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Durmaz K, Misbach M, Danoy A, Salvi JP, Bloch E, Bourrelly S, Verrier B, Sohier J. An innovative Fuller's earth-based film-forming formulation for skin decontamination, through removal and entrapment of an organophosphorus compound, paraoxon-ethyl. J Hazard Mater 2024; 470:134190. [PMID: 38593659 DOI: 10.1016/j.jhazmat.2024.134190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/11/2024]
Abstract
Organophosphorus compounds (OPs), such as VX, pose a significant threat due to their neurotoxic and hazardous properties. Skin decontamination is essential to avoid irreversible effects. Fuller's earth (FE), a phyllosilicate conventionally employed in powder form, has demonstrated decontamination capacity against OPs. The aim of this study was to develop a formulation that forms a film on the skin, with a significant OP removal capacity (>95 %) coupled with sequestration capabilities, favorable drying time and mechanical properties to allow for easy application and removal, particularly in emergency context. Various formulations were prepared using different concentrations of polyvinyl alcohol (PVA), FE and surfactants. Their removal and sequestration capacity was tested using paraoxon-ethyl (POX), a chemical that simulates the behavior of VX. Formulations with removal capacity levels surpassing 95 % were mechanically characterized and cell viability assays were performed on Normal Human Dermal Fibroblast (NHDF). The four most promising formulations were used to assess decontamination efficacy on pig ear skin explants. These formulations showed decontamination levels ranging from 84.4 ± 4.7 % to 96.5 ± 1.3 %, which is equivalent to current decontamination methods. These results suggest that this technology could be a novel and effective tool for skin decontamination following exposure to OPs.
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Affiliation(s)
- Kardelen Durmaz
- UMR 5305: Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, CNRS/Université Claude Bernard Lyon 1, 8 avenue Rockefeller, 69008 Lyon, France
| | - Magaly Misbach
- UMR 5305: Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, CNRS/Université Claude Bernard Lyon 1, 8 avenue Rockefeller, 69008 Lyon, France
| | - Alix Danoy
- UMR 5305: Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, CNRS/Université Claude Bernard Lyon 1, 8 avenue Rockefeller, 69008 Lyon, France
| | - Jean-Paul Salvi
- UMR 5305: Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, CNRS/Université Claude Bernard Lyon 1, 8 avenue Rockefeller, 69008 Lyon, France
| | - Emily Bloch
- UMR 7246: Laboratoire MADIREL, CNRS/Université Aix-Marseille, 52 avenue Escadrille Normandie - Niemen, 13013 Marseille, France
| | - Sandrine Bourrelly
- UMR 7246: Laboratoire MADIREL, CNRS/Université Aix-Marseille, 52 avenue Escadrille Normandie - Niemen, 13013 Marseille, France
| | - Bernard Verrier
- UMR 5305: Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, CNRS/Université Claude Bernard Lyon 1, 8 avenue Rockefeller, 69008 Lyon, France
| | - Jerome Sohier
- UMR 5305: Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, CNRS/Université Claude Bernard Lyon 1, 8 avenue Rockefeller, 69008 Lyon, France.
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2
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Kashapov R, Razuvayeva Y, Ziganshina A, Salnikov V, Zakharova L. A supramolecular catalyst based on sodium alginate and viologen calix[4]resorcinol for the room temperature hydrolysis of paraoxon. Int J Biol Macromol 2024; 257:128578. [PMID: 38048928 DOI: 10.1016/j.ijbiomac.2023.128578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/10/2023] [Accepted: 12/01/2023] [Indexed: 12/06/2023]
Abstract
Properties of paraoxon, such as poor water solubility, low rate of natural decomposition, ability to accumulate in soil and wastewater, lead to the fact that paraoxon is found in various agricultural products and textiles. In this regard, the search for effective ways of paraoxon degradation becomes an extremely urgent problem, which can be solved by creating catalysts by mimicking paraxonase. In this work, a complex of physicochemical methods was used to study the supramolecular interactions of sodium alginate, which has a calcium-binding ability similar to paraxonase, with viologen calix[4]resorcinol and to reveal the nature of the intermolecular interactions between them resulting in the spontaneous formation of nanoparticles. Before proceeding to the investigation of the binding ability of obtained nanoparticles to paraoxon, the encapsulating effect of nanoparticles on a number of model substrates of different solubility (doxorubicin hydrochloride, quercetin and oleic acid) was studied. The kinetics of paraoxon hydrolysis reaction using these nanoparticles was studied at room temperature in an aqueous medium by spectrophotometric method. The rate of this reaction increases with increasing concentration of stable nanoparticles having hydrophobic domains that ensure paraoxon immobilization. The results obtained allow considering the supramolecular polysaccharide/calixarene system as an effective biomimetic catalyst.
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Affiliation(s)
- Ruslan Kashapov
- A.E. Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of the Russian Academy of Sciences, 8 Arbuzov str., 420088 Kazan, Russia.
| | - Yuliya Razuvayeva
- A.E. Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of the Russian Academy of Sciences, 8 Arbuzov str., 420088 Kazan, Russia
| | - Albina Ziganshina
- A.E. Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of the Russian Academy of Sciences, 8 Arbuzov str., 420088 Kazan, Russia
| | - Vadim Salnikov
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of the Russian Academy of Sciences, 2 Lobachevsky str., 420111 Kazan, Russia
| | - Lucia Zakharova
- A.E. Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center of the Russian Academy of Sciences, 8 Arbuzov str., 420088 Kazan, Russia
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3
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Pirollo KF, Moghe M, Guan M, Rait AS, Wang A, Kim SS, Chang EH, Harford JB. A Pralidoxime Nanocomplex Formulation Targeting Transferrin Receptors for Reactivation of Brain Acetylcholinesterase After Exposure of Mice to an Anticholinesterase Organophosphate. Int J Nanomedicine 2024; 19:307-326. [PMID: 38229703 PMCID: PMC10790653 DOI: 10.2147/ijn.s443498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 12/25/2023] [Indexed: 01/18/2024] Open
Abstract
Introduction Organophosphates are among the deadliest of known chemicals based on their ability to inactivate acetylcholinesterase in neuromuscular junctions and synapses of the central and peripheral nervous systems. The consequent accumulation of acetylcholine can produce severe acute toxicities and death. Oxime antidotes act by reactivating acetylcholinesterase with the only such reactivator approved for use in the United States being 2-pyridine aldoxime methyl chloride (a.k.a., pralidoxime or 2-PAM). However, this compound does not cross the blood-brain barrier readily and so is limited in its ability to reactivate acetylcholinesterase in the brain. Methods We have developed a novel formulation of 2-PAM by encapsulating it within a nanocomplex designed to cross the blood-brain barrier via transferrin receptor-mediated transcytosis. This nanocomplex (termed scL-2PAM) has been subjected to head-to-head comparisons with unencapsulated 2-PAM in mice exposed to paraoxon, an organophosphate with anticholinesterase activity. Results and Discussion In mice exposed to a sublethal dose of paraoxon, scL-2PAM reduced the extent and duration of cholinergic symptoms more effectively than did unencapsulated 2-PAM. The scL-2PAM formulation was also more effective than unencapsulated 2-PAM in rescuing mice from death after exposure to otherwise-lethal levels of paraoxon. Improved survival rates in paraoxon-exposed mice were accompanied by a higher degree of reactivation of brain acetylcholinesterase. Conclusion Our data indicate that scL-2PAM is superior to the currently used form of 2-PAM in terms of both mitigating paraoxon toxicity in mice and reactivating acetylcholinesterase in their brains.
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Affiliation(s)
- Kathleen F Pirollo
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Manish Moghe
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Miaoyin Guan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Antonina S Rait
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Aibing Wang
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Sang-Soo Kim
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
- SynerGene Therapeutics, Inc., Potomac, MD, 20854, USA
| | - Esther H Chang
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Joe B Harford
- SynerGene Therapeutics, Inc., Potomac, MD, 20854, USA
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Hoyano Y, Tamashiro I, Akimoto T. Fusion proteins of organophosphorus hydrolase and pHluorin for a whole-cell biosensor for organophosphorus pesticide measurement. ANAL SCI 2023; 39:1515-1520. [PMID: 37264267 DOI: 10.1007/s44211-023-00369-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 05/15/2023] [Indexed: 06/03/2023]
Abstract
Fusion proteins composed of an organophosphorus hydrolase (OPH) and pHluorin, a pH-sensitive green fluorescent protein variant, were constructed as whole-cell biosensors to measure organophosphorus pesticides. pHluorin was used to detect the pH changes because of the hydrolase of paraoxon by OPH. To examine the order of fusion of OPH and pHluorin, pHluorin-OPH and OPH-pHluorin fusion proteins were constructed. In addition, a peptide linker consisting of 15 amino acid was inserted between pHluorin and OPH to reduce steric hindrance. OPH and pHluorin activities were evaluated in cells expressing the four fusion proteins. The both activities of pHluorin-OPH and pHluorin-linker-OPH were higher than that of OPH-pHluorin and OPH-linker-pHluorin. Effects of the peptide linker on the activities were slight. Therefore, pHluorin-OPH and pHluorin-linker-OPH were found to be suitable for organophosphorus pesticide measurements. Using cells expressing pHluorin-linker-OPH, 0.5 μg/mL of paraoxon could be measured.
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Affiliation(s)
- Yusei Hoyano
- School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo, 192-0982, Japan
| | - Issa Tamashiro
- School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo, 192-0982, Japan
| | - Takuo Akimoto
- School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo, 192-0982, Japan.
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Gerlits O, Fajer M, Cheng X, Blumenthal DK, Radić Z, Kovalevsky A. Structural and dynamic effects of paraoxon binding to human acetylcholinesterase by X-ray crystallography and inelastic neutron scattering. Structure 2022; 30:1538-1549.e3. [PMID: 36265484 PMCID: PMC9637784 DOI: 10.1016/j.str.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/07/2022] [Accepted: 09/25/2022] [Indexed: 11/06/2022]
Abstract
Organophosphorus (OP) compounds, including nerve agents and some pesticides, covalently bind to the catalytic serine of human acetylcholinesterase (hAChE), thereby inhibiting acetylcholine hydrolysis necessary for efficient neurotransmission. Oxime antidotes can reactivate the OP-conjugated hAChE, but reactivation efficiency can be low for pesticides, such as paraoxon (POX). Understanding structural and dynamic determinants of OP inhibition and reactivation can provide insights to design improved reactivators. Here, X-ray structures of hAChE with unaged POX, with POX and oximes MMB4 and RS170B, and with MMB4 are reported. A significant conformational distortion of the acyl loop was observed upon POX binding, being partially restored to the native conformation by oximes. Neutron vibrational spectroscopy combined with molecular dynamics simulations showed that picosecond vibrational dynamics of the acyl loop soften in the ∼20-50 cm-1 frequency range. The acyl loop structural perturbations may be correlated with its picosecond vibrational dynamics to yield more comprehensive template for structure-based reactivator design.
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Affiliation(s)
- Oksana Gerlits
- Department of Natural Sciences, Tennessee Wesleyan University, Athens, TN 37303, USA
| | - Mikolai Fajer
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xiaolin Cheng
- Division of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Donald K Blumenthal
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Zoran Radić
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0657, USA.
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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El Khoury L, Mobley DL, Ye D, Rempe SB. Enhancing Paraoxon Binding to Organophosphorus Hydrolase Active Site. Int J Mol Sci 2021; 22:12624. [PMID: 34884430 PMCID: PMC8657610 DOI: 10.3390/ijms222312624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/12/2021] [Accepted: 11/14/2021] [Indexed: 11/16/2022] Open
Abstract
Organophosphorus hydrolase (OPH) is a metalloenzyme that can hydrolyze organophosphorus agents resulting in products that are generally of reduced toxicity. The best OPH substrate found to date is diethyl p-nitrophenyl phosphate (paraoxon). Most structural and kinetic studies assume that the binding orientation of paraoxon is identical to that of diethyl 4-methylbenzylphosphonate, which is the only substrate analog co-crystallized with OPH. In the current work, we used a combined docking and molecular dynamics (MD) approach to predict the likely binding mode of paraoxon. Then, we used the predicted binding mode to run MD simulations on the wild type (WT) OPH complexed with paraoxon, and OPH mutants complexed with paraoxon. Additionally, we identified three hot-spot residues (D253, H254, and I255) involved in the stability of the OPH active site. We then experimentally assayed single and double mutants involving these residues for paraoxon binding affinity. The binding free energy calculations and the experimental kinetics of the reactions between each OPH mutant and paraoxon show that mutated forms D253E, D253E-H254R, and D253E-I255G exhibit enhanced substrate binding affinity over WT OPH. Interestingly, our experimental results show that the substrate binding affinity of the double mutant D253E-H254R increased by 19-fold compared to WT OPH.
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Affiliation(s)
- Léa El Khoury
- Department of Pharmaceutical Sciences, University of California, Irvine, CA 92697, USA; (L.E.K.); (D.L.M.)
| | - David L. Mobley
- Department of Pharmaceutical Sciences, University of California, Irvine, CA 92697, USA; (L.E.K.); (D.L.M.)
- Department of Chemistry, University of California, Irvine, CA 92697, USA
| | - Dongmei Ye
- Sandia National Laboratories, Albuquerque, NM 87123, USA
| | - Susan B. Rempe
- Sandia National Laboratories, Albuquerque, NM 87123, USA
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Liao Y, Sheridan T, Liu J, Farha O, Hupp J. Product Inhibition and the Catalytic Destruction of a Nerve Agent Simulant by Zirconium-Based Metal-Organic Frameworks. ACS Appl Mater Interfaces 2021; 13:30565-30575. [PMID: 34161064 DOI: 10.1021/acsami.1c05062] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rapid degradation/destruction of chemical warfare agents, especially ones containing a phosphorous-fluorine bond, is of notable interest due to their extreme toxicity and typically rapid rate of human incapacitation. Recent studies of the hydrolytic destruction of a key nerve agent simulant, dimethyl 4-nitrophenylphosphate (DMNP), catalyzed by Zr6-based metal-organic frameworks (MOFs), have suggested deactivation of the active sites due to inhibition by the products as the reaction progresses. In this study, the interactions of two MOFs, NU-1000 and MOF-808, and two hydrolysis products, dimethyl phosphate (DMP) and ethyl methyl phosphonate (EMP), from the hydrolysis of the simulant (DMNP) and nerve agent ethyl methylphosphonofluoridate (EMPF), resembling the hydrolysis degradation product of the G-series nerve agent, Sarin (GB), have been investigated to deconvolute the effect of product inhibition from other effects on catalytic activity. Kinetic studies via in situ nuclear magnetic resonance spectroscopy indicated substantial product inhibition upon catalyst activity after several tens to several thousand turnovers, depending on specific conditions. Apparent product binding constants were obtained by fitting initial reaction rates at pH 7.0 and pH 10.5 to a Langmuir-Freundlich binding/adsorption model. For the fits, varying amounts/concentrations of candidate inhibitors were introduced before the start of catalytic hydrolysis. The derived binding constants proved suitable for quantitatively describing product inhibition effects upon reaction rates over the extended time course of simulant hydrolysis by aqua-ligand-bearing hexa-zirconium(IV) nodes.
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Affiliation(s)
- Yijun Liao
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Thomas Sheridan
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Jian Liu
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Omar Farha
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Joseph Hupp
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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Song L, Zhao T, Yang D, Wang X, Hao X, Liu Y, Zhang S, Yu ZZ. Photothermal graphene/UiO-66-NH 2 fabrics for ultrafast catalytic degradation of chemical warfare agent simulants. J Hazard Mater 2020; 393:122332. [PMID: 32120207 DOI: 10.1016/j.jhazmat.2020.122332] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/01/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Lightweight and wearable fabrics with rapid self-detoxification functions are highly desired to resist chemical warfare agents (CWAs). Metal organic frameworks (MOFs) with high specific surface area and customizability are singularly attractive because of their ability to effectively capture and catalytically degrade CWAs. Herein, photothermal graphene-based nanocomposite fabrics are designed by wet-spinning and chemical reduction of graphene oxide fibers followed by in situ growth of UiO-66-NH2. The flexible graphene fabrics decorated with UiO-66-NH2 nanoparticles exhibit an ultrafast photothermal catalytic decontamination of dimethyl 4-nitrophenyl phosphate (DMNP), a typical simulant of CWAs. The half-life of the degradation reaction decreases from 3.4 to 1.6 min under simulated solar light irradiation, a significant gain over the values reported in the literature. Furthermore, DMNP can be degraded in 20 min by the graphene/UiO-66-NH2 fabric, and even after 5 cycles the degradation efficiency still retains more than 92 %. More importantly, the photothermal conversion of graphene and its instantaneous heat transfer to the UiO-66-NH2 catalyst effectively accelerate the catalytic reaction kinetics, achieving the fast detoxification of DMNP. The combination of catalytic degradation of MOFs with photothermal conversion effect of graphene makes the lightweight and flexible fabrics promising for protection against CWAs and other pollutants.
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Affiliation(s)
- Linna Song
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China; State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Tianyu Zhao
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China; State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Dongzhi Yang
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Xuejiao Wang
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xinmin Hao
- China Hemp Research Center, 28 Xizhimen North Avenue, Haidian District, Beijing 100082, China
| | - Yaxin Liu
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Shiyi Zhang
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhong-Zhen Yu
- Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China; State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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Yamaguchi U, Ogawa M, Takei H. Patterned Superhydrophobic SERS Substrates for Sample Pre-Concentration and Demonstration of Its Utility through Monitoring of Inhibitory Effects of Paraoxon and Carbaryl on AChE. Molecules 2020; 25:E2223. [PMID: 32397331 PMCID: PMC7248789 DOI: 10.3390/molecules25092223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 04/28/2020] [Accepted: 05/06/2020] [Indexed: 12/16/2022] Open
Abstract
We describe a patterned surface-enhanced Raman spectroscopy (SERS) substrate with the ability to pre-concentrate target molecules. A surface-adsorbed nanosphere monolayer can serve two different functions. First, it can be made into a SERS platform when covered by silver. Alternatively, it can be fashioned into a superhydrophobic surface when coated with a hydrophobic molecular species such as decyltrimethoxy silane (DCTMS). Thus, if silver is patterned onto a latter type of substrate, a SERS spot surrounded by a superhydrophobic surface can be prepared. When an aqueous sample is placed on it and allowed to dry, target molecules in the sample become pre-concentrated. We demonstrate the utility of the patterned SERS substrate by evaluating the effects of inhibitors to acetylcholinesterase (AChE). AChE is a popular target for drugs and pesticides because it plays a critical role in nerve signal transduction. We monitored the enzymatic activity of AChE through the SERS spectrum of thiocholine (TC), the end product from acetylthiocholine (ATC). Inhibitory effects of paraoxon and carbaryl on AChE were evaluated from the TC peak intensity. We show that the patterned SERS substrate can reduce both the necessary volumes and concentrations of the enzyme and substrate by a few orders of magnitude in comparison to a non-patterned SERS substrate and the conventional colorimetric method.
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Affiliation(s)
- Umi Yamaguchi
- Graduate School of Life Sciences, Toyo University, Itakura, Gunma 374-0193, Japan;
| | - Maki Ogawa
- Faculty of Life Sciences, Toyo University, Itakura, Gunma 374-0193, Japan;
| | - Hiroyuki Takei
- Faculty of Life Sciences, Toyo University, Itakura, Gunma 374-0193, Japan;
- Bio Nano Electronics Research Centre, Toyo University, Kawagoe, Saitama 350-0815, Japan
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10
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Denet E, Espina-Benitez MB, Pitault I, Pollet T, Blaha D, Bolzinger MA, Rodriguez-Nava V, Briançon S. Metal oxide nanoparticles for the decontamination of toxic chemical and biological compounds. Int J Pharm 2020; 583:119373. [PMID: 32339629 DOI: 10.1016/j.ijpharm.2020.119373] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/22/2020] [Accepted: 04/22/2020] [Indexed: 11/20/2022]
Abstract
For several years, the international context is deeply affected by the use of chemical and biological weapons. The use of CBRN (Chemical Biological Radiological Nuclear) threat agents from military stockpiles or biological civilian industry demonstrate the critical need to improve capabilities of decontamination for civilians and military. Physical decontamination systems that operate only by adsorption and displacement such as Fuller's Earth, have the drawback of not neutralizing hazardous agents, giving place to cross contaminations. Consequently, the development of a formulation based on metal oxide nanoparticles attracts considerable interest, since they offer physicochemical properties that allow them to both adsorb and degrade toxic compounds. Thus, the aim of this study is to found metal oxide nanoparticles with a versatile activity on both chemical and biological toxic agents. Therefore, several metal oxides such as MgO, TiO2, CeO2, ZnO and ZrO2 were characterized and their decontamination kinetics of less-toxic surrogate of VX, paraoxon, were studied in vitro. To determine the antimicrobial activity of these nanoparticles, simulants of biological terrorist threat were used by performing a 3-hours decontamination kinetics. This proof-of-concept study showed that MgO is the only one that exhibits both chemical and antibacterial actions but without sporicidal activity.
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Affiliation(s)
- Elodie Denet
- Université Claude Bernard Lyon 1, Laboratoire d'Ecologie Microbienne (UMR CNRS 5557, INRAe 1418), Villeurbanne, France.
| | - Maria Betzabeth Espina-Benitez
- Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 boulevard du 11 novembre 1918, F-69100 Villeurbanne, France; Université Claude Bernard Lyon 1, Laboratoire de Dermopharmacie et Cosmétologie, Institut des Sciences Pharmaceutiques et Biologique, F-69373 Villeurbanne, France.
| | - Isabelle Pitault
- Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 boulevard du 11 novembre 1918, F-69100 Villeurbanne, France
| | | | - Didier Blaha
- Université Claude Bernard Lyon 1, Laboratoire d'Ecologie Microbienne (UMR CNRS 5557, INRAe 1418), Villeurbanne, France
| | - Marie-Alexandrine Bolzinger
- Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 boulevard du 11 novembre 1918, F-69100 Villeurbanne, France; Université Claude Bernard Lyon 1, Laboratoire de Dermopharmacie et Cosmétologie, Institut des Sciences Pharmaceutiques et Biologique, F-69373 Villeurbanne, France
| | - Veronica Rodriguez-Nava
- Université Claude Bernard Lyon 1, Laboratoire d'Ecologie Microbienne (UMR CNRS 5557, INRAe 1418), Villeurbanne, France
| | - Stéphanie Briançon
- Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 boulevard du 11 novembre 1918, F-69100 Villeurbanne, France; Université Claude Bernard Lyon 1, Laboratoire de Dermopharmacie et Cosmétologie, Institut des Sciences Pharmaceutiques et Biologique, F-69373 Villeurbanne, France.
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Işık M, Beydemir Ş, Demir Y, Durgun M, Türkeş C, Nasır A, Necip A, Akkuş M. Benzenesulfonamide derivatives containing imine and amine groups: Inhibition on human paraoxonase and molecular docking studies. Int J Biol Macromol 2020; 146:1111-1123. [PMID: 31739032 DOI: 10.1016/j.ijbiomac.2019.09.237] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/09/2019] [Accepted: 09/24/2019] [Indexed: 11/19/2022]
Abstract
Sulfonamides known as inhibitors of many metabolic enzymes have been widely used as antimicrobial drugs for a long time. In the present study, we investigated in vitro inhibitory activities of benzenesulfonamide derivatives on human paraoxonase-I (hPON1). For this aim, PON1 was purified from human serum with a specific activity of 2603.57 EU/mg and 8.34% yield using simple chromatographic methods. The various concentrations of early-synthesized sixteen sulfonamide derivatives were tested on the paraoxonase activity. Ki values of compounds were found in the range of 0.28-357.70 µM. Compound H4 had the highest inhibitory activity on hPON1 as competitive. Estimated structure-activity relationship (SAR) for compounds was done based on different substituents and their positions in the compounds. Besides, the molecular docking analysis of compound H4 was performed to understand the binding interactions on the active site of the enzyme. According to these experimental results, compound H4 was a potential inhibitor of PON1.
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Affiliation(s)
- Mesut Işık
- Department of Pharmacy Services, Health Services Vocational School, Harran University, 63300 Şanlıurfa, Turkey
| | - Şükrü Beydemir
- Department of Biochemistry, Faculty of Pharmacy, Anadolu University, 26470 Eskişehir, Turkey.
| | - Yeliz Demir
- Department of Pharmacy Services, Nihat Delibalta Göle Vocational High School, Ardahan University, Ardahan 75700, Turkey
| | - Mustafa Durgun
- Department of Chemistry, Faculty of Arts and Sciences, Harran University, 63290 Şanlıurfa, Turkey
| | - Cüneyt Türkeş
- Department of Biochemistry, Faculty of Pharmacy, Erzincan Binali Yıldırım University, 24100 Erzincan, Turkey
| | - Abdul Nasır
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Adem Necip
- Department of Pharmacy Services, Health Services Vocational School, Harran University, 63300 Şanlıurfa, Turkey
| | - Musa Akkuş
- Department of Chemistry, Faculty of Sciences, Atatürk University, 25240 Erzurum, Turkey
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12
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Cardozo M, de Almeida JSFD, Cavalcante SFDA, Salgado JRS, Gonçalves AS, França TCC, Kuca K, Bizzo HR. Biodegradation of Organophosphorus Compounds Predicted by Enzymatic Process Using Molecular Modelling and Observed in Soil Samples Through Analytical Techniques and Microbiological Analysis: A Comparison. Molecules 2019; 25:molecules25010058. [PMID: 31878010 PMCID: PMC6982719 DOI: 10.3390/molecules25010058] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/15/2019] [Accepted: 12/19/2019] [Indexed: 11/16/2022] Open
Abstract
Organophosphorus compounds (OP) are chemicals widely used as pesticides in different applications such as agriculture and public health (vector control), and some of the highly toxic forms have been used as chemical weapons. After application of OPs in an environment, they persist for a period, suffering a degradation process where the biotic factors are considered the most relevant forms. However, to date, the biodegradation of OP compounds is not well understood. There are a plenty of structure-based biodegradation estimation methods, but none of them consider enzymatic interaction in predicting and better comprehending the differences in the fate of OPs in the environment. It is well known that enzymatic processes are the most relevant processes in biodegradation, and that hydrolysis is the main pathway in the natural elimination of OPs in soil samples. Due to this, we carried out theoretical studies in order to investigate the interactions of these OPs with a chosen enzyme—the phosphotriesterase. This one is characteristic of some soils’ microorganisms, and has been identified as a key player in many biodegradation processes, thanks to its capability for fast hydrolyzing of different OPs. In parallel, we conducted an experiment using native soil in two conditions, sterilized and not sterilized, spiked with specific amounts of two OPs with similar structure—paraoxon-ethyl (PXN) and O-(4-nitrophenyl) O-ethyl methylphosphonate (NEMP). The amount of OP present in the samples and the appearance of characteristic hydrolysis products were periodically monitored for 40 days using analytical techniques. Moreover, the number of microorganisms present was obtained with plate cell count. Our theoretical results were similar to what was achieved in experimental analysis. Parameters calculated by enzymatic hydrolysis were better for PXN than for NEMP. In soil, PXN suffered a faster hydrolysis than NEMP, and the cell count for PXN was higher than for NEMP, highlighting the higher microbiological toxicity of the latter. All these results pointed out that theoretical study can offer a better comprehension of the possible mechanisms involved in real biodegradation processes, showing potential in exploring how biodegradation of OPs relates with enzymatic interactions.
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Affiliation(s)
- Monique Cardozo
- Natural Products Research Institute (IPPN), Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Rio de Janeiro 21941-902, Brazil; (S.F.d.A.C.); (H.R.B.)
- Institute of CBRN Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro 23020-470, Brazil;
- Correspondence: (M.C.); (K.K.); Tel.: +55-021-2410-6305 (M.C.)
| | - Joyce S. F. D. de Almeida
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense (LMACBD) Military Institute of Engineering (IME), Praça General Tibúrcio 80, Rio de Janeiro 22290-270, Brazil; (J.S.F.D.d.A.); (T.C.C.F.)
| | - Samir F. de A. Cavalcante
- Natural Products Research Institute (IPPN), Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Rio de Janeiro 21941-902, Brazil; (S.F.d.A.C.); (H.R.B.)
- Institute of CBRN Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro 23020-470, Brazil;
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic
| | - Jacqueline R. S. Salgado
- Institute of CBRN Defense (IDQBRN), Avenida das Américas 28705, Rio de Janeiro 23020-470, Brazil;
| | - Arlan S. Gonçalves
- Federal Institute of Education, Science and Technology, Avenida Ministro Salgado Filho, 1000, Soteco, Vila Velha 29106-010, Espírito Santo, Brazil;
- Federal University of Espirito Santo- Unit Goiabeiras, Vitória 29075-910, Espírito Santo, Brazil
| | - Tanos C. C. França
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense (LMACBD) Military Institute of Engineering (IME), Praça General Tibúrcio 80, Rio de Janeiro 22290-270, Brazil; (J.S.F.D.d.A.); (T.C.C.F.)
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic
- Correspondence: (M.C.); (K.K.); Tel.: +55-021-2410-6305 (M.C.)
| | - Humberto R. Bizzo
- Natural Products Research Institute (IPPN), Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, Cidade Universitária, Rio de Janeiro 21941-902, Brazil; (S.F.d.A.C.); (H.R.B.)
- Embrapa Agroindústria de Alimentos, Avenida das Américas 29501, Rio de Janeiro 23020-470, Brazil
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Zhang L, Liu Z, Zha S, Liu G, Zhu W, Xie Q, Li Y, Ying Y, Fu Y. Bio-/Nanoimmobilization Platform Based on Bioinspired Fibrin-Bone@Polydopamine-Shell Adhesive Composites for Biosensing. ACS Appl Mater Interfaces 2019; 11:47311-47319. [PMID: 31742992 DOI: 10.1021/acsami.9b15376] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Inspired by blood coagulation and mussel adhesion, we report novel adhesive fibrin-bone@polydopamine (PDA)-shell composite matrix as highly efficient immobilization platform for biomacromolecules and nanomaterials. Fibrin, as a bioglue, and PDA, as a chemical adhesive, are integrated in a one-pot simultaneous polymerization consisting of biopolymerization of fibrinogen and chemical polymerization of dopamine. Fibrin fibers act as adhesive bones to construct scaffold, while PDA coat on the scaffold to form adhesive shell, generating 3D porous composite matrix with unique bone@shell structure. Two types of enzymes (glucose oxidase and acetylcholinesterase) and Au nanoparticles were adopted as respective model biomolecules and nanomaterials to investigate the immobilization capability of the matrix. The bionanocomposites showed high efficiency in capturing nanoparticles and enzymes, as well as significant mass-transfer and biocatalysis efficiencies. Therefore, the bionanocomposites exhibited significant potential in biosensing of glucose and paraoxon with limits of detection down to 5.2 μM and 4 ppt, respectively. The biological-chemical-combined polymerization strategy and composite platform with high immobilization capacity and mass-transfer efficiency open up a novel way for the preparation of high-performance bionanocomposites for various applications, in particular, biosensing.
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Affiliation(s)
| | - Ziyu Liu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) , Hunan Normal University , Changsha 410081 , China
| | | | | | | | - Qingji Xie
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) , Hunan Normal University , Changsha 410081 , China
| | - Yanbin Li
- Department of Biological and Agricultural Engineering , University of Arkansas , Fayetteville , Arkansas 72701 , United States
| | - Yibin Ying
- Zhejiang A&F University , Hangzhou , Zhejiang 311300 , China
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Wu Y, Jiao L, Xu W, Gu W, Zhu C, Du D, Lin Y. Polydopamine-Capped Bimetallic AuPt Hydrogels Enable Robust Biosensor for Organophosphorus Pesticide Detection. Small 2019; 15:e1900632. [PMID: 30938485 DOI: 10.1002/smll.201900632] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/14/2019] [Indexed: 05/28/2023]
Abstract
Noble metal hydrogels/aerogels with macroscopic nanoassemblies characterized by ultralow density, profuse continuous porosity, and extremely large surface area have gained abundant interest due to not only their tunable physicochemical properties, but also promising applications in catalysis and sensing. Coupling the increased reaction temperature with dopamine-induced effect, herein, a one-step synthetic approach with accelerated gelation kinetics is reported for the synthesis of polydopamine-capped bimetallic AuPt hydrogels. 3D porous nanowire networks with surface functionalization of polydopamine make them a promising biocompatible microenvironment for immobilizing acetylcholinesterase (AChE) and constructing enzyme-based biosensors for sensitive detection of organophosphorus compounds. Taking advantage of their favorable structure and composition, the optimized product exhibits superior electrochemical activity toward thiocholine produced by AChE-catalyzed hydrolysis of acetylthiocholine. Based on the inhibition of organophosphorus pesticide on the enzymatic activity of AChE, the inhibition mode for the detection of paraoxon-ethyl is established, displaying linear regions over the range of 0.5-1000 ng L-1 with a low detection limit of 0.185 ng L-1 .
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Affiliation(s)
- Yu Wu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Lei Jiao
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Weiqing Xu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Wenling Gu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Chengzhou Zhu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China
| | - Dan Du
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, 99164, USA
| | - Yuehe Lin
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA, 99164, USA
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15
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Moon Y, Jafry AT, Bang Kang S, Young Seo J, Baek KY, Kim EJ, Pan JG, Choi JY, Kim HJ, Han Lee K, Jeong K, Bae SW, Shin S, Lee J, Lee Y. Organophosphorus hydrolase-poly-β-cyclodextrin as a stable self-decontaminating bio-catalytic material for sorption and degradation of organophosphate pesticide. J Hazard Mater 2019; 365:261-269. [PMID: 30447633 DOI: 10.1016/j.jhazmat.2018.10.094] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 10/05/2018] [Accepted: 10/31/2018] [Indexed: 05/25/2023]
Abstract
A region suffering from an attack of a nerve agent requires not only a highly sorptive material but also a fast-acting catalyst to decontaminate the lethal chemical present. The product should be capable of high sorptive capacity, selectivity and quick response time to neutralize the long lasting harmful effects of nerve agents. Herein, we have utilized organophosphorus hydrolase (OPH) as a non-toxic bio-catalytic material held in with the supporting matrix of poly-β-cyclodextrin (PCD) as a novel sorptive reinforced self-decontaminating material against organophosphate intoxication. OPH coated PCD (OPH-PCD) will not only be providing support for holding enzyme but also would be adsorbing methyl paraoxon (MPO) used as a simulant, in a host-guest inclusion complex formation. Sorption trend for PCD revealed preference towards the more hydrophobic MPO against para-nitrophenol (pNP). The results show sorption capacity of 1.26 mg/g of 100 μM MPO with PCD which was 1.7 times higher compared to pNP. The reaction rate with immobilized OPH-PCD was found to be 23% less compared to free enzyme. With the help of OPH-PCD, continuous hydrolysis (100%) of MPO into pNP was observed for a period of 24 h through packed bed reactor with good reproducibility and stability of enzyme. The long-term stability also confirmed its stable nature for the investigation period of 4 days where it maintained activity. Combined with its fast and reactive nature, the resulting self-decontaminating regenerating material provides a promising strategy for the neutralization of nerve agents and preserving the environment.
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Affiliation(s)
- Youngkwang Moon
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Ali Turab Jafry
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Soon Bang Kang
- Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Jin Young Seo
- Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Kyung-Youl Baek
- Korea Institute of Science and Technology, Seoul, Republic of Korea
| | | | | | | | - Hyun-Ji Kim
- Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Kang Han Lee
- Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Keunhong Jeong
- Department of Chemistry and Nuclear & WMD Protection Research Center, Korea Military Academy, Seoul, Republic of Korea
| | - Se Won Bae
- Korea Institute of Industrial Technology, Cheonan, Republic of Korea
| | - Seunghan Shin
- Korea Institute of Industrial Technology, Cheonan, Republic of Korea
| | - Jinkee Lee
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do, 16419, Republic of Korea.
| | - Yongwoo Lee
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do, 16419, Republic of Korea.
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16
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de Paula RL, de Almeida JSFD, Cavalcante SFA, Gonçalves AS, Simas ABC, Franca TCC, Valis M, Kuca K, Nepovimova E, Granjeiro JM. Molecular Modeling and In Vitro Studies of a Neutral Oxime as a Potential Reactivator for Acetylcholinesterase Inhibited by Paraoxon. Molecules 2018; 23:E2954. [PMID: 30424582 PMCID: PMC6278417 DOI: 10.3390/molecules23112954] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 11/16/2022] Open
Abstract
The present work aimed to compare the small, neutral and monoaromatic oxime, isatin-3-oxime (isatin-O), to the commercial ones, pralidoxime (2-PAM) and obidoxime, in a search for a new potential reactivator for acetylcholinesterase (AChE) inhibited by the pesticide paraoxon (AChE/POX) as well as a novel potential scaffold for further synthetic modifications. The multicriteria decision methods (MCDM) allowed the identification of the best docking poses of those molecules inside AChE/POX for further molecular dynamic (MD) studies, while Ellman's modified method enabled in vitro inhibition and reactivation assays. In corroboration with the theoretical studies, our experimental results showed that isatin-O have a reactivation potential capable of overcoming 2-PAM at the initial moments of the assay. Despite not achieving better results than obidoxime, this molecule is promising for being an active neutral oxime with capacity of crossing the blood⁻brain barrier (BBB), to reactivate AChE/POX inside the central and peripheral nervous systems. Moreover, the fact that isatin-O can also act as anticonvulsant makes this molecule a possible multipotent reactivator. Besides, the MCDM method showed to be an accurate method for the selection of the best docking poses generated in the docking studies.
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Affiliation(s)
- Reuel L de Paula
- National Institute of Metrology, Quality and Technology (INMETRO), Avenida Nossa Senhora das Graças 50, Duque de Caxias 25250-020, Brazil.
- IDQBRN (Brazilian Army CBRN Defense Institute), Avenida das Américas 28705, Rio de Janeiro 23020-470, Brazil.
| | - Joyce S F D de Almeida
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Praça General Tibúrcio 80, Rio de Janeiro 22290-270, Brazil.
| | - Samir F A Cavalcante
- IDQBRN (Brazilian Army CBRN Defense Institute), Avenida das Américas 28705, Rio de Janeiro 23020-470, Brazil.
- Walter Mors Institute of Research on Natural Products, Federal University of Rio de Janeiro (UFRJ), CCS Bloco H Cidade Universitária, Rio de Janeiro 21941-902, Brazil.
| | - Arlan S Gonçalves
- Federal Institute of Education, Science and Technology, Avenida Ministro Salgado Filho S/N, Vila Velha 29106-010, Brazil.
| | - Alessandro B C Simas
- Walter Mors Institute of Research on Natural Products, Federal University of Rio de Janeiro (UFRJ), CCS Bloco H Cidade Universitária, Rio de Janeiro 21941-902, Brazil.
| | - Tanos C C Franca
- Laboratory of Molecular Modeling Applied to Chemical and Biological Defense, Military Institute of Engineering, Praça General Tibúrcio 80, Rio de Janeiro 22290-270, Brazil.
- Center for Basic and Applied Research, Faculty of Informatics and Management, University of Hradec Králové, Rokitanskeho 62, 50003 Hradec Králové, Czech Republic.
| | - Martin Valis
- Department of Neurology, Charles University in Prague, Faculty of Medicine in Hradec Králové and University Hospital, Simkova 870, 50003 Hradec Králové, Czech Republic.
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Rokitanskeho 62, 50003 Hradec Králové, Czech Republic.
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Králové, Rokitanskeho 62, 50003 Hradec Králové, Czech Republic.
| | - José M Granjeiro
- National Institute of Metrology, Quality and Technology (INMETRO), Avenida Nossa Senhora das Graças 50, Duque de Caxias 25250-020, Brazil.
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Ma X, Zhang L, Xia M, Zhang X, Zhang Y. Catalytic degradation of organophosphorous nerve agent simulants by polymer beads@graphene oxide with organophosphorus hydrolase-like activity based on rational design of functional bimetallic nuclear ligand. J Hazard Mater 2018; 355:65-73. [PMID: 29775879 DOI: 10.1016/j.jhazmat.2018.04.084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/22/2018] [Accepted: 04/29/2018] [Indexed: 06/08/2023]
Abstract
The degradation of organophosphorous nerve agents is of primary concern due to the severe toxicity of these agents. Based on the active center of organophosphorus hydrolase (OPH), a bimetallic nuclear ligand, (5-vinyl-1,3-phenylene)bis(di(1H-imidazol-2-yl) methanol) (VPIM), was designed and synthesized, which contains four imidazole groups to mimic the four histidines at OPH active center. By grafting VPIM on graphene oxide (GO) surface via polymerization, the VPIM-polymer beads@GO was produced. The obtained OPH mimics has an impressive activity in dephosphorylation reactions (turnover frequency (TOF) towards paraoxon: 2.3 s-1). The synergistic catalytic effect of the bimetallic Zn2+ nuclear center and carboxyl groups on surface of GO possibly contributes to the high hydrolysis on organophosphate substrate. Thus, a biomimetic catalyst for efficient degradation of some organophosphorous nerve agent simulants, such as paraoxon and chlorpyrifos, was prepared by constructing catalytic active sites. The proposed mechanism and general synthetic strategy open new avenues for the engineering of functional GOs for biomimetic catalysts.
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Affiliation(s)
- Xuejuan Ma
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Changan West Road 620, 710119, Xi'an, China; Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Changan West Road 620, 710119, Xi'an, China
| | - Lin Zhang
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Changan West Road 620, 710119, Xi'an, China; Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Changan West Road 620, 710119, Xi'an, China
| | - Mengfan Xia
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Changan West Road 620, 710119, Xi'an, China; Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Changan West Road 620, 710119, Xi'an, China
| | - Xiaohong Zhang
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Changan West Road 620, 710119, Xi'an, China; Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Changan West Road 620, 710119, Xi'an, China
| | - Yaodong Zhang
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Changan West Road 620, 710119, Xi'an, China; Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Changan West Road 620, 710119, Xi'an, China.
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Salerno A, Pitault I, Devers T, Pelletier J, Briançon S. Model-based optimization of parameters for degradation reaction of an organophosphorus pesticide, paraoxon, using CeO 2 nanoparticles in water media. Environ Toxicol Pharmacol 2017; 53:18-28. [PMID: 28499266 DOI: 10.1016/j.etap.2017.04.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/24/2017] [Accepted: 04/29/2017] [Indexed: 06/07/2023]
Abstract
Degradation and body surface decontamination is vital to prevent the skin penetration of paraoxon (POX), an organophosphorus pesticide, and victims poisoning. CeO2 demonstrated a good efficacy for the degradation of POX. The aim of the study was to develop a model which includes the impact of weight of CeO2, POX and diluent volumes on the degradation kinetics. The modelling was realized with rapid and simple experiments carried out in tubes, in aqueous diluent which contained ions in order to be in accordance with in vitro skin decontamination conditions. CeO2 had degraded from 5% (in case of 7.5mmol of POX per gram of CeO2) to 100% (0.002mmol of POX per gram of CeO2) of POX. Different kinetic models were tested. Using the particle aggregation kinetic model, the simulated and experimental data were in a good accordance. It highlighted the importance of particles aggregation due to salts and consistency of the mix on the degradation efficiency of CeO2. The model worked also really well to predict the degradation efficiency of CeO2 powders during in vitro skin experiments. However, it did not correctly forecast with an aqueous decontaminant, containing CeO2.
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Affiliation(s)
- Alicia Salerno
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEP UMR 5007, 43 Boulevard du 11 Novembre 1918, F-69100, Villeurbanne, France; Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire de Dermopharmacie et Cosmétologie, Institut des Sciences Pharmaceutiques et Biologique, F-69373, Lyon, France
| | - Isabelle Pitault
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEP UMR 5007, 43 Boulevard du 11 Novembre 1918, F-69100, Villeurbanne, France.
| | - Thierry Devers
- Interfaces Confinement Matériaux et Nanostructures, IUT de Chartres, Université d'Orléans, F-28000, Chartres, France
| | - Jocelyne Pelletier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEP UMR 5007, 43 Boulevard du 11 Novembre 1918, F-69100, Villeurbanne, France; Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire de Dermopharmacie et Cosmétologie, Institut des Sciences Pharmaceutiques et Biologique, F-69373, Lyon, France
| | - Stéphanie Briançon
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEP UMR 5007, 43 Boulevard du 11 Novembre 1918, F-69100, Villeurbanne, France; Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire de Dermopharmacie et Cosmétologie, Institut des Sciences Pharmaceutiques et Biologique, F-69373, Lyon, France
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Gençer N, Yavuz E. An alternative purification method for human serum paraoxonase 1 and its interaction with methidathion. Arch Physiol Biochem 2017; 123:159-164. [PMID: 28276711 DOI: 10.1080/13813455.2017.1279632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In this study, an alternative purification method for human Paraoxonase 1 (hPON1) enzyme was developed using two-step procedures, namely ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-aminoanthracene hydrophobic interaction chromatography. SDS-polyacrylamide gel electrophoresis of the enzyme indicates a single band with an apparent MW of 43 kDa. The enzyme was purified 674-fold with a yield of 16%. Furthermore, we examined the in vitro effect of methidathion on the enzyme activity to understand the better inhibitory properties of the compound. Methidathion is a highly toxic insecticide used to control a broad spectrum of agricultural insect and mite pests. IC50 value was found to be 0.130 mM for the pesticide. Methidathion showed a competitive inhibition with Ki of 0.119 mM for paraoxon.
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Affiliation(s)
- Nahit Gençer
- a Department of Chemistry , Faculty of Art and Science, Balikesir University , Balikesir , Turkey
| | - Emre Yavuz
- a Department of Chemistry , Faculty of Art and Science, Balikesir University , Balikesir , Turkey
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Abstract
Understanding the molecular interactions between small molecules and double-stranded DNA has important implications on the design and development of DNA and DNA-protein nanomaterials. Such materials can be assembled into a vast array of 1-, 2-, and 3D structures that contain a range of chemical and physical features where small molecules can bind via intercalation, groove binding, and electrostatics. In this work, we use a series of simulation-guided binding assays and spectroscopy techniques to investigate the binding of selected organophosphtates, methyl parathion, paraoxon, their common enzyme hydrolysis product p-nitrophenol, and double-stranded DNA fragments and DNA DX tiles, a basic building block of DNA-based materials. Docking simulations suggested that the binding strength of each compound was DNA sequence-dependent, with dissociation constants in the micromolar range. Microscale thermophoresis and fluorescence binding assays confirmed sequence-dependent binding and that paraoxon bound to DNA with Kd's between ∼10 and 300 μM, while methyl parathion bound with Kd's between ∼10 and 100 μM. p-Nitrophenol also bound to DNA but with affinities up to 650 μM. Changes in biding affinity were due to changes in binding mode as revealed by circular dichroism spectroscopy. Based on these results, two DNA DX tiles were constructed and analyzed, revealing tighter binding to the studied compounds. Taken together, the results presented here add to our fundamental understanding of the molecular interactions of these compounds with biological materials and opens new possibilities in DNA-based sensors, DNA-based matrices for organophosphate extraction, and enzyme-DNA technologies for organophosphate hydrolysis.
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Affiliation(s)
- Yingning Gao
- Department of Chemical and Environmental Engineering, University of California , Riverside, California 92521, United States
| | - Samson Or
- Department of Chemical and Environmental Engineering, University of California , Riverside, California 92521, United States
| | - Aaron Toop
- Department of Chemical and Environmental Engineering, University of California , Riverside, California 92521, United States
| | - Ian Wheeldon
- Department of Chemical and Environmental Engineering, University of California , Riverside, California 92521, United States
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Breger JC, Ancona MG, Walper SA, Oh E, Susumu K, Stewart MH, Deschamps JR, Medintz IL. Understanding How Nanoparticle Attachment Enhances Phosphotriesterase Kinetic Efficiency. ACS Nano 2015; 9:8491-503. [PMID: 26230391 DOI: 10.1021/acsnano.5b03459] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
As a specific example of the enhancement of enzymatic activity that can be induced by nanoparticles, we investigate the hydrolysis of the organophosphate paraoxon by phosphotriesterase (PTE) when the latter is displayed on semiconductor quantum dots (QDs). PTE conjugation to QDs underwent extensive characterization including structural simulations, electrophoretic mobility shift assays, and dynamic light scattering to confirm orientational and ratiometric control over enzyme display which appears to be necessary for enhancement. PTE hydrolytic activity was then examined when attached to ca. 4 and 9 nm diameter QDs in comparison to controls of freely diffusing enzyme alone. The results confirm that the activity of the QD conjugates significantly exceeded that of freely diffusing PTE in both initial rate (∼4-fold) and enzymatic efficiency (∼2-fold). To probe kinetic acceleration, various modified assays including those with increased temperature, presence of a competitive inhibitor, and increased viscosity were undertaken to measure the activation energy and dissociation rates. Cumulatively, the data indicate that the higher activity is due to an acceleration in enzyme-product dissociation that is presumably driven by the markedly different microenvironment of the PTE-QD bioconjugate's hydration layer. This report highlights how a specific change in an enzymatic mechanism can be both identified and directly linked to its enhanced activity when displayed on a nanoparticle. Moreover, the generality of the mechanism suggests that it could well be responsible for other examples of nanoparticle-enhanced catalysis.
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Affiliation(s)
- Joyce C Breger
- American Society for Engineering Education , Washington, DC 20036, United States
| | | | | | - Eunkeu Oh
- Sotera Defense Solutions, Inc. 7230 Lee DeForest Drive, Columbia, Maryland 21046, United States
| | - Kimihiro Susumu
- Sotera Defense Solutions, Inc. 7230 Lee DeForest Drive, Columbia, Maryland 21046, United States
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Liebes-Peer Y, Rapaport H, Ashkenasy N. Amplification of single molecule translocation signal using β-strand peptide functionalized nanopores. ACS Nano 2014; 8:6822-6832. [PMID: 24949890 DOI: 10.1021/nn501331u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Changes in ionic current flowing through nanopores due to binding or translocation of single biopolymer molecules enable their detection and characterization. It is, however, much more challenging to detect small molecules due to their rapid and small signal signature. Here we demonstrate the use of de novo designed peptides for functionalization of nanopores that enable the detection of a small analytes at the single molecule level. The detection relies on cooperative peptide conformational change that is induced by the binding of the small molecule to a receptor domain on the peptide. This change results in alteration of the nanopore effective diameter and hence induces current perturbation signal. On the basis of this approach, we demonstrate here the detection of diethyl 4-nitrophenyl phosphate (paraoxon), a poisonous organophosphate molecule. Paraoxon binding is induced by the incorporation of the catalytic triad of acetylcholine esterase in the hydrophilic domain of a short amphiphilic peptide and promotes β-sheet assembly of the peptide both in solution and for peptide molecules immobilized on solid surfaces. Nanopores coated with this peptide allowed the detection of paraoxon at the single molecule level revealing two binding arrangements. This unique approach, hence, provides the ability to study interactions of small molecules with the corresponding engineered receptors at the single molecule level. Furthermore, the suggested versatile platform may be used for the development of highly sensitive small analytes sensors.
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Affiliation(s)
- Yael Liebes-Peer
- Department of Biotechnology Engineering, ‡Department of Materials Engineering, and §The Ilze Katz Institute for Nanoscale Technology, Ben-Gurion University of the Negev , P.O. Box 653, Beer-Sheva 84105, Israel
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McDaniel CY, Dail MB, Wills RW, Chambers HW, Chambers JE. Paraoxonase 1 polymorphisms within a Mississippi USA population as possible biomarkers of enzyme activities associated with disease susceptibility. Biochem Genet 2014; 52:509-23. [PMID: 25027835 DOI: 10.1007/s10528-014-9663-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/23/2014] [Indexed: 01/22/2023]
Abstract
Paraoxonase (PON1) hydrolyzes paraoxon (PO) and diazoxon (DZO), active metabolites of insecticides parathion and diazinon. The PON1 gene has single nucleotide polymorphisms (SNPs) including a codon 192 arginine (R) to glutamine (Q) and methionine (M) to leucine (L) at codon 55. Hydrolysis of PO (POase), DZO (DZOase), dihydrocoumarin (lactonase), and phenyl acetate (arylesterase) were evaluated for associations with race, gender, age, and PON1 55/192 SNP genotypes. Variables were analyzed both individually and in combination. QQ individuals had higher lactonase (p < 0.001) than RR individuals. This might partially explain why predominantly RR African Americans have higher rates of coronary disease than predominantly QQ Caucasians. Significant (p < 0.001) differences in arylesterase were seen among genotypes with QQ and MM lowest whereas RR and LL were highest. This opposes the prevailing belief that arylesterase is unaffected by genotype and suggests that this activity cannot be used to quantify PON1 protein.
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Affiliation(s)
- Chiquita Y McDaniel
- Basic Sciences Department and Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, P.O. Box 6100, 240 Wise Center Drive, Mississippi State, MS, 39762-6100, USA
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Soni SD, Bhonsle JB, Garcia GE. Biophysical aspects of cyclodextrin interaction with paraoxon. Magn Reson Chem 2014; 52:111-114. [PMID: 24357355 DOI: 10.1002/mrc.4036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 11/14/2013] [Accepted: 11/18/2013] [Indexed: 06/03/2023]
Abstract
Cyclodextrins are torus-shaped polymers of glucose that can bind organophosphorous compounds such as nerve agents and pesticides. We demonstrate here that cyclodextrin can bind up to two paraoxon molecules with a K(av) of 6775 M(-1). Molecular modeling shows that the paraoxon appears to bind in polar opposite orientation and have an average binding energy of -89 Kcals/mol. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Sunil-Datta Soni
- Physiology and Immunology, USAMRICD, Aberdeen Proving Ground, MD, USA
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Zhan D, Zhou Z, Guan S, Han W. The effect of conformational variability of phosphotriesterase upon N-acyl-L-homoserine lactone and paraoxon binding: insights from molecular dynamics studies. Molecules 2013; 18:15501-18. [PMID: 24352010 PMCID: PMC6269825 DOI: 10.3390/molecules181215501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/03/2013] [Accepted: 12/06/2013] [Indexed: 11/16/2022] Open
Abstract
The organophosphorous hydrolase (PTE) from Brevundimonas diminuta is capable of degrading extremely toxic organophosphorous compounds with a high catalytic turnover and broad substrate specificity. Although the natural substrate for PTE is unknown, its loop remodeling (loop 7-2/H254R) led to the emergence of a homoserine lactonase (HSL) activity that is undetectable in PTE (kcat/km values of up to 2 × 10(4)), with only a minor decrease in PTE paraoxonase activity. In this study, homology modeling and molecular dynamics simulations have been undertaken seeking to explain the reason for the substrate specificity for the wild-type and the loop 7-2/H254R variant. The cavity volume estimated results showed that the active pocket of the variant was almost two fold larger than that of the wild-type (WT) enzyme. pKa calculations for the enzyme (the WT and the variant) showed a significant pKa shift from WT standard values (ΔpKa = 3.5 units) for the His254 residue (in the Arg254 variant). Molecular dynamics simulations indicated that the displacement of loops 6 and 7 over the active site in loop 7-2/H254R variant is useful for N-acyl-L-homoserine lactone (C4-HSL) with a large aliphatic chain to site in the channels easily. Thence the expanding of the active pocket is beneficial to C4-HSL binding and has a little effect on paraoxon binding. Our results provide a new theoretical contribution of loop remodeling to the rapid divergence of new enzyme functions.
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Affiliation(s)
- Dongling Zhan
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, Changchun 130023, China; E-Mail:
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China
| | - Zhenhuan Zhou
- Jilin Provincial Research Institute of Population and Life sciences, Changchun 130041, China; E-Mail:
| | - Shanshan Guan
- State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130023, China; E-Mail:
| | - Weiwei Han
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, Changchun 130023, China; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +86-431-8515-5218
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Yaakobi K, Liebes-Peer Y, Kushmaro A, Rapaport H. Designed amphiphilic β-sheet peptides as templates for paraoxon adsorption and detection. Langmuir 2013; 29:6840-6848. [PMID: 23631528 DOI: 10.1021/la401280e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Amphiphilic peptides were designed to fold into a β-sheet monolayer structure while presenting the catalytic triad residues of the enzyme, acetylcholinesterase (Glu, His, and Ser), to a solution containing the organophosphate, paraoxon. Three peptides, in which the catalytic triad residues were arranged in different orders along the strand, were generated to reveal potential differences in interactions with paraoxon as a function of the order of these amino acids. One additional peptide with amino acids introduced in random order was studied to highlight the contribution of the β-sheet secondary structure to any interactions with paraoxon. Langmuir isotherms, Brewster angle microscope at interfaces, and circular dichroism measurements in bulk showed that both the β-sheet conformation and the order of the amino acids along the strand influenced the interactions of paraoxon with the peptides. Compression isotherm curves as well as Brewster angle microscopy images provided evidence for enhanced adsorption of the paraoxon to the monolayers of peptides, which present neighboring Glu and Ser residues along the hydrophilic face of the β-strand. Circular dichroism revealed that the peptide most sensitive to interactions with paraoxon was that with the triad residues in the order Glu, Ser, and His, which appears to be appropriate for supporting a catalytic mechanism similar to that in the acetylcholinesterase enzyme. These rationally designed peptides may be further used for the development of technologies for organophosphate adsorption and detection.
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Affiliation(s)
- Keren Yaakobi
- Unit of Environmental Engineering, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
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Liu G, Song D, Chen F. Towards the fabrication of a label-free amperometric immunosensor using SWNTs for direct detection of paraoxon. Talanta 2012; 104:103-8. [PMID: 23597895 DOI: 10.1016/j.talanta.2012.11.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 11/09/2012] [Accepted: 11/17/2012] [Indexed: 11/30/2022]
Abstract
A label-free immunosensor based on SWNTs modified GC electrodes has been developed for the direct detection of paraoxon. Based on aryldiazonium salt chemistry, forest of SWNTs can be vertically aligned on mixed monolayers of aryldiazonium salt modified GC electrodes by C-C bonding, which provides an interface showing efficient electron transfer between biomolecules. PEG molecules were introduced to the interface to resist non-specific protein adsorption. Ferrocenedimethylamine (FDMA) was subsequently attached to the ends of SWNTs through the amide bonding followed by the attachment of epitope i.e., paraoxon hapten to which a paraoxon antibody would bind. This immunosensor shows good selectivity and high specificity to paraoxon, and is functional for the detection of paraoxon in both laboratory and field by a displacement assay. There is a linear relationship between electrochemical signal of FDMA and the concentration of paraoxon over the range of 2-2500 ppb with a lowest detected limit of 2 ppb in 0.1 M phosphate buffer at pH 7.0. The SWNTs based amperometric immunosensor provides an opportunity to develop the sensing system for on-site sensitive detection of a spectrum of insecticides.
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Affiliation(s)
- Guozhen Liu
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
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Chi W, Shi H, Shi W, Guo Y, Guo T. 4-nitrophenol surface molecularly imprinted polymers based on multiwalled carbon nanotubes for the elimination of paraoxon pollution. J Hazard Mater 2012; 227-228:243-9. [PMID: 22652321 DOI: 10.1016/j.jhazmat.2012.05.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 05/11/2012] [Accepted: 05/11/2012] [Indexed: 05/25/2023]
Abstract
Molecularly imprinted polymers were grafted on the surface of multiwalled carbon nanotubes (MWCNT) using the hydrolysis product of paraoxon 4-nitrophenol as template, 4-vinyl pyridine (4-VPy) as the functional monomer and divinylbenzen (DVB) as the crosslinker. The binding experiments of 4-nitrophenol indicated that the MWCNT based molecularly imprinted polymers (MWCNT-MIP) have much higher adsorption ability than the MWCNT based non-imprinted polymers (MWCNT-NIP). At the same time we found that the adsorption of 4-nitrophenol can help to increase the hydrolytic rate of paraoxon, which indicates that there is an obvious catalyzing effect on the hydrolysis of paraoxon for this kind of materials. Furthermore, the 4-nitrophenol left in the paraoxon hydrolysis medium is only 0.01056 mM for MWCNT-MIP in the catalytic experiment of paraoxon we made (the initial concentration of paraoxon is 0.5 mM and MWCNT-MIP is 4 mg), which indicates that this kind of MWCNT based imprinted polymers can not only catalyze the hydrolysis of paraoxon but also eliminate the poisonous organism product 4-nitrophenol.
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Affiliation(s)
- Wenhao Chi
- Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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Zheng N, Fung EN, Buzescu A, Arnold ME, Zeng J. Esterase inhibitors as ester-containing drug stabilizers and their hydrolytic products: potential contributors to the matrix effects on bioanalysis by liquid chromatography/tandem mass spectrometry. Rapid Commun Mass Spectrom 2012; 26:1291-1304. [PMID: 22555922 DOI: 10.1002/rcm.6230] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
RATIONALE Esterase inhibitors are widely used to stabilize ester-containing drugs in biological matrices for quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) assays. These co-existing inhibitors could cause matrix effects on bioanalysis and jeopardize the assay performance. We therefore developed an LC/MS/MS methodology to monitor the fate of inhibitors and evaluate their matrix effects, which is described in this study. METHODS Human plasma containing 20 mM of diisopropylfluorophosphate (DFP), paraoxon, eserine, phenylmethylsulfonyl fluoride (PMSF) or 2-thenoyltrifluoroacetone (TTFA) was extracted by liquid-liquid extraction (LLE) and analyzed by an LC/MS/MS assay for BMS-068645 (a model drug) with additional pre-optimized selected reaction monitoring (SRM) transitions using positive/negative electrospray ionization (ESI) mode for each inhibitor. Hydrolytic products were characterized by product ion or neutral loss scan LC/MS/MS analysis. The matrix effect contribution from each inhibitor was evaluated by post-column infusion of BMS-068645. RESULTS In the extracted samples by LLE, SRM chromatograms revealed the presence of paraoxon, eserine and TTFA with peak intensity of >2.50E08. Three DFP hydrolytic products, diisopropyl phosphate (DP), triisopropyl phosphate (TP) and DP dimer, and one PMSF hydrolytic product, phenymethanesulfonic acid (PMSA), were identified in the extracted samples. In post-column infusion profiles, ion suppression or enhancement was observed in the retention time regions of eserine (~10% suppression), paraoxon (~70% enhancement) and DP dimer (~20% suppression). CONCLUSIONS The SRM transitions described here make it possible to directly monitor the inhibitors and their hydrolytic products. In combination with post-column infusion, this methodology provides a powerful tool to routinely monitor the matrix effects-causing inhibitors, so that their matrix effects on the bioanalysis can be evaluated and minimized.
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Affiliation(s)
- Naiyu Zheng
- Bioanalytical Sciences, Bristol-Myers Squibb Research & Development, Princeton, NJ 08543, USA
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Pohanka M, Hrabinova M, Kuca K, Simonato JP. Assessment of acetylcholinesterase activity using indoxylacetate and comparison with the standard Ellman's method. Int J Mol Sci 2011; 12:2631-40. [PMID: 21731462 PMCID: PMC3127138 DOI: 10.3390/ijms12042631] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 03/01/2011] [Accepted: 03/29/2011] [Indexed: 01/18/2023] Open
Abstract
Assay of acetylcholinesterase (AChE) activity plays an important role in diagnostic, detection of pesticides and nerve agents, in vitro characterization of toxins and drugs including potential treatments for Alzheimer’s disease. These experiments were done in order to determine whether indoxylacetate could be an adequate chromogenic reactant for AChE assay evaluation. Moreover, the results were compared to the standard Ellman’s method. We calculated Michaelis constant Km (2.06 × 10−4 mol/L for acetylthiocholine and 3.21 × 10−3 mol/L for indoxylacetate) maximum reaction velocity Vmax (4.97 × 10−7 kat for acetylcholine and 7.71 × 10−8 kat for indoxylacetate) for electric eel AChE. In a second part, inhibition values were plotted for paraoxon, and reactivation efficacy was measured for some standard oxime reactivators: obidoxime, pralidoxime (2-PAM) and HI-6. Though indoxylacetate is split with lower turnover rate, this compound appears as a very attractive reactant since it does not show any chemical reactivity with oxime antidots and thiol used for the Ellman’s method. Thus it can be advantageously used for accurate measurement of AChE activity. Suitability of assay for butyrylcholinesterase activity assessment is also discussed.
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Affiliation(s)
- Miroslav Pohanka
- Faculty of Military Health Sciences, University of Defense, Trebesska 1575, 50001 Hradec Kralove, Czech Republic
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +420-973-253-091; Fax: +420-973-253-091
| | - Martina Hrabinova
- Faculty of Military Health Sciences, University of Defense, Trebesska 1575, 50001 Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Faculty of Military Health Sciences, University of Defense, Trebesska 1575, 50001 Hradec Kralove, Czech Republic
| | - Jean-Pierre Simonato
- CEA-Grenoble, LITEN/DTNM/LCRE, 17 rue des Martyrs, 38000 Grenoble, France; E-Mail:
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Bharate SB, Prins JM, George KM, Thompson CM. Thionate versus Oxon: comparison of stability, uptake, and cell toxicity of ((14)CH(3)O)(2)-labeled methyl parathion and methyl paraoxon with SH-SY5Y cells. J Agric Food Chem 2010; 58:8460-8466. [PMID: 20590114 PMCID: PMC2932872 DOI: 10.1021/jf100976v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The stability, hydrolysis, and uptake of the organophosphates methyl parathion and methyl paraoxon were investigated in SH-SY5Y cells. The stabilities of ((14)CH(3)O)(2)-methyl parathion ((14)C-MPS) and ((14)CH(3)O)(2)-methyl paraoxon ((14)C-MPO) at 1 microM in culture media had similar half-lives of 91.7 and 101.9 h, respectively. However, 100 microM MPO caused >95% cytotoxicity at 24 h, whereas 100 microM MPS caused 4-5% cytotoxicity at 24 h ( approximately 60% cytotoxicity at 48 h). Greater radioactivity was detected inside cells treated with MPO as compared to MPS, although >80% of the total MPO uptake was primarily dimethyl phosphate (DMP). Maximum uptake was reached after 48 h of (14)C-MPS or (14)C-MPO exposure with total uptakes of 1.19 and 1.76 nM/10(6) cells for MPS and MPO, respectively. The amounts of MPS and MPO detected in the cytosol after 48 h of exposure time were 0.54 and 0.37 nM/10(6) cells, respectively.
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Affiliation(s)
- Sandip B. Bharate
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula MT 59812
| | - John M. Prins
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula MT 59812
| | - Kathleen M. George
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula MT 59812
| | - Charles M. Thompson
- The Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula MT 59812
- ATERIS Technologies LLC, 901 N Orange Street, Missoula MT 59802
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Jha N, Ramaprabhu S. Carbon nanotube-polymer based nanocomposite as electrode material for the detection of paraoxon. J Nanosci Nanotechnol 2010; 10:2798-2802. [PMID: 20355504 DOI: 10.1166/jnn.2010.1425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Biosensor based on the inhibition of enzymes has been used for the detection of organophosphorous compounds wherein amperometic method has been employed. Carbon nanotubes (CNT) has been grown over YNi3 alloy hydrides and purified for further use. The high surface area and the acidic sites created during the purification of CNT with oxidizing acids have been exploited for the adsorption and entrapment of the enzyme acetylcholine esterase. In the present work, conducting polymer polypyrrole has been uniformly coated over the CNT surface using chemical oxidative technique. The nanocomposite was characterized by scanning electron microscopy (SEM) and High resolution transmission electron microscopy (HRTEM). In the present report high catalytic activity of CNT towards the electroxidation of thiocholine has been utilized for the detection of organophosphorous compound paraoxon. Developed biosensor uses the principal of acetylcholinesterase inhibition by nerve agent and hence reduction in oxidation current of thiocholine for the detection of paraoxon. Synthesized PPY-MWNT nanocomposite has been used for the electrode preparation over GC electrode. Due to high porosity of polymer and high electrical conductivity of CNT, a detection level of 3 nM paraoxon could be achieved. The details of fabrication of the sensor and the dependence of the sensitivity have been discussed.
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Affiliation(s)
- Neetu Jha
- Alternative Energy Technology Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
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Yao JJ, Gao NY, Li C, Li L, Xu B. Mechanism and kinetics of parathion degradation under ultrasonic irradiation. J Hazard Mater 2010; 175:138-145. [PMID: 19854573 DOI: 10.1016/j.jhazmat.2009.09.140] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 09/27/2009] [Accepted: 09/28/2009] [Indexed: 05/27/2023]
Abstract
The parathion degradation under ultrasonic irradiation in aqueous solution was investigated. The results indicate that at the conditions in question, degradation rate of parathion decreased with increasing initial concentration and decreasing power. The optimal frequency for parathion degradation was 600 kHz. The free radical reactions predominate in the sonochemical degradation of parathion and the reaction zones are predominately at the bubble interface and, to a much lesser extent, in bulk solution. The gas/liquid interfacial regions are the real effective reaction sites for sonochemical degradation of parathion. The reaction can be well described as a gas/liquid heterogeneous reaction which obeys a kinetic model based on Langmuir-Hinshelwood model. The main pathways of parathion degradation by ultrasonic irradiation were also proposed by qualitative and quantitative analysis of organic and inorganic byproducts. It is indicated that the N(2) in air takes part in the parathion degradation through the formation of NO(2) under ultrasonic irradiation. Parathion is decomposed into paraoxon and 4-nitrophenol in the first step via two different pathways, respectively, which is in agreement with the theoretical molecular orbital (MO) calculations.
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Affiliation(s)
- Juan-Juan Yao
- State Key laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.
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Bharate SB, Guo L, Reeves TE, Cerasoli DM, Thompson CM. Bisquaternary pyridinium oximes: Comparison of in vitro reactivation potency of compounds bearing aliphatic linkers and heteroaromatic linkers for paraoxon-inhibited electric eel and recombinant human acetylcholinesterase. Bioorg Med Chem 2010; 18:787-94. [PMID: 20005727 PMCID: PMC2818686 DOI: 10.1016/j.bmc.2009.11.052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2009] [Revised: 11/18/2009] [Accepted: 11/21/2009] [Indexed: 11/26/2022]
Abstract
Oxime reactivators are the drugs of choice for the post-treatment of OP (organophosphorus) intoxication and used widely for mechanistic and kinetic studies of OP-inhibited cholinesterases. The purpose of the present study was to evaluate new oxime compounds to reactivate acetylcholinesterase (AChE) inhibited by the OP paraoxon. Several new bisquaternary pyridinium oximes with heterocyclic linkers along with some known bisquaternary pyridinium oximes bearing aliphatic linkers were synthesized and evaluated for their in vitro reactivation potency against paraoxon-inhibited electric eel acetylcholinesterase (EeAChE) and recombinant human acetylcholinesterase (rHuAChE). Results herein indicate that most of the compounds are better reactivators of EeAChE than of rHuAChE. The reactivation potency of two different classes of compounds with varying linker chains was compared and observed that the structure of the connecting chain is an important factor for the activity of the reactivators. At a higher concentration (10(-3)M), compounds bearing aliphatic linker showed better reactivation than compounds with heterocyclic linkers. Interestingly, oximes with a heterocyclic linker inhibited AChE at higher concentration (10(-3)M), whereas their ability to reactivate was increased at lower concentrations (10(-4)M and 10(-5)M). Compounds bearing either a thiophene linker 26, 46 or a furan linker 31 showed 59%, 49% and 52% reactivation of EeAChE, respectively, at 10(-5)M. These compounds showed 14%, 6% and 15% reactivation of rHuAChE at 10(-4)M. Amongst newly synthesized analogs with heterocyclic linkers (26-35 and 45-46), compound 31, bearing furan linker chain, was found to be the most effective reactivator with a k(r) 0.042min(-1), which is better than obidoxime (3) for paraoxon-inhibited EeAChE. Compound 31 showed a k(r) 0.0041min(-1) that is near equal to pralidoxime (1) for paraoxon-inhibited rHuAChE.
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Affiliation(s)
- Sandip B. Bharate
- NIH COBRE Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA
| | - Lilu Guo
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
| | - Tony E. Reeves
- USAMRICD, Research Division, Physiology and Immunology Branch, 3100 Ricketts Point Road, APG, MD 21010, USA
| | - Douglas M. Cerasoli
- USAMRICD, Research Division, Physiology and Immunology Branch, 3100 Ricketts Point Road, APG, MD 21010, USA
| | - Charles M. Thompson
- NIH COBRE Center for Structural and Functional Neuroscience, Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT 59812, USA
- ATERIS Technologies LLC, 901 N Orange Street, Missoula, MT 59802, USA
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Zhang X, Wu R, Song L, Lin Y, Lin M, Cao Z, Wu W, Mo Y. Molecular dynamics simulations of the detoxification of paraoxon catalyzed by phosphotriesterase. J Comput Chem 2009; 30:2388-401. [PMID: 19353598 PMCID: PMC2754597 DOI: 10.1002/jcc.21238] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Combined QM(PM3)/MM molecular dynamics simulations together with QM(DFT)/MM optimizations for key configurations have been performed to elucidate the enzymatic catalysis mechanism on the detoxification of paraoxon by phosphotriesterase (PTE). In the simulations, the PM3 parameters for the phosphorous atom were reoptimized. The equilibrated configuration of the enzyme/substrate complex showed that paraoxon can strongly bind to the more solvent-exposed metal ion Zn(beta), but the free energy profile along the binding path demonstrated that the binding is thermodynamically unfavorable. This explains why the crystal structures of PTE with substrate analogues often exhibit long distances between the phosphoral oxygen and Zn(beta). The subsequent SN2 reaction plays the key role in the whole process, but controversies exist over the identity of the nucleophilic species, which could be either a hydroxide ion terminally coordinated to Zn(alpha) or the micro-hydroxo bridge between the alpha- and beta-metals. Our simulations supported the latter and showed that the rate-limiting step is the distortion of the bound paraoxon to approach the bridging hydroxide. After this preparation step, the bridging hydroxide ion attacks the phosphorous center and replaces the diethyl phosphate with a low barrier. Thus, a plausible way to engineer PTE with enhanced catalytic activity is to stabilize the deformed paraoxon. Conformational analyses indicate that Trp131 is the closest residue to the phosphoryl oxygen, and mutations to Arg or Gln or even Lys, which can shorten the hydrogen bond distance with the phosphoryl oxygen, could potentially lead to a mutant with enhanced activity for the detoxification of organophosphates.
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Affiliation(s)
- Xin Zhang
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008, USA
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Ruibo Wu
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Lingchun Song
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008, USA
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Yuchun Lin
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008, USA
| | - Menghai Lin
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Zexing Cao
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Wei Wu
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Yirong Mo
- Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008, USA
- Department of Chemistry, College of Chemistry and Chemical Engineering, the State Key Laboratory for Physical Chemistry of Solid States, Center for Theoretical Chemistry, Xiamen University, Xiamen, Fujian 361005, P. R. China
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Roy L, Chauve C, Delaporte J, Inizan G, Buronfosse T. Exploration of the susceptibility of AChE from the poultry red mite Dermanyssus gallinae (Acari: Mesostigmata) to organophosphates in field isolates from France. Exp Appl Acarol 2009; 48:19-30. [PMID: 19214761 DOI: 10.1007/s10493-009-9249-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 01/23/2009] [Indexed: 05/27/2023]
Abstract
The red fowl mite Dermanyssus gallinae (De Geer, 1778) is a hematophagous mite species, which is very commonly found in layer facilities in Europe. The economic and animal health impact of this parasite is quite important. In laying hen houses, organophosphates are almost the only legally usable chemicals. Detecting a target resistance can be useful in order to limit the emergence of resistant populations. The acetylcholinesterase (AChE) activity and the enzyme sensitivity to paraoxon was investigated in 39 field samples and compared to a susceptible reference strain (SSK). Insensitivity factor values (expressed as IC50 ratio) obtained from field isolates compared to SSK revealed some polymorphism but not exceeding a 6-fold difference. The kinetic characteristics of AChE from some field samples showed some difference in KM values for acetylthiocholine and inhibition kinetics performed with diethyl paraoxon exhibited a 5.5-fold difference in the bimolecular rate constant in one field isolate. Taken together, these data suggested that differences in AChE susceptibility to organophosphates may exist in D. gallinae but no resistant population was found.
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Affiliation(s)
- Lise Roy
- Ecole Nationale Vétérinaire de Lyon, Laboratoire de parasitologie, Université de Lyon, 69280, Marcy-L'Etoile, France.
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Kuepper U, Musshoff F, Madea B. A fully validated isotope dilution HPLC-MS/MS method for the simultaneous determination of succinylcholine and succinylmonocholine in serum and urine samples. J Mass Spectrom 2008; 43:1344-1352. [PMID: 18438976 DOI: 10.1002/jms.1410] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method for the simultaneous detection of succinylcholine (SUX) and its metabolite succinylmonocholine (SMC) in serum and urine is presented. For internal standardization using isotope dilution, the deuterated compounds SUX-d(18) and SMC-d(3) were employed. Full validation was performed according to international guidelines. Solid-phase extraction (SPE) of acidified samples was accomplished using Strata-X polymeric reversed phase cartridges together with heptafluorobutyric acid (HFBA) as ion-pairing reagent. Separation was achieved within 13 min on a Phenomenex Synergi Hydro RP C18 column (4 microm, 150 x 2 mm) using a gradient of 5 mM ammonium formate buffer pH 3.5 and acetonitrile.To ensure the method's applicability in forensic as well as clinical toxicology, the specific demands of both research fields were taken into account, and the method was thus validated for a low and high concentration range. For both serum and urine as sample matrix, the validation revealed good intraday and interday precisions, consistently ranging below 15% for the lowest and below 10% for elevated concentrations. Accuracy was likewise good and never exceeded 10%. Extraction recovery was excellent, ranging between 88.1 and 103.9% for SUX and SMC in both tested matrices. Matrix effects were significant, the otherwise optimized extraction and detection methods, however, allowed for a very satisfactory sensitivity of the described method: For serum, the limits of detection and quantitation were determined to be 1.9 and 6.0 ng/ml for SUX, as well as 2.5 and 8.6 ng/ml for SMC, respectively; for urine, the corresponding values were established to be 1.4 and 4.0 ng/ml (SUX), as well as 1.5 and 4.9 ng/ml (SMC).The presented method was successfully applied to authentic samples of two forensic cases investigated in the institute of forensic medicine in Bonn, allowing the diagnosis of SUX intoxications.
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Affiliation(s)
- Uta Kuepper
- Institute of Forensic Medicine, University of Bonn, Stiftsplatz 12, 53111 Bonn, Germany.
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38
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Musilek K, Holas O, Kuca K, Jun D, Dohnal V, Dolezal M. Synthesis of a novel series of non-symmetrical bispyridinium compounds bearing a xylene linker and evaluation of their reactivation activity against tabun and paraoxon-inhibited acetylcholinesterase. J Enzyme Inhib Med Chem 2007; 22:425-32. [PMID: 17847708 DOI: 10.1080/14756360601164960] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Nine potential non-symmetrical xylene-bridged AChE reactivators were synthesized using modifications of currently known synthetic pathways. Their potency to reactivate AChE inhibited by the nerve agent tabun and the insecticide paraoxon together with nine symmetrical xylene-bridged compounds, was tested in vitro. Seven compounds were promising against paraoxon-inhibited AChE. Two compounds were found to be more potent against tabun-inhibited AChE than obidoxime at a concentration applicable in vivo.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic.
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Wu J, Lin L, Luan T, Chan Gilbert YS, Lan C. Effects of organophosphorus pesticides and their ozonation byproducts on gap junctional intercellular communication in rat liver cell line. Food Chem Toxicol 2007; 45:2057-63. [PMID: 17601646 DOI: 10.1016/j.fct.2007.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 12/13/2006] [Accepted: 05/10/2007] [Indexed: 11/22/2022]
Abstract
The effects of organophosphorus pesticides (OPs), oxons and their ozonation byproducts on gap junctional intercellular communication (GJIC) on cultured BRL cell line were investigated using scrape loading and dye transfer (SL/DT) technique. The neutral red uptake assay was used to identify the non-cytotoxic levels of diazinon, parathion and methyl-parathion applied to GJIC assay. The concentration-dependent inhibition of GJIC was observed over a range of 50-350 mg/l diazinon, parathion and methyl-parathion after 90 min incubation compared with the vehicle control. However, oxons and ozonation byproducts of OPs had no inhibition effect on GJIC at any of the concentrations tested. The inhibition of GJIC by OPs was reversible after removal of the tested pesticides followed by incubation with fresh medium. The present study suggested that the ozonation treatment could be used for the detoxification of drinking water and food crops contaminated with diazinon, parathion and methyl-parathion without formation of GJIC toxicity.
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Affiliation(s)
- Jiguo Wu
- State Key Laboratory of Biocontrol, School of Life Sciences, Zhongshan (Sun Yat-sen) University, Guangzhou 510275, PR China
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40
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Yang GY, Oh KA, Park NJ, Jung YS. New oxime reactivators connected with CH2O(CH2)nOCH2 linker and their reactivation potency for organophosphorus agents-inhibited acetylcholinesterase. Bioorg Med Chem 2007; 15:7704-10. [PMID: 17869525 DOI: 10.1016/j.bmc.2007.08.056] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 08/27/2007] [Accepted: 08/28/2007] [Indexed: 10/22/2022]
Abstract
New bis-pyridinium oxime reactivators 6 with CH(2)O(CH(2))(2)OCH(2) and CH(2)O(CH(2))(4)OCH(2) linkers between the two pyridinium rings were designed and synthesized. In the in vitro test of their potency to reactivate AChE inhibited by organophosphorus agents at 5 x 10(-3)M concentration, the reactivation ability of 1,2-dimethoxy-ethylene-bis-N,N'-4-pyridiumaldoxime dichloride (6a) was 63% for housefly (HF) AChE inhibited by diisopropyl fluorophosphates (DFP), 51% for bovine red blood cell (RBC) AChE inhibited by DFP, 67% for HF-AChE inhibited by paraoxon, and 81% for RBC-AChE inhibited by paraoxon. Except in the case of DFP-inhibited HF AChE test of 2-PAM, the activities of 6a are much higher than the activities of 2-PAM and HI-6 which are AChE reactivators currently in use.
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Affiliation(s)
- Garp Yeol Yang
- Drug Discovery Division, Korea Research Institute of Chemical Technology, PO Box 107, Yuseong, Daejeon 305-600, Republic of Korea
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Schofield DA, Westwater C, Barth JL, DiNovo AA. Development of a yeast biosensor–biocatalyst for the detection and biodegradation of the organophosphate paraoxon. Appl Microbiol Biotechnol 2007; 76:1383-94. [PMID: 17665192 DOI: 10.1007/s00253-007-1107-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 06/27/2007] [Accepted: 06/28/2007] [Indexed: 10/23/2022]
Abstract
Organophosphate (OP) poisoning can occur through unintentional exposure to OP pesticides, or by the deliberate release of OP nerve agents. Consequently, there is considerable interest in the development of systems that can detect and/or biodegrade these agents. The aim of this study was to generate a prototype fluorescent reporter yeast biosensor that could detect and biodegrade the model OP pesticide, paraoxon, and subsequently detect paraoxon hydrolysis. Saccharomyces cerevisiae was engineered to hydrolyze paraoxon through the heterologous expression of the Flavobacterium species opd (organophosphate degrading) gene. Global transcription profiling was subsequently used to identify yeast genes, which were induced in the presence of paraoxon, and genes, which were associated with paraoxon hydrolysis. Paraoxon-inducible genes and genes associated with paraoxon hydrolysis were identified. Candidate paraoxon-inducible promoters were cloned and fused to the yeast-enhanced green fluorescent protein (yEGFP), and candidate promoters associated with paraoxon hydrolysis were fused to the red fluorescent protein (yDsRed). The ability of the yeast biosensor to detect paraoxon and paraoxon hydrolysis was demonstrated by the specific induction of the fluorescent reporter (yEGFP and yDsRed, respectively). Biosensors responded to paraoxon in a dose- and time-dependent manner, and detection was rapid (15 to 30 min). yDsRed induction occurred only in the recombinant opd(+) strains suggesting that yDsRed induction was strictly associated with paraoxon hydrolysis. Together, these results indicate that the yeast biocatalyst-biosensor can detect and degrade paraoxon and potentially also monitor the decontamination process.
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Affiliation(s)
- David A Schofield
- Guild Associates Inc., 1313B Ashley River Road, Charleston, SC 29407, USA.
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Kim SH, Kim JH, Kang BK. Decomposition reaction of organophosphorus nerve agents on solid surfaces with atmospheric radio frequency plasma generated gaseous species. Langmuir 2007; 23:8074-8. [PMID: 17579467 DOI: 10.1021/la700692t] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The decomposition and detoxification of compounds are of great interest in environmental protection and defense-related areas. We report the generation of gaseous excited species by scanning atmospheric radio frequency (rf) plasma and their reactions with two representative organophosphorus nerve agents, paraoxon and parathion, deposited on solid surfaces. The excited gaseous species generated in the Ar and Ar/O2 plasma were identified as atomic oxygen, OH radical, and excited nitrogen molecule from optical emission spectroscopy analysis. The reaction of these species with paraoxon and parathion was monitored with reflection-absorption infrared spectroscopy and compared with the decomposition by UV irradiation and UV/ozone treatments. The decomposition products of the atmospheric rf plasma treatment were similar to those of the UV/ozone treatment. The atomic oxygen and excited OH species generated by the plasma appear to be responsible for the oxidation of paraoxon and parathion. The plasma-induced decomposition process was much faster and more efficient than the UV/ozone process. The complete detoxification of paraoxon and parathion upon a short time exposure to the Ar/O2 plasma was confirmed by the Drosophila melanogaster culture test.
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Affiliation(s)
- Seong H Kim
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
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Ghanem E, Li Y, Xu C, Raushel FM. Characterization of a phosphodiesterase capable of hydrolyzing EA 2192, the most toxic degradation product of the nerve agent VX. Biochemistry 2007; 46:9032-40. [PMID: 17630782 DOI: 10.1021/bi700561k] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glycerophosphodiesterase (GpdQ) from Enterobacter aerogenes is a nonspecific diesterase that enables Escherichia coli to utilize alkyl phosphodiesters, such as diethyl phosphate, as the sole phosphorus source. The catalytic properties of GpdQ were determined, and the best substrate found was bis(p-nitrophenyl) phosphate with a kcat/Km value of 6.7 x 10(3) M-1 s-1. In addition, the E. aerogenes diesterase was tested as a catalyst for the hydrolysis of a series of phosphonate monoesters which are the hydrolysis products of the highly toxic organophosphonate nerve agents sarin, soman, GF, VX, and rVX. Among the phosphonate monoesters tested, the hydrolysis product of rVX, isobutyl methyl phosphonate, was the best substrate with a kcat/Km value of 33 M-1 s-1. The ability of GpdQ to hydrolyze the phosphonate monoesters provides an alternative selection strategy in the search of enhanced variants of the bacterial phosphotriesterase (PTE) for the hydrolysis of organophosphonate nerve agents. This investigation demonstrated that the previously reported activity of GpdQ toward the hydrolysis of methyl demeton-S is due to the presence of a diester contaminant in the commercial material. Furthermore, it was shown that GpdQ is capable of hydrolyzing a close analogue of EA 2192, the most toxic and persistent degradation product of the nerve agent VX.
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Affiliation(s)
- Eman Ghanem
- Department of Chemistry, P.O. Box 30012, Texas A&M University, College Station, Texas 77842, USA
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Paliwal S, Wales M, Good T, Grimsley J, Wild J, Simonian A. Fluorescence-based sensing of p-nitrophenol and p-nitrophenyl substituent organophosphates. Anal Chim Acta 2007; 596:9-15. [PMID: 17616234 DOI: 10.1016/j.aca.2007.05.034] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2006] [Revised: 05/17/2007] [Accepted: 05/23/2007] [Indexed: 11/20/2022]
Abstract
A novel detection method for organophosphate neurotoxins has been described, based on the fluorescence quenching of a Coumarin derivative. These dyes are similar in structure to some organophosphates (OPs), and they fluoresce in the blue-green region of the spectra. This methodology has been utilized for the detection of organophosphates whose hydrolysis product is p-nitrophenol by using an enzyme, organophosphorus hydrolase (OPH). Coumarin1 in the presence of p-nitrophenol results in a quenching of fluorescence, providing a direct measure of the concentration of p-nitrophenol present in the sample. The decrease in fluorescence intensity is proportional to the paraoxon concentration in the range of 7.0x10(-7)-1.7x10(-4) M. The specificity of this sensing application for p-nitrophenyl substituent OPs has also been demonstrated. OPs are a class of synthetic organic pesticides which generally have a short residual life and can cause numerous acute and chronic health effects. They have been an integral part of the agricultural industry for the past several decades due to their target specificities and selectable toxicities. The toxic nature of these compounds can be attributed to the species-specific inhibition of acetylcholinesterase (AChE), an important enzyme responsible for the regeneration of neural synaptic function. In addition to their wide agricultural and urban usage, they have also been exploited for the development of neurological chemical warfare agents. Currently available technologies for OP detection include sol-gel thin films, screen printed electrodes, acoustic patterning, gas chromatography-mass spectrometry, and various other intricate techniques that have limited field applicabilities. This optically-based approach promises much simpler and more direct detection capabilities.
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Affiliation(s)
- Sheetal Paliwal
- Materials Research and Education Center, Auburn University, United States
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45
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Ileperuma NR, Marshall SDG, Squire CJ, Baker HM, Oakeshott JG, Russell RJ, Plummer KM, Newcomb RD, Baker EN. High-resolution crystal structure of plant carboxylesterase AeCXE1, from Actinidia eriantha, and its complex with a high-affinity inhibitor paraoxon. Biochemistry 2007; 46:1851-9. [PMID: 17256879 DOI: 10.1021/bi062046w] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carboxylesterases (CXEs) are widely distributed in plants, where they have been implicated in roles that include plant defense, plant development, and secondary metabolism. We have cloned, overexpressed, purified, and crystallized a carboxylesterase from the kiwifruit species Actinidia eriantha (AeCXE1). The structure of AeCXE1 was determined by X-ray crystallography at 1.4 A resolution. The crystal structure revealed that AeCXE1 is a member of the alpha/beta-hydrolase fold superfamily, most closely related structurally to the hormone-sensitive lipase subgroup. The active site of the enzyme, located in an 11 A deep hydrophobic gorge, contains the conserved catalytic triad residues Ser169, Asp276, and His306. Kinetic analysis using artificial ester substrates showed that the enzyme can hydrolyze a range of carboxylester substrates with acyl groups ranging from C2 to C16, with a preference for butyryl moieties. This preference was supported by the discovery of a three-carbon acyl adduct bound to the active site Ser169 in the native structure. AeCXE1 was also found to be inhibited by organophosphates, with paraoxon (IC50 = 1.1 muM) a more potent inhibitor than dimethylchlorophosphate (DMCP; IC50 = 9.2 muM). The structure of AeCXE1 with paraoxon bound was determined at 2.3 A resolution and revealed that the inhibitor binds covalently to the catalytic serine residue, with virtually no change in the structure of the enzyme. The structural information for AeCXE1 provides a basis for addressing the wider functional roles of carboxylesterases in plants.
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46
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Zheng J, Desbat B, Rastogi VK, Shah SS, Defrank JJ, Leblanc RM. Organophosphorus Hydrolase at the Air−Water Interface: Secondary Structure and Interaction with Paraoxon. Biomacromolecules 2006; 7:2806-10. [PMID: 17025356 DOI: 10.1021/bm060352j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The secondary structure of organophosphorus hydrolase (OPH) at the air-water interface was studied using polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS). The shape and position of the amide I and amide II bands were used to estimate the surface conformation and orientation of OPH. The PM-IRRAS results indicated that the enzyme did not unfold for the range of surface pressure used (0-30 mN/m). At low surface pressures, the signal of amide I was very weak and the intensity was almost the same as amide II. Upon further compression, the PM-IRRAS signal and the ratio of the intensity of amide I and amide II both increase, implying an increased interfacial concentration of the enzyme. From the amide I/amide II ratio and the band position, it was deduced that the enzyme adopts a conformation which gives a higher occupied surface at low surface pressure and rotates to a more vertical orientation at high surface pressures. The compression and decompression of the OPH monolayer indicated that the fingerprint of the secondary structure at the air-water interface was reversible. PM-IRRAS was also used to investigate the pH effect of the subphase on the secondary structure of OPH. The secondary structure of OPH at the air-water interface was well defined when the pH of the subphase was near its isoelectric point (IP, pH 7.6). However, it adopted a different orientation when the subphase pH values were higher or lower than the IP with formation of random coil structure. The hydrolysis of organophosphorus compound paraoxon by OPH was also studied at the air-water interface by PM-IRRAS. The pH effect and the interaction with paraoxon both seem to orientate the enzyme more in the plane of the interface and to produce random coil structure.
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Affiliation(s)
- Jiayin Zheng
- Department of Chemistry, University of Miami, Coral Gables, Florida 33124-0431, USA
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Wang C, Li C, Ji X, Orbulescu J, Xu J, Leblanc RM. Peptidolipid as binding site of acetylcholinesterase: molecular recognition of paraoxon in Langmuir films. Langmuir 2006; 22:2200-4. [PMID: 16489807 DOI: 10.1021/la052818+] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Peptidolipid C18H35O (stearoyl)-Phe-Trp-Ser-His-Glu (peptidolipid A) was synthesized and spread at the air-water interface to study the interaction with an organophosphorus compound. Paraoxon, sodium dihydrogen phosphate, or 4-nitrophenyl phosphate disodium was added to the subphase, but only paraoxon changed the surface pressure-area (pi-A) isotherm of peptidolipid A. This indicated a specific interaction between paraoxon and peptidolipid A. To clarify which amino acid residue of peptidolipid A was responsible for the interaction, peptidolipid B, namely, C18H35O-Gly-His-Ser-Glu-Glu, was synthesized and studied as a Langmuir film. The difference between the pi-A isotherms of peptidolipid B in the absence and presence of paraoxon in the subphase was minimal; consequently, the presence of amino acids phenylalanine (Phe) and tryptophan (Trp) in peptidolipid A may explain the interaction between peptidolipid A and paraoxon. The compression-decompression cycles and kinetic studies of peptidolipid A showed that the Langmuir film was stable. The in situ optical properties of the peptidolipid A Langmuir film such as UV-vis and fluorescence spectroscopies were examined to elucidate the interaction between peptidolipid A and paraoxon. UV-vis absorption of peptidolipid A was investigated in the presence and absence of paraoxon in the subphase. The emission maximum of fluorescence of Trp in peptidolipid A was observed at 351 nm on pure water, and the band intensity decreased when the concentration of paraoxon increased in the subphase. This suggested that the Trp was involved in the molecular recognition process. Epifluorescence micrographs showed domains of peptidolipid A on the pure water subphase. In the presence of paraoxon in the subphase, the Langmuir film of peptidolipid A showed a homogeneity, which was another indication of the recognition between paraoxon and peptidolipid A.
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Affiliation(s)
- Chengshan Wang
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA
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Xu Y, Yamamoto N, Ruiz DI, Kubitz DS, Janda KD. Squaric monoamide monoester as a new class of reactive immunization hapten for catalytic antibodies. Bioorg Med Chem Lett 2005; 15:4304-7. [PMID: 16046128 DOI: 10.1016/j.bmcl.2005.06.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Revised: 06/15/2005] [Accepted: 06/16/2005] [Indexed: 11/16/2022]
Abstract
A squaric monoester monoamide motif was employed as an effective reactive immunogen for the discovery of monoclonal antibodies with reactive residue(s) in their combining sites. Two antibodies, 2D4 and 3C8, were uncovered that enhance paraoxon hydrolysis over background. Kinetic analysis of these antibodies was performed and interestingly both undergo a single turnover event due to covalent modification within the antibody combining site. Because antibodies 2D4 and 3C8 result in covalent attachment and thus inactivation of paraoxon, they could be useful probes for investigating paraoxon intoxication.
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Affiliation(s)
- Yang Xu
- The Skaggs Institute for Chemical Biology, Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Abstract
Lipases catalyze the hydrolysis of triglycerides and are activated at the water-lipid interface. Thus, their interaction with amphiphiles such as detergents is relevant for an understanding of their enzymatic mechanism. In this study, we have characterized the effect of nonionic, anionic, cationic, and zwitterionic detergents on the enzymatic activity and thermal stability of Thermomyces lanuginosus lipase (TlL). For all detergents, low concentrations enhance the activity of TlL toward p-nitrophenyl butyrate by more than an order of magnitude; at higher detergent concentrations, the activity declines, leveling off close to the value measured in the absence of detergent. Surprisingly, these phenomena mainly involve monomeric detergent, as activation and inhibition occur well below the cmc for the nonionic and zwitterionic detergents. For anionic and cationic detergents, activation straddles the monomer-micelle transition. The data can be fitted to a three state interaction model, comprising free TlL in the absence of detergent, an activated complex with TlL at low detergent concentrations, and an enzyme-inhibiting complex at higher concentrations. For detergents with the same headgroup, there is an excellent correspondence between carbon chain length and ability to activate and inhibit TlL. However, the headgroup and number of chains also modulate these effects, dividing the detergents overall into three broad groups with rising activation and inhibition ability, namely, anionic and cationic detergents, nonionic and single-chain zwitterionic detergents, and double-chain zwitterionic detergents. As expected, only anionic and cationic detergents lead to a significant decrease in lipase thermal stability. Since nonionic detergents activate TlL without destabilizing the protein, activation/inhibition and destabilization must be independent processes. We conclude that lipase-detergent interactions occur at many independent levels and are governed by a combination of general and structurally specific interactions. Furthermore, activation of TlL by detergents apparently does not involve the classical interfacial activation phenomenon as monomeric detergent molecules are in most cases responsible for the observed increase in activity.
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Affiliation(s)
- Jesper E Mogensen
- Department of Life Sciences, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark
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Saffih-Hdadi K, Bruckler L, Amichot M, Belzunces L. Modeling impact of parathion and its metabolite paraoxon on the nematode Caenorhabditis elegans in soil. Environ Toxicol Chem 2005; 24:1387-94. [PMID: 16117114 DOI: 10.1897/04-318r.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Parathion is an insecticide of a group of highly toxic organophosphorous compounds. In vivo, it is activated to the toxic metabolite paraoxon. Laboratory experiments have shown that a single relationship between the variable (concentration x time of application) and the percentage of paralyzed nematodes is relevant. Aqueous (0.01 M CaCl2) extracts from soil that had received a dose of parathion as used in practice during an incubation experiment had no effect on nematodes, because sorption and biodegradation of the pesticide decreased the pesticide concentration in the soluble phase. To predict the toxicological effects of parathion and paraoxon on nematodes under various soil conditions during a simulation period of 20 d, we used a model predicting the concentrations of parathion and paraoxon over time in the soil liquid phase. In this model, sorption and biodegradation of both parathion and paraoxon were taken into account, and the results indicated that sorption effects were dominant and determined the differential toxicological risks between soils. Variable effects were predicted for short times (typically <5 d), and critical toxicological conditions were predicted for longer duration (typically >10-15 d), in all cases.
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Affiliation(s)
- Kawtar Saffih-Hdadi
- CSE-Sol, INRA, Domaine St Paul, Site Agroparc, 84914 Avignon Cedex 09, France
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