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Breaking the dogma: PCB-derived semiquinone free radicals do not form covalent adducts with DNA, GSH, and amino acids

  • PCBs: Exposures, Effects, Remediation and Regulation with special reference to PCBs in Schools
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Abstract

Covalent bond formations of free radical metabolites with biomolecules like DNA and proteins are thought to constitute a major mechanism of toxicity and carcinogenesis. Glutathione (GSH) is generally accepted as a radical scavenger protecting the cell. In the present study, we investigated a semiquinone radical (SQ●-) metabolite of the semivolatile 4-chlorobiphenyl, using electron paramagnetic resonance spectroscopy, and oxygen consumption. Proton nuclear magnetic resonance (1H NMR) and liquid chromatography–mass spectrometry (LC-MS) were also employed to elucidate the radical interaction with DNA, amino acids, and GSH. We found that DNA and oligonucleotides stabilized SQ●- by electron delocalization in the π-stacking system, resulting in persistent radical intercalated, rather than forming a covalent bond with SQ●-. This finding was strongly supported by the semiempirical calculation of the semioccupied molecular orbital and the linear combination of the atomic orbitals, indicating 9.8 kcal mol−1 energy gain. The insertion of SQ●- into the DNA strand may result in DNA strand breaks and interruption of DNA replication process or even activate radical mediated secondary reactions. The presence of amino acids resulted in a decrease of the electron paramagnetic resonance (EPR) signal of SQ●- and correlated with their isoelectric points. The pH shifts the equilibrium of the dianions of hydroquinone and influenced indirectly the formation of SQ●-. Similar findings were observed with GSH and Cys. GSH and Cys functioned as indirect radical scavengers; their activities depend on their chemical equilibria with the corresponding quinones, and their further reaction via Michael addition. The generally accepted role of GSH as radical scavenger in biological systems should be reconsidered based upon these findings, questioning the generally accepted view of radical interaction of semiquinones with biologically active compounds, like DNA, amino acids, proteins, and radical scavengers like GSH.

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Notes

  1. http://www.rcsb.org/pdb/explore/explore.do?structureId=3OOR

Abbreviations

4-CB-2’,5’-Q:

4-Chlorobiphenyl-2’,5’-benzoquinone

4-CB-2’,5’-H2Q:

4-Chlorobiphenyl-2’,5’-hydroquinone

4-CB-2’,5’-SQ•– :

4-Chlorobiphenyl-2’,5’-semiquinone radical

AA:

Arachidonic acid

DMSO:

Dimethyl sulfoxide

EPR:

Electron paramagnetic resonance

GSH:

Glutathione, reduced form

H2Q:

Hydroquinones

hPGHS-2:

Human recombinant prostaglandin H synthase-2

KAA:

Potassium arachidonate

LCAO:

Linear combination of the atomic orbitals

PCBs:

Polychlorinated biphenyls

Q:

Quinones

ROS:

Reactive oxygen species

SOMO:

Semioccupied molecular orbital

SQ•– :

Semiquinone free radicals

References

  • Amaro AR, Oakley GG, Bauer U, Spielmann HP, Robertson LW (1996) Metabolic activation of PCBs to quinones: reactivity toward nitrogen and sulfur nucleophiles and influence of superoxide dismutase. Chem Res Toxicol 9(3):623–629

    Article  CAS  Google Scholar 

  • Arif JM, Lehmler HJ, Robertson LW, Gupta RC (2003) Interaction of benzoquinone- and hydroquinone-derivatives of lower chlorinated biphenyls with DNA and nucleotides in vitro. Chem Biol Interact 142(3):307–316

    Article  CAS  Google Scholar 

  • Blanksby SJ, Ellison GB (2003) Bond dissociation energies of organic molecules. Acc Chem Res 36(4):255–263

    Article  CAS  Google Scholar 

  • Bolton JL, Thatcher GR (2008) Potential mechanisms of estrogen quinone carcinogenesis. Chem Res Toxicol 21(1):93–101

    Article  Google Scholar 

  • Bolton JL, Trush MA, Penning TM, Dryhurst G, Monks TJ (2000) Role of quinones in toxicology. Chem Res Toxicol 13(3):135–160

    Article  CAS  Google Scholar 

  • Buettner GR (1993) The pecking order of free radicals and antioxidants: lipid peroxidation, alpha-tocopherol, and ascorbate. Arch Biochem Biophys 300(2):535–543

    Article  CAS  Google Scholar 

  • Davis BK, Beach JK, Wade MJ, Klein AK, Hock K (2002) Risk Assessment of Polychlorinated Biphenyls (PCBs) in Indoor Air

  • Dwivedy I, Devanesan P, Cremonesi P, Rogan E, Cavalieri E (1992) Synthesis and characterization of estrogen 2,3- and 3,4-quinones. Comparison of DNA adducts formed by the quinones versus horseradish peroxidase-activated catechol estrogens. Chem Res Toxicol 5(6):828–833

    Article  CAS  Google Scholar 

  • Eling TE, Curtis JF, Harman LS, Mason RP (1986) Oxidation of glutathione to its thiyl free radical metabolite by prostaglandin H synthase. A potential endogenous substrate for the hydroperoxidase. J Biol Chem 261(11):5023–5028

    CAS  Google Scholar 

  • Flowers-Geary L, Bleczinki W, Harvey RG, Penning TM (1996) Cytotoxicity and mutagenicity of polycyclic aromatic hydrocarbon ortho-quinones produced by dihydrodiol dehydrogenase. Chem Biol Interact 99(1-3):55–72

    Article  CAS  Google Scholar 

  • Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE et al (2004) Gaussian 03. Gaussian, Inc., Wallingford, CT

  • Harman D (1962) Role of free radicals in mutation, cancer, aging, and the maintenance of life. Radiat Res 16:753–763

    Article  CAS  Google Scholar 

  • Kalyanaraman B, Premovic PI, Sealy RC (1987) Semiquinone anion radicals from addition of amino acids, peptides, and proteins to quinones derived from oxidation of catechols and catecholamines. An ESR spin stabilization study. J Biol Chem 262(23):11080–11087

    CAS  Google Scholar 

  • Kobayashi T, Narumiya S (2002) Function of prostanoid receptors: studies on knockout mice. Prostaglandins Other Lipid Mediat 68-69:557–573

    Article  CAS  Google Scholar 

  • Lehmann L, Esch HL, Kirby PA, Robertson LW, Ludewig G (2007) 4-monochlorobiphenyl (PCB3) induces mutations in the livers of transgenic Fisher 344 rats. Carcinogenesis 28(2):471–478

    Article  CAS  Google Scholar 

  • Li S, Cooper VR, Thonhauser T, Lundqvist BI, Langreth DC (2009) Stacking interactions and DNA intercalation. J Phys Chem B 113(32):11166–11172

    Article  CAS  Google Scholar 

  • Ludewig G, Lehmann L, Esch H, Robertson LW (2008) Metabolic Activation of PCBs to Carcinogens in Vivo - A Review. Environ Toxicol Pharmacol 25(2):241–246

    Article  CAS  Google Scholar 

  • Mill T, Hendry DG, Richardson H (1980) Free-radical oxidants in natural waters. Science 207(4433):886–887

    Article  CAS  Google Scholar 

  • Morrison H, Di Monte D, Nordenskjold M, Jernstrom B (1985) Induction of cell damage by menadione and benzo(a)pyrene-3,6-quinone in cultures of adult rat hepatocytes and human fibroblasts. Toxicol Lett 28(1):37–47

    Article  CAS  Google Scholar 

  • Myers LS (1982) Free radical damages of nucleic acids and their components. In: Pryor WA (ed) Free Radicals in Biology, vol IV. Academic Press, New York, pp 95–115

    Google Scholar 

  • Nonhebel DC, Walton JC (1974) Free-radical Chemistry. Cambridge University Press, London

    Google Scholar 

  • Oakley GG, Devanaboyina U, Robertson LW, Gupta RC (1996a) Oxidative DNA damage induced by activation of polychlorinated biphenyls (PCBs): implications for PCB-induced oxidative stress in breast cancer. Chem Res Toxicol 9(8):1285–1292

    Article  CAS  Google Scholar 

  • Oakley GG, Robertson LW, Gupta RC (1996b) Analysis of polychlorinated biphenyl-DNA adducts by 32P-postlabeling. Carcinogenesis 17(1):109–114

    Article  CAS  Google Scholar 

  • O'Brien PJ (1991) Molecular mechanisms of quinone cytotoxicity. Chem Biol Interact 80(1):1–41

    Article  Google Scholar 

  • Shen L et al (1998) Alkylation of 2'-deoxynucleosides and DNA by the Premarin metabolite 4-hydroxyequilenin semiquinone radical. Chem Res Toxicol 11(2):94–101

    Article  CAS  Google Scholar 

  • Song Y, Buettner GR (2010) Thermodynamic and kinetic considerations for the reaction of semiquinone radicals to form superoxide and hydrogen peroxide. Free Radic Biol Med 49(6):919–962

    Article  CAS  Google Scholar 

  • Song Y, Wagner BA, Lehmler HJ, Buettner GR (2008) Semiquinone radicals from oxygenated polychlorinated biphenyls: electron paramagnetic resonance studies. Chem Res Toxicol 21(7):1359–1367

    Article  CAS  Google Scholar 

  • Srinivasan A, Lehmler HJ, Robertson LW, Ludewig G (2001) Production of DNA strand breaks in vitro and reactive oxygen species in vitro and in HL-60 cells by PCB metabolites. Toxicol Sci 60(1):92–102

    Article  CAS  Google Scholar 

  • Wangpradit O et al (2009) Oxidation of 4-chlorobiphenyl metabolites to electrophilic species by prostaglandin H synthase. Chem Res Toxicol 22(1):64–71

    Article  CAS  Google Scholar 

  • Wangpradit O et al (2010) Observation of an unusual electronically distorted semiquinone radical of PCB metabolites in the active site of prostaglandin H synthase-2. Chemosphere 81(11):1501–1508

    Article  CAS  Google Scholar 

  • Zettner MA et al (2007) Quinoid metabolites of 4-monochlorobiphenyl induce gene mutations in cultured Chinese hamster v79 cells. Toxicol Sci 100(1):88–98

    Article  CAS  Google Scholar 

  • Zhao S, Narang A, Ding X, Eadon G (2004) Characterization and quantitative analysis of DNA adducts formed from lower chlorinated PCB-derived quinones. Chem Res Toxicol 17(4):502–511

    Article  CAS  Google Scholar 

Download references

Acknowledgments

We would like to thank Brett A. Wagner and Joost van’t Erve, the University of Iowa, for their assistance with EPR and oxygraph measurements. The University of Iowa EPR Facility provided invaluable support. We thank Dr. Lynn M. Teesch, and the high-resolution mass spectrometry facility for HPLC-MS support. This publication was made possible by NIH grant P42 ES 013661 and its training core from the National Institute of Environmental Health Sciences (NIEHS), and by The University of Iowa Environmental Health Sciences Research Center, P30 ES 05605. The project was supported by the Tech For Future fund, an initiative of the Saxion and Windesheim Universities of Applied Sciences and the regional government Overijsel, The Netherlands. The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the funding agencies.

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Authors and Affiliations

  1. Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, 100 Oakdale Campus, Iowa, IA, 52242, USA

    Orarat Wangpradit, Garry R. Buettner, Larry W. Robertson & Gregor Luthe

  2. Department of Occupational and Environmental Health, The University of Iowa, 100 Oakdale Campus, Iowa, IA, 52242, USA

    Orarat Wangpradit & Larry W. Robertson

  3. Department of Chemistry, City College of New York, Convent Avenue at 138th St., New York, NY, 10031, USA

    Asif Rahaman

  4. Central High-Field NMR Research Facility, Department of Chemistry, The University of Iowa, Iowa, IA, 52242, USA

    S. V. Santhana Mariappan

  5. Free Radical and Radiation Biology Program, The University of Iowa, Iowa, IA, 52242, USA

    Garry R. Buettner

  6. School of Life Science, Engineering & Design, Saxion University of Applied Sciences, Enschede, Netherlands

    Gregor Luthe

  7. Sirindhorn College of Public Health, BanSuan, Muang, Chonburi, 2000, Thailand

    Orarat Wangpradit

  8. Luthe-Pharma, Fabrikstrasse 3, 48599, Gronau

    Gregor Luthe

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  1. Orarat Wangpradit
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  2. Asif Rahaman
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  3. S. V. Santhana Mariappan
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  4. Garry R. Buettner
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  5. Larry W. Robertson
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  6. Gregor Luthe
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Correspondence to Gregor Luthe.

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Responsible editor: Philippe Garrigues

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Wangpradit, O., Rahaman, A., Mariappan, S.V.S. et al. Breaking the dogma: PCB-derived semiquinone free radicals do not form covalent adducts with DNA, GSH, and amino acids. Environ Sci Pollut Res 23, 2138–2147 (2016). https://doi.org/10.1007/s11356-015-5007-4

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  • DOI: https://doi.org/10.1007/s11356-015-5007-4

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