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Rupa SA, Patwary MAM, Matin MM, Ghann WE, Uddin J, Kazi M. Interaction of mercury species with proteins: towards possible mechanism of mercurial toxicology. Toxicol Res (Camb) 2023; 12:355-368. [PMID: 37397928 PMCID: PMC10311172 DOI: 10.1093/toxres/tfad039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 05/02/2023] [Accepted: 05/15/2023] [Indexed: 07/04/2023] Open
Abstract
The nature of the binding of mercurials (organic and inorganic) and their subsequent transformations in biological systems is a matter of great debate as several different hypotheses have been proposed and none of them has been conclusively proven to explain the characteristics of Hg binding with the proteins. Thus, the chemical nature of Hg-protein binding through the possible transportation mechanism in living tissues is critically reviewed herein. Emphasis is given to the process of transportation, and binding of Hg species with selenol-containing biomolecules that are appealing for toxicological studies as well as the advancement of environmental and biological research.
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Affiliation(s)
| | | | | | - William Emmanuel Ghann
- Center for Nanotechnology, Department of Natural Sciences, Coppin State University, Baltimore, MD 21216, USA
| | - Jamal Uddin
- Center for Nanotechnology, Department of Natural Sciences, Coppin State University, Baltimore, MD 21216, USA
| | - Mohsin Kazi
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. BOX-2457, Riyadh 11451, Saudi Arabia
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2
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Selective Determination of Glutathione Using a Highly Emissive Fluorescent Probe Based on a Pyrrolidine-Fused Chlorin. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020568. [PMID: 36677627 PMCID: PMC9862258 DOI: 10.3390/molecules28020568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/16/2022] [Accepted: 12/27/2022] [Indexed: 01/09/2023]
Abstract
We report the use of a carboxylated pyrrolidine-fused chlorin (TCPC) as a fluorescent probe for the determination of glutathione (GSH) in 7.4 pH phosphate buffer. TCPC is a very stable, highly emissive molecule that has been easily obtained from meso-tetrakis(4-methoxycarbonylphenyl) porphyrin (TCPP) through a 1,3-dipolar cycloaddition approach. First, we describe the coordination of TCPC with Hg(II) ions and the corresponding spectral changes, mainly characterized by a strong quenching of the chlorin emission band. Then, the TCPC-Hg2+ complex exhibits a significant fluorescence turn-on in the presence of low concentrations of the target analyte GSH. The efficacy of the sensing molecule was tested by using different TCPC:Hg2+ concentration ratios (1:2, 1:5 and 1:10) that gave rise to sigmoidal response curves in all cases with modulating detection limits, being the lowest 40 nM. The experiments were carried out under physiological conditions and the selectivity of the system was demonstrated against a number of potential interferents, including cysteine. Furthermore, the TCPC macrocycle did not showed a significant fluorescent quenching in the presence of other metal ions.
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Łuczkowski M, Padjasek M, Ba Tran J, Hemmingsen L, Kerber O, Habjanič J, Freisinger E, Krężel A. An Extremely Stable Interprotein Tetrahedral Hg(Cys) 4 Core Forms in the Zinc Hook Domain of Rad50 Protein at Physiological pH. Chemistry 2022; 28:e202202738. [PMID: 36222310 PMCID: PMC9828754 DOI: 10.1002/chem.202202738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Indexed: 11/09/2022]
Abstract
In nature, thiolate-based systems are the primary targets of divalent mercury (HgII ) toxicity. The formation of Hg(Cys)x cores in catalytic and structural protein centers mediates mercury's toxic effects and ultimately leads to cellular damage. Multiple studies have revealed distinct HgII -thiolate coordination preferences, among which linear HgII complexes are the most commonly observed in solution at physiological pH. Trigonal or tetrahedral geometries are formed at basic pH or in tight intraprotein Cys-rich metal sites. So far, no interprotein tetrahedral HgII complex formed at neutral pH has been reported. Rad50 protein is a part of the multiprotein MRN complex, a major player in DNA damage-repair processes. Its central region consists of a conserved CXXC motif that enables dimerization of two Rad50 molecules by coordinating ZnII . Dimerized motifs form a unique interprotein zinc hook domain (Hk) that is critical for the biological activity of the MRN. Using a series of length-differentiated peptide models of the Pyrococcus furiosus zinc hook domain, we investigated its interaction with HgII . Using UV-Vis, CD, PAC, and 199 Hg NMR spectroscopies as well as anisotropy decay, we discovered that all Rad50 fragments preferentially form homodimeric Hg(Hk)2 species with a distorted tetrahedral HgS4 coordination environment at physiological pH; this is the first example of an interprotein mercury site displaying tetrahedral geometry in solution. At higher HgII content, monomeric HgHk complexes with linear geometry are formed. The Hg(Cys)4 core of Rad50 is extremely stable and does not compete with cyanides, NAC, or DTT. Applying ITC, we found that the stability constant of the Rad50 Hg(Hk)2 complex is approximately three orders of magnitude higher than those of the strongest HgII complexes known to date.
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Affiliation(s)
- Marek Łuczkowski
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Michał Padjasek
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Józef Ba Tran
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Lars Hemmingsen
- Department of ChemistryUniversity of CopenhagenUniversitetsparken 52100København ØDenmark
| | - Olga Kerber
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
| | - Jelena Habjanič
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZürichSwitzerland
| | - Eva Freisinger
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZürichSwitzerland
| | - Artur Krężel
- Department of Chemical BiologyFaculty of BiotechnologyUniversity of WrocławJoliot-Curie 14a50-383WrocławPoland
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Oliveira CS, Nogara PA, Lima LS, Galiciolli ME, Souza JV, Aschner M, Rocha JB. Toxic metals that interact with thiol groups and alteration in insect behavior. CURRENT OPINION IN INSECT SCIENCE 2022; 52:100923. [PMID: 35462063 DOI: 10.1016/j.cois.2022.100923] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/17/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Toxic metals, such as mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu), are widespread in the biosphere, and human activities have contributed to their continuous release into the ecosystems. Metal-induced toxicity has been extensively studied in mammals; however, the effects of these metals on insects' behavior have been explored to far lesser degree. As the main mechanism of toxicity, the cationic metals, explored in this review, have high affinity for thiol-containing molecules, disrupting the function of several proteins and low-molecular-weight thiol-containing molecules. Existing literature has corroborated that Hg, Pb, Cd, and Cu can disrupt locomotor and mating behaviors, but their effects on insects' memory and learning have yet to be fully characterized. Though field studies on metal-induced toxicity in insects are limited, results from Drosophila melanogaster as an experimental model suggest that insects living in contaminated environments can have behavioral foraging and reproductive deficits, which may cause population decline. In this review, we address the interaction between metals and endogenous thiol groups, with emphasis on alterations in insect behavior.
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Affiliation(s)
- Cláudia S Oliveira
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, PR, Brazil; Faculdades Pequeno Príncipe, Curitiba, PR, Brazil
| | - Pablo A Nogara
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Luíza S Lima
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, PR, Brazil; Faculdades Pequeno Príncipe, Curitiba, PR, Brazil
| | - Maria Ea Galiciolli
- Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, PR, Brazil; Faculdades Pequeno Príncipe, Curitiba, PR, Brazil
| | | | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - João Bt Rocha
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
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Cao Y, Yang L, Ding P, Li W, Pei R. Ligand Selectivity by Inserting GCGC‐Tetrads into G‐Quadruplex Structures. Chemistry 2020; 26:14730-14737. [DOI: 10.1002/chem.202003004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/22/2020] [Indexed: 12/22/2022]
Affiliation(s)
- Yanwei Cao
- CAS Key Laboratory of Nano-Bio Interface Division of Nanobiomedicine Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou 215123 P. R. China
| | - Luyan Yang
- CAS Key Laboratory of Nano-Bio Interface Division of Nanobiomedicine Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou 215123 P. R. China
| | - Pi Ding
- CAS Key Laboratory of Nano-Bio Interface Division of Nanobiomedicine Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou 215123 P. R. China
| | - Wenjing Li
- CAS Key Laboratory of Nano-Bio Interface Division of Nanobiomedicine Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou 215123 P. R. China
| | - Renjun Pei
- CAS Key Laboratory of Nano-Bio Interface Division of Nanobiomedicine Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou 215123 P. R. China
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Ajsuvakova OP, Tinkov AA, Aschner M, Rocha JB, Michalke B, Skalnaya MG, Skalny AV, Butnariu M, Dadar M, Sarac I, Aaseth J, Bjørklund G. Sulfhydryl groups as targets of mercury toxicity. Coord Chem Rev 2020; 417:213343. [PMID: 32905350 PMCID: PMC7470069 DOI: 10.1016/j.ccr.2020.213343] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The present study addresses existing data on the affinity and conjugation of sulfhydryl (thiol; -SH) groups of low- and high-molecular-weight biological ligands with mercury (Hg). The consequences of these interactions with special emphasis on pathways of Hg toxicity are highlighted. Cysteine (Cys) is considered the primary target of Hg, and link its sensitivity with thiol groups and cellular damage. In vivo, Hg complexes play a key role in Hg metabolism. Due to the increased affinity of Hg to SH groups in Cys residues, glutathione (GSH) is reactive. The geometry of Hg(II) glutathionates is less understood than that with Cys. Both Cys and GSH Hg-conjugates are important in Hg transport. The binding of Hg to Cys mediates multiple toxic effects of Hg, especially inhibitory effects on enzymes and other proteins that contain free Cys residues. In blood plasma, albumin is the main Hg-binding (Hg2+, CH3Hg+, C2H5Hg+, C6H5Hg+) protein. At the Cys34 residue, Hg2+ binds to albumin, whereas other metals likely are bound at the N-terminal site and multi-metal binding sites. In addition to albumin, Hg binds to multiple Cys-containing enzymes (including manganese-superoxide dismutase (Mn-SOD), arginase I, sorbitol dehydrogenase, and δ-aminolevulinate dehydratase, etc.) involved in multiple processes. The affinity of Hg for thiol groups may also underlie the pathways of Hg toxicity. In particular, Hg-SH may contribute to apoptosis modulation by interfering with Akt/CREB, Keap1/Nrf2, NF-κB, and mitochondrial pathways. Mercury-induced oxidative stress may ensue from Cys-Hg binding and inhibition of Mn-SOD (Cys196), thioredoxin reductase (TrxR) (Cys497) activity, as well as limiting GSH (GS-HgCH3) and Trx (Cys32, 35, 62, 65, 73) availability. Moreover, Hg-thiol interaction also is crucial in the neurotoxicity of Hg by modulating the cytoskeleton and neuronal receptors, to name a few. However, existing data on the role of Hg-SH binding in the Hg toxicity remains poorly defined. Therefore, more research is needed to understand better the role of Hg-thiol binding in the molecular pathways of Hg toxicology and the critical role of thiols to counteract negative effects of Hg overload.
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Affiliation(s)
- Olga P. Ajsuvakova
- Yaroslavl State University, Yaroslavl, Russia
- Federal Scientific Center of Biological Systems and Agrotechnologies of the Russian Academy of Sciences, Orenburg, Russia
- IM Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alexey A. Tinkov
- Yaroslavl State University, Yaroslavl, Russia
- Federal Scientific Center of Biological Systems and Agrotechnologies of the Russian Academy of Sciences, Orenburg, Russia
- IM Sechenov First Moscow State Medical University, Moscow, Russia
| | - Michael Aschner
- IM Sechenov First Moscow State Medical University, Moscow, Russia
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - João B.T. Rocha
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | | | | | - Anatoly V. Skalny
- Yaroslavl State University, Yaroslavl, Russia
- Federal Scientific Center of Biological Systems and Agrotechnologies of the Russian Academy of Sciences, Orenburg, Russia
- IM Sechenov First Moscow State Medical University, Moscow, Russia
| | - Monica Butnariu
- Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timișoara, Timişoara, Romania
- CONEM Romania Biotechnology and Environmental Sciences Group, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timișoara, Timişoara, Romania
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Ioan Sarac
- Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timișoara, Timişoara, Romania
- CONEM Romania Biotechnology and Environmental Sciences Group, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania” from Timișoara, Timişoara, Romania
| | - Jan Aaseth
- IM Sechenov First Moscow State Medical University, Moscow, Russia
- Research Department, Innlandet Hospital Trust, Brumunddal, Norway
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine (CONEM), Mo i Rana, Norway
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Mironov IV, Kharlamova VY. On the Complexation of Gold(I) with Glutathione in Aqueous Solutions. J SOLUTION CHEM 2020. [DOI: 10.1007/s10953-020-00994-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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8
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Experimental and theoretical validations of a one-pot sequential sensing of Hg2+ and biothiols by a 3D Cu-based zwitterionic metal−organic framework. Talanta 2020; 210:120596. [DOI: 10.1016/j.talanta.2019.120596] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 01/11/2023]
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Liang X, Lu X, Zhao J, Liang L, Zeng EY, Gu B. Stepwise Reduction Approach Reveals Mercury Competitive Binding and Exchange Reactions within Natural Organic Matter and Mixed Organic Ligands. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10685-10694. [PMID: 31415168 DOI: 10.1021/acs.est.9b02586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The kinetics of mercuric ion (Hg2+) binding with heterogeneous naturally dissolved organic matter (DOM) has been hypothesized to result from competitive interactions among different organic ligands and functional groups of DOM for Hg2+. However, an experimental protocol is lacking to determine Hg2+ binding with various competitive ligands and DOM, their binding strengths, and their dynamic exchange reactions. In this study, a stepwise reduction approach using ascorbic acid (AA) and stannous tin [Sn(II)] was devised to differentiate Hg(II) species in the presence of two major functional groups in DOM: the carboxylate-bound Hg(II) is reducible by both AA and Sn(II), whereas the thiolate-bound Hg(II) is reducible only by Sn(II). Using this operational approach, the relative binding strength of Hg2+ with selected organic ligands was found in the order dimercaptopropanesulfonate (DMPS) > glutathione (GSH) > penicillamine (PEN) > cysteine (CYS) > ethylenediaminetetraacetate > citrate, acetate, and glycine at the ligand-to-Hg molar ratio < 2. Dynamic, competitive ligand exchanges for Hg2+ from weak carboxylate to strong thiolate functional groups were observed among these ligands and within DOM, and the reaction depended on the relative binding strength and abundance of thiols and carboxylates, as well as reaction time. These results provide additional insights into dynamic exchange reactions of Hg2+ within multicompositional DOM in controlling the transformation and bioavailability of Hg(II) in natural aquatic environments.
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Affiliation(s)
- Xujun Liang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment , Jinan University , Guangzhou 511443 , China
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Xia Lu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- College of Earth and Environmental Sciences , Lanzhou University , Lanzhou 730000 , China
| | - Jiating Zhao
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Liyuan Liang
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Eddy Y Zeng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment , Jinan University , Guangzhou 511443 , China
| | - Baohua Gu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Biosystems Engineering and Soil Science , University of Tennessee , Knoxville , Tennessee 37996 , United States
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Liu X, Dong L, Wang L, Xu H, Gao S, Zhong L, Zhang S, Jiang T. 2-Aminopurine modified DNA probe for rapid and sensitive detection of l-cysteine. Talanta 2019; 202:520-525. [DOI: 10.1016/j.talanta.2019.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/15/2019] [Accepted: 05/02/2019] [Indexed: 02/09/2023]
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11
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Tortora F, Notariale R, Maresca V, Good KV, Sorbo S, Basile A, Piscopo M, Manna C. Phenol-Rich Feijoa sellowiana (Pineapple Guava) Extracts Protect Human Red Blood Cells from Mercury-Induced Cellular Toxicity. Antioxidants (Basel) 2019; 8:E220. [PMID: 31336755 PMCID: PMC6680458 DOI: 10.3390/antiox8070220] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 06/21/2019] [Accepted: 07/08/2019] [Indexed: 02/06/2023] Open
Abstract
Plant polyphenols, with broadly known antioxidant properties, represent very effective agents against environmental oxidative stressors, including mercury. This heavy metal irreversibly binds thiol groups, sequestering endogenous antioxidants, such as glutathione. Increased incidence of food-derived mercury is cause for concern, given the many severe downstream effects, ranging from kidney to cardiovascular diseases. Therefore, the possible beneficial properties of Feijoa sellowiana against mercury toxicity were tested using intact human red blood cells (RBC) incubated in the presence of HgCl2. Here, we show that phenol-rich (10-200 µg/mL) extracts from the Feijoa sellowiana fruit potently protect against mercury-induced toxicity and oxidative stress. Peel and pulp extracts are both able to counteract the oxidative stress and thiol decrease induced in RBC by mercury treatment. Nonetheless, the peel extract had a greater protective effect compared to the pulp, although to a different extent for the different markers analyzed, which is at least partially due to the greater proportion and diversity of polyphenols in the peel. Furthermore, Fejioa sellowiana extracts also prevent mercury-induced morphological changes, which are known to enhance the pro-coagulant activity of these cells. These novel findings provide biochemical bases for the pharmacological use of Fejioa sellowiana-based functional foods in preventing and combating mercury-related illnesses.
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Affiliation(s)
- Fabiana Tortora
- Department of Precision Medicine, School of Medicine, University of Campania "Luigi Vanvitelli", via Luigi de Crecchio, 80138 Naples, Italy
| | - Rosaria Notariale
- Department of Precision Medicine, School of Medicine, University of Campania "Luigi Vanvitelli", via Luigi de Crecchio, 80138 Naples, Italy
| | - Viviana Maresca
- Department of Biology, University of Naples Federico II, via Cupa Nuova Cinthia, 80126 Naples, Italy
| | - Katrina Vanessa Good
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, BC V8W 3R4, Canada
| | - Sergio Sorbo
- Ce.S.M.A, Microscopy Section, University of Naples Federico II, via Cupa Nuova Cinthia, 80126 Naples, Italy
| | - Adriana Basile
- Department of Biology, University of Naples Federico II, via Cupa Nuova Cinthia, 80126 Naples, Italy
| | - Marina Piscopo
- Department of Biology, University of Naples Federico II, via Cupa Nuova Cinthia, 80126 Naples, Italy.
| | - Caterina Manna
- Department of Precision Medicine, School of Medicine, University of Campania "Luigi Vanvitelli", via Luigi de Crecchio, 80138 Naples, Italy.
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Superoxide Dismutase and Pseudocatalase Increase Tolerance to Hg(II) in Thermus thermophilus HB27 by Maintaining the Reduced Bacillithiol Pool. mBio 2019; 10:mBio.00183-19. [PMID: 30940703 PMCID: PMC6445937 DOI: 10.1128/mbio.00183-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thermus thermophilus is a deep-branching thermophilic aerobe. It is a member of the Deinococcus-Thermus phylum that, together with the Aquificae, constitute the earliest branching aerobic bacterial lineages; therefore, this organism serves as a model for early diverged bacteria (R. K. Hartmann, J. Wolters, B. Kröger, S. Schultze, et al., Syst Appl Microbiol 11:243–249, 1989, https://doi.org/10.1016/S0723-2020(89)80020-7) whose natural heated habitat may contain mercury of geological origins (G. G. Geesey, T. Barkay, and S. King, Sci Total Environ 569-570:321–331, 2016, https://doi.org/10.1016/j.scitotenv.2016.06.080). T. thermophilus likely arose shortly after the oxidation of the biosphere 2.4 billion years ago. Studying T. thermophilus physiology provides clues about the origin and evolution of mechanisms for mercury and oxidative stress responses, the latter being critical for the survival and function of all extant aerobes. Mercury (Hg) is a widely distributed, toxic heavy metal with no known cellular role. Mercury toxicity has been linked to the production of reactive oxygen species (ROS), but Hg does not directly perform redox chemistry with oxygen. How exposure to the ionic form, Hg(II), generates ROS is unknown. Exposure of Thermus thermophilus to Hg(II) triggered ROS accumulation and increased transcription and activity of superoxide dismutase (Sod) and pseudocatalase (Pcat); however, Hg(II) inactivated Sod and Pcat. Strains lacking Sod or Pcat had increased oxidized bacillithiol (BSH) levels and were more sensitive to Hg(II) than the wild type. The ΔbshA Δsod and ΔbshA Δpcat double mutant strains were as sensitive to Hg(II) as the ΔbshA strain that lacks bacillithiol, suggesting that the increased sensitivity to Hg(II) in the Δsod and Δpcat mutant strains is due to a decrease of reduced BSH. Treatment of T. thermophilus with Hg(II) decreased aconitase activity and increased the intracellular concentration of free Fe, and these phenotypes were exacerbated in Δsod and Δpcat mutant strains. Treatment with Hg(II) also increased DNA damage. We conclude that sequestration of the redox buffering thiol BSH by Hg(II), in conjunction with direct inactivation of ROS-scavenging enzymes, impairs the ability of T. thermophilus to effectively metabolize ROS generated as a normal consequence of growth in aerobic environments.
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Zhang L, Wu S, Zhao L, Lu X, Pierce EM, Gu B. Mercury Sorption and Desorption on Organo-Mineral Particulates as a Source for Microbial Methylation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2426-2433. [PMID: 30702880 DOI: 10.1021/acs.est.8b06020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In natural freshwater and sediments, mercuric mercury (Hg(II)) is largely associated with particulate minerals and organics, but it remains unclear under what conditions particulates may become a sink or a source for Hg(II) and whether the particulate-bound Hg(II) is bioavailable for microbial uptake and methylation. In this study, we investigated Hg(II) sorption-desorption characteristics on three organo-coated hematite particulates and a Hg-contaminated natural sediment and evaluated the potential of particulate-bound Hg(II) for microbial methylation. Mercury rapidly sorbed onto particulates, especially the cysteine-coated hematite and sediment, with little desorption observed (0.1-4%). However, the presence of Hg-binding ligands, such as low-molecular-weight thiols and humic acids, resulted in up to 60% of Hg(II) desorption from the Hg-laden hematite particulates but <6% from the sediment. Importantly, the particulate-bound Hg(II) was bioavailable for uptake and methylation by a sulfate-reducing bacterium Desulfovibrio desulfuricans ND132 under anaerobic incubations, and the methylation rate was 4-10 times higher than the desorption rate of Hg(II). These observations suggest direct contacts and interactions between bacterial cells and the particulate-bound Hg(II), resulting in rapid exchange or uptake of Hg(II) by the bacteria. The results highlight the importance of Hg(II) partitioning at particulate-water interfaces and the role of particulates as a significant source of Hg(II) for methylation in the environment.
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Affiliation(s)
- Lijie Zhang
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Shan Wu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- School of Resource, Environmental and Chemical Engineering , Nanchang University , Nanchang 330031 , China
| | - Linduo Zhao
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Xia Lu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Eric M Pierce
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Baohua Gu
- Environmental Sciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Biosystems Engineering and Soil Science , University of Tennessee , Knoxville , Tennessee 37996 , United States
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Comparative Analysis of the Effects of Olive Oil Hydroxytyrosol and Its 5- S-Lipoyl Conjugate in Protecting Human Erythrocytes from Mercury Toxicity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:9042192. [PMID: 29849921 PMCID: PMC5924984 DOI: 10.1155/2018/9042192] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 03/04/2018] [Indexed: 12/20/2022]
Abstract
Oxidative stress is one of the underlying mechanisms of the toxic effects exerted by mercury (Hg) on human health. Several antioxidant compounds, including the olive oil phenol hydroxytyrosol (HT), were investigated for their protective action. Recently, we have reported that 5-S-lipoylhydroxytyrosol (Lipo-HT) has shown increased antioxidant activities compared to HT and exerted potent protective effects against reactive oxygen species (ROS) generation and oxidative damage in human hepatocellular carcinoma HepG2 cell lines. In this study, the effects of Lipo-HT and HT on oxidative alterations of human erythrocytes induced by exposure to 40 μM HgCl2 were comparatively evaluated. When administered to the cells, Lipo-HT (5–20 μM) proved nontoxic and it decreased the Hg-induced generation of ROS, the hemolysis, and the depletion of intracellular GSH levels. At all tested concentrations, Lipo-HT exhibited higher ability to counteract Hg-induced cytotoxicity compared to HT. Model studies indicated the formation of a mercury complex at the SH group of Lipo-HT followed by a redox reaction that would spare intracellular GSH. Thus, the enhanced erythrocyte protective action of Lipo-HT from Hg-induced damage with respect to HT is likely due to an effective chelating and reducing ability toward mercury ions. These findings encourage the use of Lipo-HT in nutraceutical strategies to contrast heavy metal toxicity in humans.
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Aaseth J, Ajsuvakova OP, Skalny AV, Skalnaya MG, Tinkov AA. Chelator combination as therapeutic strategy in mercury and lead poisonings. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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16
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LaVoie SP, Summers AO. Transcriptional responses of Escherichia coli during recovery from inorganic or organic mercury exposure. BMC Genomics 2018; 19:52. [PMID: 29338696 PMCID: PMC5769350 DOI: 10.1186/s12864-017-4413-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/22/2017] [Indexed: 12/22/2022] Open
Abstract
Background The protean chemical properties of mercury have long made it attractive for diverse applications, but its toxicity requires great care in its use, disposal, and recycling. Mercury occurs in multiple chemical forms, and the molecular basis for the distinct toxicity of its various forms is only partly understood. Global transcriptomics applied over time can reveal how a cell recognizes a toxicant and what cellular subsystems it marshals to repair and recover from the damage. The longitudinal effects on the transcriptome of exponential phase E. coli were compared during sub-acute exposure to mercuric chloride (HgCl2) or to phenylmercuric acetate (PMA) using RNA-Seq. Results Differential gene expression revealed common and distinct responses to the mercurials throughout recovery. Cultures exhibited growth stasis immediately after each mercurial exposure but returned to normal growth more quickly after PMA exposure than after HgCl2 exposure. Correspondingly, PMA rapidly elicited up-regulation of a large number of genes which continued for 30 min, whereas fewer genes were up-regulated early after HgCl2 exposure only some of which overlapped with PMA up-regulated genes. By 60 min gene expression in PMA-exposed cells was almost indistinguishable from unexposed cells, but HgCl2 exposed cells still had many differentially expressed genes. Relative expression of energy production and most metabolite uptake pathways declined with both compounds, but nearly all stress response systems were up-regulated by one or the other mercurial during recovery. Conclusions Sub-acute exposure influenced expression of ~45% of all genes with many distinct responses for each compound, reflecting differential biochemical damage by each mercurial and the corresponding resources available for repair. This study is the first global, high-resolution view of the transcriptional responses to any common toxicant in a prokaryotic model system from exposure to recovery of active growth. The responses provoked by these two mercurials in this model bacterium also provide insights about how higher organisms may respond to these ubiquitous metal toxicants. Electronic supplementary material The online version of this article (10.1186/s12864-017-4413-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stephen P LaVoie
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA.
| | - Anne O Summers
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA.
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Low-Molecular-Weight Thiols and Thioredoxins Are Important Players in Hg(II) Resistance in Thermus thermophilus HB27. Appl Environ Microbiol 2018; 84:AEM.01931-17. [PMID: 29150497 DOI: 10.1128/aem.01931-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/24/2017] [Indexed: 12/31/2022] Open
Abstract
Mercury (Hg), one of the most toxic and widely distributed heavy metals, has a high affinity for thiol groups. Thiol groups reduce and sequester Hg. Therefore, low-molecular-weight (LMW) and protein thiols may be important cell components used in Hg resistance. To date, the role of low-molecular-weight thiols in Hg detoxification remains understudied. The mercury resistance (mer) operon of Thermus thermophilus suggests an evolutionary link between Hg(II) resistance and low-molecular-weight thiol metabolism. The mer operon encodes an enzyme involved in methionine biosynthesis, Oah. Challenge with Hg(II) resulted in increased expression of genes involved in the biosynthesis of multiple low-molecular-weight thiols (cysteine, homocysteine, and bacillithiol), as well as the thioredoxin system. Phenotypic analysis of gene replacement mutants indicated that Oah contributes to Hg resistance under sulfur-limiting conditions, and strains lacking bacillithiol and/or thioredoxins are more sensitive to Hg(II) than the wild type. Growth in the presence of either a thiol-oxidizing agent or a thiol-alkylating agent increased sensitivity to Hg(II). Furthermore, exposure to 3 μM Hg(II) consumed all intracellular reduced bacillithiol and cysteine. Database searches indicate that oah2 is present in all Thermus sp. mer operons. The presence of a thiol-related gene was also detected in some alphaproteobacterial mer operons, in which a glutathione reductase gene was present, supporting the role of thiols in Hg(II) detoxification. These results have led to a working model in which LMW thiols act as Hg(II)-buffering agents while Hg is reduced by MerA.IMPORTANCE The survival of microorganisms in the presence of toxic metals is central to life's sustainability. The affinity of thiol groups for toxic heavy metals drives microbe-metal interactions and modulates metal toxicity. Mercury detoxification (mer) genes likely originated early in microbial evolution in geothermal environments. Little is known about how mer systems interact with cellular thiol systems. Thermus spp. possess a simple mer operon in which a low-molecular-weight thiol biosynthesis gene is present, along with merR and merA In this study, we present experimental evidence for the role of thiol systems in mercury resistance. Our data suggest that, in T. thermophilus, thiolated compounds may function side by side with mer genes to detoxify mercury. Thus, thiol systems function in consort with mer-mediated resistance to mercury, suggesting exciting new questions for future research.
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Kim YO, Bae HJ, Cho E, Kang H. Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells. FRONTIERS IN PLANT SCIENCE 2017; 8:683. [PMID: 28507557 PMCID: PMC5410599 DOI: 10.3389/fpls.2017.00683] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 04/13/2017] [Indexed: 05/07/2023]
Abstract
Despite the increasing understanding of the crucial roles of glutathione (GSH) in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg) tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd), copper (Cu), or zinc (Zn), whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants.
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Affiliation(s)
- Yeon-Ok Kim
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National UniversityGwangju, South Korea
- *Correspondence: Hunseung Kang, Yeon-Ok Kim,
| | - Hyeun-Jong Bae
- Department of Bioenergy Science and Technology, College of Agriculture and Life Sciences, Chonnam National UniversityGwangju, South Korea
| | - Eunjin Cho
- Department of Bioenergy Science and Technology, College of Agriculture and Life Sciences, Chonnam National UniversityGwangju, South Korea
| | - Hunseung Kang
- Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National UniversityGwangju, South Korea
- *Correspondence: Hunseung Kang, Yeon-Ok Kim,
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Thapa G, Das D, Gunupuru LR. Expression of Echmr gene from Eichhornia offers multiple stress tolerance to Cd sensitive Escherichia coli Δgsh mutants. Biochem Biophys Res Commun 2016; 478:101-109. [PMID: 27457806 DOI: 10.1016/j.bbrc.2016.07.086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 07/19/2016] [Indexed: 12/26/2022]
Abstract
The detoxification of heavy metals frequently involves conjugation to glutathione prior to compartmentalization and eflux in higher plants. We have expressed a heavy metal stress responsive (Echmr) gene from water hyacinth, which conferred tolerance to Cd sensitive Escherichia coli Δgsh mutants against heavy metals and abiotic stresses. The recombinant E. coli Δgsh mutant cells showed better growth recovery and survival than control cells under Cd (200 μM), Pb(200 μM), heat shock (50 °C), cold stress at 4 °C for 4 h, and UV-B (20 min) exposure. The enhanced expression of Echmr gene revealed by northern analysis during above stresses further advocates its role in multi-stress tolerance. Heterologous expression of EcHMR from Eichhornia rescued Cd(2+) sensitive E. coli mutants from Cd(2+) toxicity and induced better recovery post abiotic stresses. This may suggests a possible role of Echmr in Cd(II) and desiccation tolerance in plants for enhanced stress response.
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Affiliation(s)
- G Thapa
- Department of Biotechnology, Indian Institute of Technology Guwahati, North Guwahati 781039, Assam, India; Earth Institute, Molecular Plant Pathogen Interactions Group, School of Biology and Environmental Science, University College Dublin, Ireland.
| | - D Das
- Utrecht University, The Netherlands
| | - L R Gunupuru
- Earth Institute, Molecular Plant Pathogen Interactions Group, School of Biology and Environmental Science, University College Dublin, Ireland
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LaVoie SP, Mapolelo DT, Cowart DM, Polacco BJ, Johnson MK, Scott RA, Miller SM, Summers AO. Organic and inorganic mercurials have distinct effects on cellular thiols, metal homeostasis, and Fe-binding proteins in Escherichia coli. J Biol Inorg Chem 2015; 20:1239-51. [PMID: 26498643 PMCID: PMC4749482 DOI: 10.1007/s00775-015-1303-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/08/2015] [Indexed: 02/07/2023]
Abstract
The protean chemical properties of the toxic metal mercury (Hg) have made it attractive in diverse applications since antiquity. However, growing public concern has led to an international agreement to decrease its impact on health and the environment. During a recent proteomics study of acute Hg exposure in E. coli, we also examined the effects of inorganic and organic Hg compounds on thiol and metal homeostases. On brief exposure, lower concentrations of divalent inorganic mercury Hg(II) blocked bulk cellular thiols and protein-associated thiols more completely than higher concentrations of monovalent organomercurials, phenylmercuric acetate (PMA) and merthiolate (MT). Cells bound Hg(II) and PMA in excess of their available thiol ligands; X-ray absorption spectroscopy indicated nitrogens as likely additional ligands. The mercurials released protein-bound iron (Fe) more effectively than common organic oxidants and all disturbed the Na(+)/K(+) electrolyte balance, but none provoked efflux of six essential transition metals including Fe. PMA and MT made stable cysteine monothiol adducts in many Fe-binding proteins, but stable Hg(II) adducts were only seen in CysXxx(n)Cys peptides. We conclude that on acute exposure: (a) the distinct effects of mercurials on thiol and Fe homeostases reflected their different uptake and valences; (b) their similar effects on essential metal and electrolyte homeostases reflected the energy dependence of these processes; and (c) peptide phenylmercury-adducts were more stable or detectable in mass spectrometry than Hg(II)-adducts. These first in vivo observations in a well-defined model organism reveal differences upon acute exposure to inorganic and organic mercurials that may underlie their distinct toxicology.
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Affiliation(s)
- Stephen P LaVoie
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA
| | - Daphne T Mapolelo
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
- Department of Chemistry, University of Botswana, P.O. Box 00704, Gaborone, Botswana
| | - Darin M Cowart
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
| | - Benjamin J Polacco
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Michael K Johnson
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
| | - Robert A Scott
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
| | - Susan M Miller
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Anne O Summers
- Department of Microbiology, University of Georgia, Athens, GA, 30602, USA.
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García-Beltrán O, Rodríguez A, Trujillo A, Cañete A, Aguirre P, Gallego-Quintero S, Nuñez MT, Aliaga ME. Synthesis and characterization of a novel fluorescent and colorimetric probe for the detection of mercury (II) even in the presence of relevant biothiols. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Ding X, Hua Y, Chen Y, Zhang C, Kong X. Heavy metal complexation of thiol-containing peptides from soy glycinin hydrolysates. Int J Mol Sci 2015; 16:8040-58. [PMID: 25867477 PMCID: PMC4425066 DOI: 10.3390/ijms16048040] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/03/2015] [Accepted: 04/07/2015] [Indexed: 11/24/2022] Open
Abstract
Many thiol-containing molecules show heavy metal complexation ability and are used as antidotes. In this study, the potential function associated with thiol-containing peptides (TCPs) from soy protein hydrolysates as natural detoxicants for heavy metals is reported. TCPs enriched by Thiopropyl-Sepharose 6B covalent chromatography had different molecular weight distributions as well as different numbers of proton dissociable groups, depending on the proteases and degree of hydrolysis. The major contribution of sulfhydryl groups was confirmed by the largest pH decrease between 8.0 and 8.5 of the pH titration curves. The complexation of TCPs with heavy metalswas evaluated by stability constants (βn) of TCP-metal complexes whose stoichiometry was found to be 1:1 (ML) and 1:2 (ML2). TCPs from degree of hydrolysis of 25% hydrolysates gave high affinities towards Hg2+, Cd2+, and Pb2+ (giving similar or even bigger lgβ values than that of glutathione). A significantly positive correlation was found between the logarithm of stability constants for ML2 (lgβ2) and the sulfhydryl group content. Molecular weight distribution of TCPs affected the complexation with Pb2+ notably more than Hg2+ and Cd2+. These results suggest that soy TCPs have the potential to be used in the formulation of functional foods to counteract heavy metal accumulation in humans.
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Affiliation(s)
- Xiuzhen Ding
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Yufei Hua
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Yeming Chen
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Caimeng Zhang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Xiangzhen Kong
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
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Tinkov AA, Ajsuvakova OP, Skalnaya MG, Popova EV, Sinitskii AI, Nemereshina ON, Gatiatulina ER, Nikonorov AA, Skalny AV. Mercury and metabolic syndrome: a review of experimental and clinical observations. Biometals 2015; 28:231-54. [DOI: 10.1007/s10534-015-9823-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/15/2015] [Indexed: 12/16/2022]
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Nieh CC, Tseng WL. Thymine-based molecular beacon for sensing adenosine based on the inhibition of S-adenosylhomocysteine hydrolase activity. Biosens Bioelectron 2014; 61:404-9. [DOI: 10.1016/j.bios.2014.05.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 01/23/2023]
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Singh B, Das RS, Banerjee R, Mukhopadhyay S. Uncatalyzed and copper(II) catalyzed oxidation of glutathione by Co(III)2 bound superoxide complex. Inorganica Chim Acta 2014. [DOI: 10.1016/j.ica.2014.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lotfi Zadeh Zhad HR, Lai RY. A Hg(ii)-mediated “signal-on” electrochemical glutathione sensor. Chem Commun (Camb) 2014; 50:8385-7. [DOI: 10.1039/c4cc03329a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Zhao J, Chen C, Zhang L, Jiang J, Shen G, Yu R. A Hg(2+)-mediated label-free fluorescent sensing strategy based on G-quadruplex formation for selective detection of glutathione and cysteine. Analyst 2013; 138:1713-8. [PMID: 23377184 DOI: 10.1039/c3an36657j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A novel label-free fluorescent strategy for the detection of glutathione (GSH) and cysteine (Cys) is presented. The system consists of two single stranded DNA (ssDNA) with thymine-thymine (T-T) mismatches and used Hg(2+) as a mediator, and N-methyl mesoporphyrin IX (NMM) as the signal reporter. The assay is based on the competitive reaction of Hg(2+) with GSH/Cys and T-T mismatched double stranded DNA (dsDNA). In the absence of the target, two ssDNA containing T-T mismatches react with Hg(2+) to form a T-Hg(2+)-T dsDNA structure in the solution, which hampers the formation of a G-quadruplex structure. However, in the presence of the target, GSH/Cys reacts with Hg(2+) to keep DNA probes in a free single state, resulting in the effective formation of a G-quadruplex structure of the DNA probe (GP). Subsequently, due to the strong interaction between the G-quadruplex structure and NMM, fluorescence was greatly enhanced. This fluorescence strategy does not require any chemical modification, making the assay convenient and cost-effective. This method exhibited a linear relationship between peak fluorescence intensity and concentration of GSH in the range of 10-400 nM with a limit of detection (LOD) of 9.6 nM. A linear range for Cys detection was obtained in the concentration range of 10-500 nM with an LOD of 10 nM. Moreover, the proposed method worked well for the analysis of complex biological samples.
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Affiliation(s)
- Jingjin Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China
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García-Beltrán O, Mena N, Berríos TA, Castro EA, Cassels BK, Núñez MT, Aliaga ME. A selective fluorescent probe for the detection of mercury (II) in aqueous media and its applications in living cells. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.09.111] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lin X, Brooks J, Bronson M, Ngu-Schwemlein M. Evaluation of the association of mercury(II) with some dicysteinyl tripeptides. Bioorg Chem 2012; 44:8-18. [PMID: 22784828 PMCID: PMC3448868 DOI: 10.1016/j.bioorg.2012.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 06/07/2012] [Accepted: 06/12/2012] [Indexed: 01/04/2023]
Abstract
The present study was undertaken to gain insight into the associations of mercury(II) with dicysteinyl tripeptides in buffered media at pH 7.4. We investigated the effects of increasing the distance between cysteinyl residues on mercury(II) associations and complex formations. The peptide-mercury(II) formation constants and their associated thermodynamic parameters in 3-(N-morpholino)propanesulfonic acid (MOPS) buffered solutions were evaluated by isothermal titration calorimetry. Complexes formed in different relative ratios of mercury(II) to cysteinyl peptides in ammonium formate buffered solutions were characterized by LTQ Orbitrap mass spectrometry. The results from these studies show that n-alkyl dicysteinyl peptides (CP 1-4), and an aryl dicysteinyl peptide (CP 5) can serve as effective "double anchors" to accommodate the coordination sites of mercury(II) to form predominantly one-to-one Hg(peptide) complexes. The aryl dicysteinyl peptide (CP 5) also forms the two-to-two Hg(2)(peptide)(2) complex. In the presence of excess peptide, Hg(peptide)(2) complexes are also detected. Notably, increasing the distance between the ligating groups or "anchor points" in CP 1-5 does not significantly affect their affinity for mercury(II). However, the enthalpy change (ΔH) values (ΔH(1) ~ -91 kJ mol(-1) and ΔH(2) ~ -66 kJ mol(-1)) for complex formation between CP 4 and 5 with mercury(II) are about one and a half times larger than the related values for CP 1, 2 and 3 (ΔH(1) ~ -66 kJ mol(-1) and ΔH(2) ~ 46 kJ mol(-1)). The corresponding entropy change (ΔS) values (ΔS(1) ~ -129 J K(-1) mol(-1) and ΔS(2) ~ -116 J K(-1) mol(-1)) of the structurally larger dicysteinyl peptides CP 4 and 5 are less entropically favorable than for CP 1, 2 and 3 (ΔS(1) ~ -48 J K(-1) mol(-1) and ΔS(2) ~ -44 J K(-1) mol(-1)). Generally, these associations result in a decrease in entropy, indicating that these peptide-mercury complexes potentially form highly ordered structures. The results from this study show that dicysteinyl tripeptides are effective in binding mercury(II) and they are promising motifs for the design of multi-cysteinyl peptides for binding more than one mercury(II) ion per peptide.
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Affiliation(s)
- Xiuli Lin
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Jeremy Brooks
- Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA
| | - Matthew Bronson
- Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA
| | - Maria Ngu-Schwemlein
- Department of Chemistry, Winston-Salem State University, Winston-Salem, NC 27110, USA
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Yang J, Zhang WH, Hu YP, Yu JS. Aqueous synthesis and characterization of glutathione-stabilized β-HgS nanocrystals with near-infrared photoluminescence. J Colloid Interface Sci 2012; 379:8-13. [DOI: 10.1016/j.jcis.2012.04.057] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 03/19/2012] [Accepted: 04/14/2012] [Indexed: 12/01/2022]
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Shankar R, Kolandaivel P, Senthil kumar L. Coordination and binding properties of zwitterionic glutathione with transition metal cations. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2012.01.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Hochreuther S, van Eldik R. Reactivity of a cytostatic active N,N-donor-containing dinuclear Pt(II) complex with biological relevant nucleophiles. Inorg Chem 2012; 51:3025-38. [PMID: 22356171 DOI: 10.1021/ic202351r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A dinuclear platinum(II) complex that was recently investigated in our group was tested for its cytostatic activity and found to be active against HeLa S3 cells. The complex consists of a bidentate N,N-donor chelating ligand system in which the two platinum centers are connected by an aliphatic chain of 10 methylene groups. The complex [Pt(2)(N(1),N(10)-bis(2-pyridylmethyl)-1,10-decanediamine)(OH(2))(4)](4+) (10NNpy) is of further special interest, since only little is known about the substitution behavior of such dinuclear platinum complexes that contain a bidentate coordination sphere. The complex was investigated using different biologically relevant nucleophiles, such as thiourea (tu), L-methionine (L-Met), glutathione (GSH), and guanine-5'-monophosphate (5'-GMP), at two different pH values (2 and 7.4). The substitution of coordinated water by these nucleophiles was studied under pseudo-first-order conditions as a function of nucleophile concentration, temperature, and pressure, using stopped-flow techniques and UV-vis spectroscopy. The reactivity of 10NNpy with the selected nucleophiles was found to be tu ≫ 5'-GMP > L-Met > GSH at pH 2 and GSH > tu > L-Met at pH 7.4. The results for the dinuclear 10NNpy complex were compared to those for the corresponding mononuclear reference complex [Pt(aminomethylpyridine)(OH(2))(2)](2+), Pt(amp), studied before in our group, by which the effect of the addition of an aliphatic chain, an increase in the overall charge, and a shift in the pK(a) values of the coordinated water ligands could be investigated. The reactivity order for Pt(amp) was found to be tu > GSH > L-Met at pH 7.4.
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Affiliation(s)
- Stephanie Hochreuther
- Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstr. 1, 91058 Erlangen, Germany
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Ma B, Zeng F, Li X, Wu S. A facile approach for sensitive, reversible and ratiometric detection of biothiols based on thymine-mediated excimer–monomer transformation. Chem Commun (Camb) 2012; 48:6007-9. [DOI: 10.1039/c2cc32064a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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34
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Xu H, Wang Y, Huang X, Li Y, Zhang H, Zhong X. Hg2+-mediated aggregation of gold nanoparticles for colorimetric screening of biothiols. Analyst 2012; 137:924-31. [DOI: 10.1039/c2an15926k] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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35
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Neupane KP, Pecoraro VL. Pb-207 NMR spectroscopy reveals that Pb(II) coordinates with glutathione (GSH) and tris cysteine zinc finger proteins in a PbS3 coordination environment. J Inorg Biochem 2011; 105:1030-4. [PMID: 21625408 DOI: 10.1016/j.jinorgbio.2011.04.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
207Pb NMR spectroscopy can be used to monitor the binding of Pb(II) to thiol rich biological small molecules such as glutathione and to zinc finger proteins. The UV/visible (UV/Vis) absorption band centered at 334 nM and the observed 207Pb-signal in 207Pb NMR (δ~5750 ppm) indicate that glutathione binds Pb(II) in a trigonal pyramidal geometry (PbS3) at pH 7.5 or higher with a 1:3 molar ratio of Pb(II) to GSH. While previous studies using UV/Vis and extended X-ray absorption fine structure (EXAFS) spectroscopy were interpreted to show that the zinc binding domain from HIV nucleocapsid protein (HIV-CCHC) binds Pb(II) in a single PbS3 environment, the more sensitive 207Pb NMR spectra (at pH 7.0, 1:1 molar ratio) provide compelling evidence for the presence of two PbS3 structures (δ=5790 and 5744 ppm), one of which is more stable at high temperatures. It has previously been proposed that the HIV-CCHH peptide does not fold properly to afford a PbS2N motif, because histidine does not bind to Pb(II). These predictions are confirmed by the present studies. These results demonstrate the applicability of 207Pb NMR to biomolecular structure determination in proteins with cysteine binding sites for the first time.
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Affiliation(s)
- Kosh P Neupane
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
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Xu H, Gao S, Liu Q, Pan D, Wang L, Ren S, Ding M, Chen J, Liu G. A highly sensitive and selective competition assay for the detection of cysteine using mercury-specific DNA, Hg and Sybr Green I. SENSORS 2011; 11:10187-96. [PMID: 22346638 PMCID: PMC3274280 DOI: 10.3390/s111110187] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 10/18/2011] [Accepted: 10/23/2011] [Indexed: 11/16/2022]
Abstract
We here report a rapid, sensitive, selective and label-free fluorescence detection method for cysteine (Cys). The conformation of mercury-specific DNA (MSD) changes from a random coil form to a hairpin structure in the presence of Hg2+ due to the formation of a thymine-Hg2+ -thymine (T-Hg2+ -T) complex. Cys can selectively coordinate with Hg2+ and extract it from the thymine-Hg2+ -thymine complex. The hairpin structure dehybridizes and the fluorescence intensity of Sybr Green I (SG) decreases upon addition of Cys because SG efficiently discriminates mercury-specific DNA and mercury-specific DNA/Hg2+ complex. The detection can be finished within 5 min with high sensitivity and selectivity. In addition, we can obtain variable dynamic ranges for Cys by changing the concentration of MSD/Hg2+.
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Affiliation(s)
- Hui Xu
- School of Chemistry and Material Sciences, Ludong University, Yantai 264025, China; E-Mails: (S.G.); (Q.L.)
- Authors to whom correspondence should be addressed; E-Mail: (H.X.); Tel.: 86-535-667-2176 (H.X.); Fax: 86-535-669-7667 (H.X.); E-Mail: (G.L.); Tel.: 86-21-3883-9800-35232 (G.L.); Fax: 86-21-5079-8552 (G.L.)
| | - Shuli Gao
- School of Chemistry and Material Sciences, Ludong University, Yantai 264025, China; E-Mails: (S.G.); (Q.L.)
| | - Quanwen Liu
- School of Chemistry and Material Sciences, Ludong University, Yantai 264025, China; E-Mails: (S.G.); (Q.L.)
| | - Dun Pan
- Laboratory of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; E-Mails: (D.P.); (L.W.)
| | - Lihua Wang
- Laboratory of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China; E-Mails: (D.P.); (L.W.)
| | - Shuzhen Ren
- Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China; E-Mails: (S.R.); (M.D.); (J.C.)
| | - Min Ding
- Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China; E-Mails: (S.R.); (M.D.); (J.C.)
| | - Jingwen Chen
- Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China; E-Mails: (S.R.); (M.D.); (J.C.)
| | - Gang Liu
- Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China; E-Mails: (S.R.); (M.D.); (J.C.)
- Authors to whom correspondence should be addressed; E-Mail: (H.X.); Tel.: 86-535-667-2176 (H.X.); Fax: 86-535-669-7667 (H.X.); E-Mail: (G.L.); Tel.: 86-21-3883-9800-35232 (G.L.); Fax: 86-21-5079-8552 (G.L.)
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37
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Quantum chemical studies on the role of water microsolvation in interactions between group 12 metal species (Hg2+, Cd2+, and Zn2+) and neutral and deprotonated cysteines. Theor Chem Acc 2011. [DOI: 10.1007/s00214-011-0975-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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38
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Xu H, Hepel M. “Molecular Beacon”-Based Fluorescent Assay for Selective Detection of Glutathione and Cysteine. Anal Chem 2011; 83:813-9. [DOI: 10.1021/ac102850y] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Hui Xu
- Department of Chemistry, State University of New York at Potsdam, Potsdam, New York 13676, United States
| | - Maria Hepel
- Department of Chemistry, State University of New York at Potsdam, Potsdam, New York 13676, United States
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39
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Mercuric ions inhibit mitogen-activated protein kinase dephosphorylation by inducing reactive oxygen species. Toxicol Appl Pharmacol 2011; 250:78-86. [DOI: 10.1016/j.taap.2010.10.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 09/19/2010] [Accepted: 10/06/2010] [Indexed: 12/17/2022]
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Mah V, Jalilehvand F. Glutathione complex formation with mercury(II) in aqueous solution at physiological pH. Chem Res Toxicol 2010; 23:1815-23. [PMID: 21073204 DOI: 10.1021/tx100260e] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mercury(II) complexes formed in neutral aqueous solution with glutathione (GSH, here denoted AH(3) in its triprotonated form) were studied using Hg L(III)-edge extended X-ray absorption fine structure (EXAFS) and (199)Hg NMR spectroscopy, complemented with electrospray ionization mass spectrometric (ESI-MS) analyses. The [Hg(AH)(2)](2-) complex, with the Hg-S bond distances at 2.325 ± 0.01 Å in linear S-Hg-S coordination, and the (199)Hg NMR chemical shift at -984 ppm, dominates except at high excess of glutathione. In a series of solutions with C(Hg(II)) ∼17 mM and GSH/Hg(II) mole ratios rising from 2.4 to 11.8, the gradually increasing mean Hg-S bond distance corresponds to an increasing amount of the [Hg(AH)(3)](4-) complex. ESI-MS peaks appear at -m/z values of 1208 and 1230 corresponding to the [Na(4)Hg(AH)(2)(A)](-) and [Na(5)Hg(AH)(A)(2)](-) species, respectively. In another series of solutions at pH 7.0 with C(Hg(II)) ∼50 mM and GSH/Hg(II) ratios from 2.0 to 10.0, the Hg L(III)-edge EXAFS and (199)Hg NMR spectra show that at high excess of glutathione (∼0.35 M) about ∼70% of the total mercury(II) concentration is present as the [Hg(AH)(3)](4-) complex, with the average Hg-S bond distance 2.42 ± 0.02 Å in trigonal HgS(3) coordination. The proportions of HgS(n) species, n = 2, 3, and 4, quantified by fitting linear combinations of model EXAFS oscillations to the experimental EXAFS data in our present and previous studies were used to obtain stability constants for the [Hg(AH)(3)](4-) complex and also for the [Hg(A)(4)](10-) complex that is present at high pH. For Hg(II) in low concentration at physiological conditions (pH 7.4, C(GSH) = 2.2 mM), the relative amounts of the HgS(2) species [Hg(AH)(2)](2-), [Hg(AH)(A)](3-), and the HgS(3) complex [Hg(AH)(3)](4-) were calculated to be 95:2:3. Our results are not consistent with the formation of dimeric Hg(II)-GSH complexes proposed in a recent EXAFS study.
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Affiliation(s)
- Vicky Mah
- Department of Chemistry, University of Calgary, Calgary, AB, Canada
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41
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Moingt M, Bressac M, Bélanger D, Amyot M. Role of ultra-violet radiation, mercury and copper on the stability of dissolved glutathione in natural and artificial freshwater and saltwater. CHEMOSPHERE 2010; 80:1314-1320. [PMID: 20598342 DOI: 10.1016/j.chemosphere.2010.06.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 06/09/2010] [Accepted: 06/10/2010] [Indexed: 05/29/2023]
Abstract
The behavior and stability of dissolved reduced glutathione (GSH), an environmental antioxidant and metal transporter, is poorly known in natural waters. Glutathione oxidation rates were determined in both fresh- and brackish waters artificially submitted to different radiation wavebands. Photo-oxidation of GSH followed pseudo-first order kinetics, with half-lives ranging from 4 to 30h in natural freshwater, and from 1.6 to 7h in saltwater, with generally shorter persistence in UV-irradiated surface waters than in dark treatments. Chloride was shown to indirectly promote GSH photo-oxidation, probably through its role in the formation of radicals. The addition of Cu(II) to synthetic waters resulted in the rapid oxidation of GSH. The addition of Hg(II), a metal with strong affinity for thiols, protected GSH from oxidation by Cu(II) in the dark, but not under UV radiation. We conclude that UV-induced photo-oxidation is a key process altering the fate of GSH in natural waters. Also, the formation of stable GSH-Hg complexes could increase the bioavailability of Hg towards microorganisms in aquatic systems.
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Affiliation(s)
- Matthieu Moingt
- Groupe de Recherche Inter-Universitaire en Limnologie, Département de Sciences Biologiques, Université de Montréal, CP 6128, Succursale Centre-Ville, Pavillon Marie-Victorin, Montréal, Québec, Canada
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42
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Binding of Hg2+ by Cys, Cys-Gly and reduced glutathione: Study by differential pulse voltammetry on rotating Au-disk electrode, electrospray ionization mass-spectrometry and isothermal titration calorimetry. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2010.03.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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43
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Zheng W, Hintelmann H. Isotope Fractionation of Mercury during Its Photochemical Reduction by Low-Molecular-Weight Organic Compounds. J Phys Chem A 2010; 114:4246-53. [PMID: 20218588 DOI: 10.1021/jp9111348] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wang Zheng
- Environmental and Life Sciences Program, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9J 7B8, Canada
| | - Holger Hintelmann
- Environmental and Life Sciences Program, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9J 7B8, Canada
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Munteanu G, Dempsey E, McCormac T. Ultrafast voltammetric determination of biological thiols on the copper nanodoped mercury monolayer carbon fiber electrode. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2009.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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45
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Mah V, Jalilehvand F. Cadmium(II) complex formation with glutathione. J Biol Inorg Chem 2009; 15:441-58. [PMID: 20035360 DOI: 10.1007/s00775-009-0616-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 12/04/2009] [Indexed: 11/24/2022]
Abstract
Complex formation between heavy metal ions and glutathione (GSH) is considered as the initial step in many detoxification processes in living organisms. In this study the structure and coordination between the cadmium(II) ion and GSH were investigated in aqueous solutions (pH 7.5 and 11.0) and in the solid state, using a combination of spectroscopic techniques. The similarity of the Cd K-edge and L(3)-edge X-ray absorption spectra of the solid compound [Cd(GS)(GSH)]ClO(4).3H(2)O, precipitating at pH 3.0, with the previously studied cysteine compound {Cd(HCys)(2).H(2)O}(2).H(3)O(+).ClO(4) (-) corresponds to Cd(S-GS)(3)O (dominating) and Cd(S-GS)(4) four-coordination within oligomeric complexes with mean bond distances of 2.51 +/- 0.02 A for Cd-S and 2.24 +/- 0.04 A for Cd-O. For cadmium(II) solutions (C (Cd(II)) approximately 0.05 M) at pH 7.5 with moderate excess of GSH (C (GSH)/C (Cd(II)) = 3.0-5.0), a mix of Cd(S-GS)(3)O (dominating) and Cd(S-GS)(4) species is consistent with the broad (113)Cd NMR resonances in the range 632-658 ppm. In alkaline solutions (pH 11.0 and C (GSH)/C (Cd(II)) = 2.0 or 3.0), two distinct peaks at 322 and 674 ppm are obtained. The first peak indicates six-coordinated mononuclear and dinuclear complexes with CdS(2)N(2)(N/O)(2) and CdSN(3)O(2) coordination in fast exchange, whereas the second corresponds to Cd(S-GS)(4) sites. At high ligand excess the tetrathiolate complex, Cd(S-GS)(4), characterized by a sharp delta((113)Cd) NMR signal at 677 ppm, predominates. The average Cd-S distance, obtained from the X-ray absorption spectra, varied within a narrow range, 2.49-2.53 A, for all solutions (pH 7.5 and 11.0) regardless of the coordination geometry.
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Affiliation(s)
- Vicky Mah
- Department of Chemistry, University of Calgary, Calgary, AB, T2N 1N4, Canada
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46
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Determination of methylmercury and inorganic mercury by coupling short-column ion chromatographic separation, on-line photocatalyst-assisted vapor generation, and inductively coupled plasma mass spectrometry. J Chromatogr A 2009; 1216:8933-8. [DOI: 10.1016/j.chroma.2009.10.061] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 10/19/2009] [Accepted: 10/23/2009] [Indexed: 11/22/2022]
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47
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Schiraldi M, Monestier M. How can a chemical element elicit complex immunopathology? Lessons from mercury-induced autoimmunity. Trends Immunol 2009; 30:502-9. [PMID: 19709928 DOI: 10.1016/j.it.2009.07.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 07/15/2009] [Accepted: 07/27/2009] [Indexed: 01/09/2023]
Abstract
Although most autoimmune diseases develop without a manifest cause, epidemiological studies indicate that external factors play an important role in triggering or aggravating autoimmune processes in genetically predisposed individuals. Nevertheless, most autoimmune disease-promoting environmental agents are unknown because their relationships to immune function are not understood. Thus, the study of animal models of chemically-induced autoimmunity should shed light on the pathways involved and allow us to identify these agents. The rodent model of heavy metal-induced autoimmunity is one of the most intriguing experimental systems available to address such questions. Although the ultimate pathophysiology of this model remains mysterious, recent studies have started to elucidate the mechanisms by which heavy metal exposure leads to immune activation and loss of self-tolerance.
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Affiliation(s)
- Michael Schiraldi
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania, 19140, United States
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48
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Lucu C, Dupcić-Radić I, Tomsić S. Methyl mercury inhibits short-circuit current and Cl- influx across isolated epipodite of European lobster (Homarus gammarus). Comp Biochem Physiol C Toxicol Pharmacol 2009; 149:476-80. [PMID: 19038364 DOI: 10.1016/j.cbpc.2008.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2008] [Revised: 11/01/2008] [Accepted: 11/02/2008] [Indexed: 11/30/2022]
Abstract
The effect of methyl mercuric chloride (MeHg) on short-circuit current (I(SC)) was studied in the isolated perfused epipodite preparation from the branchial chamber of European lobster (Homarus gammarus) acclimated to dilute seawater. When applied at the apical surface, 0.2, 1.0 and 3.0 microM MeHg depressed I(SC) by a 26%, 81% and 98%, respectively. The half-maximal inhibitory concentration (IC(50)) of apically applied MeHg was 0.6 microM. Basolaterally added MeHg (3.0 microM) had no effect on I(SC), whereas addition of the specific Na(+),K(+)-ATPase inhibitor ouabain (1.5 mM) reduced I(SC) by approximately 90%. Ouabain effects were reversible, and I(SC) fully recovered upon removal of ouabain. The MeHg-induced block of I(SC) was partially reversed by the reducing agent, 1,4-dithiothreitol, suggesting that the formation of S-Hg-S bridges is important in the inhibitory mechanism. A significant reduction of I(SC) and conductance occurred when low Na(+) and Cl(-) salines were substituted. Furthermore, in the low Na(+) saline, J(Cl)(A-->B) fluxes were reduced by about 50%. In the highly conductive epipodite epithelium, coupling of Na(+) and Cl(-) fluxes was suggested. The effects of MeHg on I(SC) in the lobster epipodite are attributed to inhibition of an apical Cl(-) influx.
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Affiliation(s)
- Cedomil Lucu
- University of Dubrovnik, Department of Aquaculture, Dubrovnik, Croatia.
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49
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Chekmeneva E, Díaz-Cruz JM, Ariño C, Esteban M. A novel differential pulse voltammetric method on rotating Au-disk electrode for the study of Hg2+ binding. J Electroanal Chem (Lausanne) 2009. [DOI: 10.1016/j.jelechem.2009.02.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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50
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Abstract
The heavy metal mercury is ubiquitously distributed in the environment resulting in permanent low-level exposure in human populations. Mercury can be encountered in three main chemical forms (elemental, inorganic, and organic) which can affect the immune system in different ways. In this review, we describe the effects of these various forms of mercury exposure on immune cells in humans and animals. In genetically susceptible mice or rats, subtoxic doses of mercury induce the production of highly specific autoantibodies as well as a generalized activation of the immune system. We review studies performed in this model and discuss their implications for the role of environmental chemicals in human autoimmunity.
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Affiliation(s)
- Jaya Vas
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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