. The cation-π interactions in each of the protein-drug complexes are studied using distance, angle, a suitable functional form of them, and electrostatic criteria. The variation of cation-π functional is remarkably consistent with that of the Columbic variation. It is clearly observed that cation-π interactions for some of the residues in the catalytic active site (CAS) and peripheral anionic site (PAS) of the enzyme are either enhanced or reduced based on the nature of OP conjugation (i.e., nerve gas, tabun or pesticide, fenamiphos) when compared with the OP-free enzyme. The strength of cation-π interaction is strongly dependent on the type OP conjugation. The effect of conjugation at CAS is also seen to influence the cation-π interaction at the PAS region. The variation of cation-π interactions on the type of conjugating OP compounds might be suggestive of a reason as to why wide spectrum drug against any OP poisoning is yet to arrive in the market.
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Affiliation(s)
- Arup Kumar Pathak
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Tusar Bandyopadhyay
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai, 400085, India
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Bennion BJ, Essiz SG, Lau EY, Fattebert JL, Emigh A, Lightstone FC. A wrench in the works of human acetylcholinesterase: soman induced conformational changes revealed by molecular dynamics simulations. PLoS One 2015; 10:e0121092. [PMID: 25874456 PMCID: PMC4395452 DOI: 10.1371/journal.pone.0121092] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 01/27/2015] [Indexed: 01/06/2023] Open
Abstract
Irreversible inactivation of human acetylcholinesterase (hAChE) by organophosphorous pesticides (OPs) and chemical weapon agents (CWA) has severe morbidity and mortality consequences. We present data from quantum mechanics/molecular mechanics (QM/MM) and 80 classical molecular dynamics (MD) simulations of the apo and soman-adducted forms of hAChE to investigate the effects on the dynamics and protein structure when the catalytic Serine 203 is phosphonylated. We find that the soman phosphonylation of the active site Ser203 follows a water assisted addition-elimination mechanism with the elimination of the fluoride ion being the highest energy barrier at 6.5 kcal/mole. We observe soman-dependent changes in backbone and sidechain motions compared to the apo form of the protein. These alterations restrict the soman-adducted hAChE to a structural state that is primed for the soman adduct to be cleaved and removed from the active site. The altered motions and resulting structures provide alternative pathways into and out of the hAChE active site. In the soman-adducted protein both side and back door pathways are viable for soman adduct access. Correlation analysis of the apo and soman adducted MD trajectories shows that the correlation of gorge entrance and back door motion is disrupted when hAChE is adducted. This supports the hypothesis that substrate and product can use two different pathways as entry and exit sites in the apo form of the protein. These alternative pathways have important implications for the rational design of medical countermeasures.
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Affiliation(s)
- Brian J. Bennion
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore CA, United States of America
| | - Sebnem G. Essiz
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083 Fatih, Istanbul, Turkey
| | - Edmond Y. Lau
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore CA, United States of America
| | - Jean-Luc Fattebert
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore CA, United States of America
| | - Aiyana Emigh
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore CA, United States of America
| | - Felice C. Lightstone
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore CA, United States of America
- * E-mail:
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16
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Rezg R, Mornagui B, Santos JSDO, Dulin F, El-Fazaa S, Ben El-Haj N, Bureau R, Gharbi N. Protective effects of caffeic acid against hypothalamic neuropeptides alterations induced by malathion in rat. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:6198-6207. [PMID: 25404496 DOI: 10.1007/s11356-014-3824-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 11/05/2014] [Indexed: 06/04/2023]
Abstract
Exposure to pesticides is suspected to cause human health problems. Our study aimed to evaluate preventive effects of caffeic acid (3,4-dihydroxycinnamic acid) in the hypothalamus against malathion-induced neuropeptides gene expression alterations. Malathion at 100 mg/kg was administered intragastrically to rats alone or in combination with caffeic acid at 100 mg/kg during 4 weeks. A molecular expression of hypothalamic neuropeptides and plasmatic cholinesterase activity was investigated. Furthermore, we used in silico analysis, known as computational docking, to highlight the nature of acetylcholinesterase-malathion/caffeic acid interactions. Our findings showed differences in the responses and indicate that caffeic acid reversed malathion-induced decrease in corticotropin-releasing hormone mRNA but not brain-derived neurotrophic factor which presented an increased tendency. We suggest that caffeic acid can interact with acetylcholinesterase as the primary target of organophosphorus compounds. Results predict that caffeic acid can block partly the acetylcholinesterase gorge entrance via π-π stacking interaction with Tyr 124 and Trp 286 residues of the peripheral site leading to its stricture. Under this condition, we suggested that acetylcholine trafficking toward the catalytic site is ameliorated compared to malaoxon according to their sizes.
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Affiliation(s)
- Raja Rezg
- Laboratoire de Physiologie des Agressions, Département de Biologie, Faculté des Sciences de Tunis, Université El Manar, Tunis, Tunisie
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17
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Wymore T, Field MJ, Langan P, Smith JC, Parks JM. Hydrolysis of DFP and the nerve agent (S)-sarin by DFPase proceeds along two different reaction pathways: implications for engineering bioscavengers. J Phys Chem B 2014; 118:4479-89. [PMID: 24720808 PMCID: PMC4010294 DOI: 10.1021/jp410422c] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
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Organophosphorus
(OP) nerve agents such as (S)-sarin
are among the most highly toxic compounds that have been synthesized.
Engineering enzymes that catalyze the hydrolysis of nerve agents (“bioscavengers”)
is an emerging prophylactic approach to diminish their toxic effects.
Although its native function is not known, diisopropyl fluorophosphatase
(DFPase) from Loligo vulgaris catalyzes
the hydrolysis of OP compounds. Here, we investigate the mechanisms
of diisopropylfluorophosphate (DFP) and (S)-sarin
hydrolysis by DFPase with quantum mechanical/molecular mechanical
umbrella sampling simulations. We find that the mechanism for hydrolysis
of DFP involves nucleophilic attack by Asp229 on phosphorus to form
a pentavalent intermediate. P–F bond dissociation then yields
a phosphoacyl enzyme intermediate in the rate-limiting step. The simulations
suggest that a water molecule, coordinated to the catalytic Ca2+, donates a proton to Asp121 and then attacks the tetrahedral
phosphoacyl intermediate to liberate the diisopropylphosphate product.
In contrast, the calculated free energy barrier for hydrolysis of
(S)-sarin by the same mechanism is highly unfavorable,
primarily because of the instability of the pentavalent phosphoenzyme
species. Instead, simulations suggest that hydrolysis of (S)-sarin proceeds by a mechanism in which Asp229 could activate
an intervening water molecule for nucleophilic attack on the substrate.
These findings may lead to improved strategies for engineering DFPase
and related six-bladed β-propeller folds for more efficient
degradation of OP compounds.
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Affiliation(s)
- Troy Wymore
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831-6309, United States
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Pathak AK, Bandyopadhyay T. Unbinding free energy of acetylcholinesterase bound oxime drugs along the gorge pathway from metadynamics-umbrella sampling investigation. Proteins 2014; 82:1799-818. [PMID: 24549829 DOI: 10.1002/prot.24533] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 01/17/2014] [Accepted: 01/28/2014] [Indexed: 12/20/2022]
Abstract
Because of the pivotal role that the nerve enzyme, acetylcholinesterase plays in terminating nerve impulses at cholinergic synapses. Its active site, located deep inside a 20 Å gorge, is a vulnerable target of the lethal organophosphorus compounds. Potent reactivators of the intoxicated enzyme are nucleophiles, such as bispyridinium oxime that binds to the peripheral anionic site and the active site of the enzyme through suitable cation-π interactions. Atomic scale molecular dynamics and free energy calculations in explicit water are used to study unbinding pathways of two oxime drugs (Ortho-7 and Obidoxime) from the gorge of the enzyme. The role of enzyme-drug cation-π interactions are explored with the metadynamics simulation. The metadynamics discovered potential of mean force (PMF) of the unbinding events is refined by the umbrella sampling (US) corrections. The bidimensional free energy landscape of the metadynamics runs are further subjected to finite temperature string analysis to obtain the transition tube connecting the minima and bottlenecks of the unbinding pathway. The PMF is also obtained from US simulations using the biasing potential constructed from the transition tube and are found to be consistent with the metadynamics-US corrected results. Although experimental structural data clearly shows analogous coordination of the two drugs inside the gorge in the bound state, the PMF of the drug trafficking along the gorge pathway point, within an equilibrium free energy context, to a multistep process that differs from one another. Routes, milestones and subtlety toward the unbinding pathway of the two oximes at finite temperature are identified.
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Affiliation(s)
- Arup K Pathak
- Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India
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Lo R, Chandar NB, Kesharwani MK, Jain A, Ganguly B. In silico studies in probing the role of kinetic and structural effects of different drugs for the reactivation of tabun-inhibited AChE. PLoS One 2013; 8:e79591. [PMID: 24312449 PMCID: PMC3846473 DOI: 10.1371/journal.pone.0079591] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 09/27/2013] [Indexed: 11/24/2022] Open
Abstract
We have examined the reactivation mechanism of the tabun-conjugated AChE with various drugs using density functional theory (DFT) and post-Hartree-Fock methods. The electronic environments and structural features of neutral oximes (deazapralidoxime and 3-hydroxy-2-pyridinealdoxime) and charged monopyridinium oxime (2-PAM) and bispyridinium oxime (Ortho-7) are different, hence their efficacy varies towards the reactivation process of tabun-conjugated AChE. The calculated potential energy surfaces suggest that a monopyridinium reactivator is less favorable for the reactivation of tabun-inhibited AChE compared to a bis-quaternary reactivator, which substantiates the experimental study. The rate determining barrier with neutral oximes was found to be ∼2.5 kcal/mol, which was ∼5.0 kcal/mol lower than charged oxime drugs such as Ortho-7. The structural analysis of the calculated geometries suggest that the charged oximes form strong O…H and N…H hydrogen bonding and C-H…π non-bonding interaction with the tabun-inhibited enzyme to stabilize the reactant complex compared to separated reactants, which influences the activation barrier. The ability of neutral drugs to cross the blood-brain barrier was also found to be superior to charged antidotes, which corroborates the available experimental observations. The calculated activation barriers support the superiority of neutral oximes for the activation of tabun-inhibited AChE compared to charged oximes. However, they lack effective interactions with their peripheral sites. Docking studies revealed that the poor binding affinity of simple neutral oxime drugs such as 3-hydroxy-2-pyridinealdoxime inside the active-site gorge of AChE was significantly augmented with the addition of neutral peripheral units compared to conventional charged peripheral sites. The newly designed oxime drug 2 appears to be an attractive candidate as efficient antidote to kinetically and structurally reactivate the tabun-inhibited enzyme.
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Affiliation(s)
- Rabindranath Lo
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, India
| | - Nellore Bhanu Chandar
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, India
- Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar, Gujarat, India
| | - Manoj K. Kesharwani
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, India
| | - Aastha Jain
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, India
| | - Bishwajit Ganguly
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility), CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat, India
- Academy of Scientific and Innovative Research, CSIR-CSMCRI, Bhavnagar, Gujarat, India
- * E-mail:
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20
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Carletti E, Colletier JP, Schopfer LM, Santoni G, Masson P, Lockridge O, Nachon F, Weik M. Inhibition Pathways of the Potent Organophosphate CBDP with Cholinesterases Revealed by X-ray Crystallographic Snapshots and Mass Spectrometry. Chem Res Toxicol 2013; 26:280-9. [DOI: 10.1021/tx3004505] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eugénie Carletti
- Institut de Biologie Structurale
J.P. Ebel, Commissariat à l’Energie Atomique, 41, rue Jules Horowitz, F-38027 Grenoble, France
- CNRS, UMR5075, F-38027 Grenoble,
France
- Université Joseph Fourier, F-38000 Grenoble, France
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, 24 avenue des Marquis du Grésivaudan, 38702 La Tronche,
France
| | - Jacques-Philippe Colletier
- Institut de Biologie Structurale
J.P. Ebel, Commissariat à l’Energie Atomique, 41, rue Jules Horowitz, F-38027 Grenoble, France
- CNRS, UMR5075, F-38027 Grenoble,
France
- Université Joseph Fourier, F-38000 Grenoble, France
| | - Lawrence M. Schopfer
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska
68198-5950, United States
| | - Gianluca Santoni
- Institut de Biologie Structurale
J.P. Ebel, Commissariat à l’Energie Atomique, 41, rue Jules Horowitz, F-38027 Grenoble, France
- CNRS, UMR5075, F-38027 Grenoble,
France
- Université Joseph Fourier, F-38000 Grenoble, France
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, 24 avenue des Marquis du Grésivaudan, 38702 La Tronche,
France
| | - Patrick Masson
- Institut de Biologie Structurale
J.P. Ebel, Commissariat à l’Energie Atomique, 41, rue Jules Horowitz, F-38027 Grenoble, France
- CNRS, UMR5075, F-38027 Grenoble,
France
- Université Joseph Fourier, F-38000 Grenoble, France
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, 24 avenue des Marquis du Grésivaudan, 38702 La Tronche,
France
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska
68198-5950, United States
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska
68198-5950, United States
| | - Florian Nachon
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, 24 avenue des Marquis du Grésivaudan, 38702 La Tronche,
France
| | - Martin Weik
- Institut de Biologie Structurale
J.P. Ebel, Commissariat à l’Energie Atomique, 41, rue Jules Horowitz, F-38027 Grenoble, France
- CNRS, UMR5075, F-38027 Grenoble,
France
- Université Joseph Fourier, F-38000 Grenoble, France
- ESRF, 6
rue Jules Horowitz, BP 220, 38043 Grenoble Cedex, France
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21
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Mercey G, Verdelet T, Renou J, Kliachyna M, Baati R, Nachon F, Jean L, Renard PY. Reactivators of acetylcholinesterase inhibited by organophosphorus nerve agents. Acc Chem Res 2012; 45:756-66. [PMID: 22360473 DOI: 10.1021/ar2002864] [Citation(s) in RCA: 245] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Since the September 11, 2001, terrorist attacks in the United States, the specter of a chemical threat against civilian populations has renewed research interest in chemical warfare agents, their mechanisms of action, and treatments that reverse their effects. In this Account, we focus specifically on organophosphorus nerve agents (OPNAs). Although some OPNAs are used as pest control, the most toxic chemicals in this class are used as chemical warfare agents in armed conflicts. The acute toxicity of OPNAs results from the irreversible inhibition of acetylcholinesterase (AChE, EC 3.1.1.7) via the formation of a covalent P-O bond at the serine hydroxyl group in the enzyme active site. AChE breaks down the neurotransmitter acetylcholine at neuronal synapses and neuromuscular junctions. The irreversible inhibition of AChE causes the neurotransmitter to accumulate in the synaptic cleft, leading to overstimulation of cholinergic receptors, seizures, respiratory arrest, and death. The current treatment for OPNA poisoning combines an antimuscarinic drug (e.g., atropine), an anticonvulsant drug (e.g., diazepam), and an AChE reactivator of the pyridinium aldoxime family (pralidoxime, trimedoxime, obidoxime, HI-6, HLö-7). Because of their high nucleophilicity, oximes can displace the phosphyl group from the catalytic serine, thus restoring the enzyme's catalytic activity. During 50 years of research in the reactivator field, researchers have synthesized and tested numerous structural modifications of monopyridinium oximes and bispyridinium oximes. In the past decade, medicinal chemists have focused their research on the more efficient bispyridinium reactivators, but all known reactivators have several drawbacks. First, due to their permanent positive charge, they do not cross the blood-brain barrier (BBB) efficiently and do not readily reactivate AChE in the central nervous system. Second, no single oxime is efficient against a wide variety of OPNAs. Third, oximes cannot reactivate "aged" AChE. This Account summarizes recent strategies for the development of AChE reactivators capable of crossing the BBB. The use of nanoparticulate transport and inhibition of P-glycoprotein efflux pumps improves BBB transport of these AChE reactivators. Chemical modifications that increased the lipophilicity of the pyridinium aldoximes, the addition of a fluorine atom and the replacement of a pyridyl ring with a dihydropyridyl moiety, enhances BBB permeability. The glycosylation of pyridine aldoximes facilitates increased BBB penetration via the GLUT-1 transport system. The development of novel uncharged reactivators that can move efficiently across the BBB represents one of the most promising of these new strategies.
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Affiliation(s)
- Guillaume Mercey
- Equipe de Chimie Bio-Organique, COBRA - CNRS UMR 6014 & FR 3038, Rue Lucien Tesnière, 76131 Mont-Saint-Aignan, France
- Université de Rouen, Place Emile Blondel, 76821, Mont-Saint-Aignan, France
| | - Tristan Verdelet
- Equipe de Chimie Bio-Organique, COBRA - CNRS UMR 6014 & FR 3038, Rue Lucien Tesnière, 76131 Mont-Saint-Aignan, France
- Université de Rouen, Place Emile Blondel, 76821, Mont-Saint-Aignan, France
| | - Julien Renou
- Equipe de Chimie Bio-Organique, COBRA - CNRS UMR 6014 & FR 3038, Rue Lucien Tesnière, 76131 Mont-Saint-Aignan, France
- Université de Rouen, Place Emile Blondel, 76821, Mont-Saint-Aignan, France
| | - Maria Kliachyna
- Faculté de Pharmacie, Université de Strasbourg, CNRS UMR 7199, Laboratoire des Systèmes Chimiques Fonctionnels, 74 route du Rhin, BP 60024, 67401 Illkirch, France
| | - Rachid Baati
- Faculté de Pharmacie, Université de Strasbourg, CNRS UMR 7199, Laboratoire des Systèmes Chimiques Fonctionnels, 74 route du Rhin, BP 60024, 67401 Illkirch, France
| | - Florian Nachon
- Département de Toxicologie, Institut de Recherche Biomédicale des Armées, 24 Avenue des Maquis du Grésivaudan, BP87, 38702 La Tronche, France
| | - Ludovic Jean
- Equipe de Chimie Bio-Organique, COBRA - CNRS UMR 6014 & FR 3038, Rue Lucien Tesnière, 76131 Mont-Saint-Aignan, France
- Université de Rouen, Place Emile Blondel, 76821, Mont-Saint-Aignan, France
| | - Pierre-Yves Renard
- Equipe de Chimie Bio-Organique, COBRA - CNRS UMR 6014 & FR 3038, Rue Lucien Tesnière, 76131 Mont-Saint-Aignan, France
- Université de Rouen, Place Emile Blondel, 76821, Mont-Saint-Aignan, France
- Institut Universitaire de France, 103 Boulevard Saint Michel, 75005 Paris, France
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22
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Ronco C, Carletti E, Colletier JP, Weik M, Nachon F, Jean L, Renard PY. Huprine Derivatives as Sub-Nanomolar Human Acetylcholinesterase Inhibitors: From Rational Design to Validation by X-ray Crystallography. ChemMedChem 2011; 7:400-5. [DOI: 10.1002/cmdc.201100438] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Indexed: 11/06/2022]
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23
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Masson P. Evolution of and perspectives on therapeutic approaches to nerve agent poisoning. Toxicol Lett 2011; 206:5-13. [PMID: 21524695 DOI: 10.1016/j.toxlet.2011.04.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 04/08/2011] [Indexed: 01/18/2023]
Abstract
After more than 70 years of considerable efforts, research on medical defense against nerve agents has come to a standstill. Major progress in medical countermeasures was achieved between the 50s and 70s with the development of anticholinergic drugs and carbamate-based pretreatment, the introduction of pyridinium oximes as antidotes, and benzodiazepines in emergency treatments. These drugs ensure good protection of the peripheral nervous system and mitigate the acute effects of exposure to lethal doses of nerve agents. However, pyridostigmine and cholinesterase reactivators currently used in the armed forces do not protect/reactivate central acetylcholinesterases. Moreover, other drugs used are not sufficiently effective in protecting the central nervous system against seizures, irreversible brain damages and long-term sequelae of nerve agent poisoning.New developments of medical counter-measures focus on: (a) detoxification of organophosphorus molecules before they react with acetylcholinesterase and other physiological targets by administration of stoichiometric or catalytic scavengers; (b) protection and reactivation of central acetylcholinesterases, and (c) improvement of neuroprotection following delayed therapy.Future developments will aim at treatment of acute and long-term effects of low level exposure to nerve agents, research on alternative routes for optimizing drug delivery, and therapies. Though gene therapy for in situ generation of bioscavengers, and cell therapy based on neural progenitor engraftment for neuronal regeneration have been successfully explored, more studies are needed before practical medical applications can be made of these new approaches.
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Affiliation(s)
- Patrick Masson
- IRBA-CRSSA, Toxicology Dept., 38702 La Tronche Cedex, France.
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24
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Musilek K, Komloova M, Holas O, Horova A, Pohanka M, Gunn-Moore F, Dohnal V, Dolezal M, Kuca K. Mono-oxime bisquaternary acetylcholinesterase reactivators with prop-1,3-diyl linkage—Preparation, in vitro screening and molecular docking. Bioorg Med Chem 2011; 19:754-62. [DOI: 10.1016/j.bmc.2010.12.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 12/05/2010] [Accepted: 12/07/2010] [Indexed: 11/30/2022]
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25
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Structural approach to the aging of phosphylated cholinesterases. Chem Biol Interact 2010; 187:157-62. [DOI: 10.1016/j.cbi.2010.03.027] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2009] [Revised: 03/08/2010] [Accepted: 03/12/2010] [Indexed: 12/18/2022]
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26
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Nachon F, Carletti E, Worek F, Masson P. Aging mechanism of butyrylcholinesterase inhibited by an N-methyl analogue of tabun: implications of the trigonal-bipyramidal transition state rearrangement for the phosphylation or reactivation of cholinesterases. Chem Biol Interact 2010; 187:44-8. [PMID: 20381476 DOI: 10.1016/j.cbi.2010.03.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 03/19/2010] [Accepted: 03/31/2010] [Indexed: 11/28/2022]
Abstract
Cholinesterases are the main target of organophosphorus nerve agents (OPs). Their inhibition results in cholinergic syndrome and death. The enzymes are inhibited by phosphylation of the catalytic serine enzyme, but can be reactivated by oximes to some extent. However, phosphylated cholinesterases undergo a side reaction that progressively prevents their reactivatability. This unimolecular reaction, termed "aging", has been investigated for decades. It was shown that most OP-ChE conjugates aged by O-dealkylation of an alkoxy substituent of the phosphorus atom, a mechanism involving the stabilization of a transient carbocation. In this paper we present structural data supporting a substitution-based mechanism for aging of the huBChE conjugate of an N-mono-methyl analogue of tabun. This mechanism involves an adjacent nucleophilic attack followed by Berry pseudorotation. A similar adjacent attack and subsequent rearrangement of the transition state have been recently proposed for tabun phosphylation of AChE. We suggest that a similar mechanism is also possible for oxime reactivation of phosphylated cholinesterases. This opens new perspectives in terms of reactivator design.
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Affiliation(s)
- Florian Nachon
- Département de Toxicologie, Centre de Recherches du Service de Santé des Armées (CRSSA), 38702 La Tronche Cedex, France.
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