1
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Sentkowska A, Pyrzynska K. Catechins and Selenium Species-How They React with Each Other. Molecules 2023; 28:5897. [PMID: 37570866 PMCID: PMC10420645 DOI: 10.3390/molecules28155897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/14/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
The combination of selenium and tea infusion, both with antioxidant properties, has potentially complementary mechanisms of action. Se-enriched tea has been considered as a possible Se supplement and a functional beverage to reduce the health risk of Se deficiency. This work investigated the interactions between plant catechins present in tea infusions and selenium species based on changes in the concentration of both reagents, their stability in aqueous solutions, and the possibilities of selenonanoparticles (SeNPs) formation. Selenium species exhibited instability both alone in their standard solutions and in the presence of studied catechins; selenocystine appeared as the most unstable. The recorded UV-Vis absorption spectra indicated the formation of SeNPs in the binary mixtures of catechins and selenite. SeNPs have also formed with diameters smaller than 100 nm when selenite and selenomethionine were added to tea infusions. This is an advantage from the point of view of potential medical applications.
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Affiliation(s)
| | - Krystyna Pyrzynska
- Faculty of Chemistry, University of Warsaw, Pasteur Str. 1, 02-093 Warsaw, Poland
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2
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Hussein RA, Ahmed M, Kuldyushev N, Schönherr R, Heinemann SH. Selenomethionine incorporation in proteins of individual mammalian cells determined with a genetically encoded fluorescent sensor. Free Radic Biol Med 2022; 192:191-199. [PMID: 36152916 DOI: 10.1016/j.freeradbiomed.2022.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/14/2022] [Accepted: 09/17/2022] [Indexed: 11/26/2022]
Abstract
Selenomethionine (SeMet) randomly replaces methionine (Met) in protein translation. Because of strongly differing redox properties of SeMet and Met, SeMet mis-incorporation may have detrimental effects on protein function, possibly compromising the use of nutritional SeMet supplementation as an anti-oxidant. Studying the functional impact of SeMet in proteins on a cellular level is hampered by the lack of accurate and efficient methods for estimating the SeMet incorporation level in individual viable cells. Here we introduce and apply a method to measure the extent of SeMet incorporation in cellular proteins by utilizing a genetically encoded fluorescent methionine oxidation probe. Supplementation of SeMet in mammalian culture medium resulted in >84% incorporation of SeMet, and SeMet labeling as low as 5% was readily measured. Kinetics and extent of SeMet incorporation on the single-cell level under live-cell imaging conditions provided direct access to protein turn-over kinetics and SeMet redox properties in a cellular context. The method is furthermore suited for experiments utilizing high-throughput fluorescence microplate readers or fluorescence-activated cell sorting (FACS) analysis.
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Affiliation(s)
- Rama A Hussein
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Marwa Ahmed
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Nikita Kuldyushev
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Roland Schönherr
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany
| | - Stefan H Heinemann
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena and Jena University Hospital, Jena, Germany.
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3
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Wang Y, Xing Y, Sun J, Song C, Shen S, Huo S. Polymer Supported Methionine Selenoxide as an Excellent Immobilized Oxidant for the Formation of Disulfide Bonds in Peptides. ChemistrySelect 2022. [DOI: 10.1002/slct.202201361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yafang Wang
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics Hebei University, Baoding Hebei Province P. R. China
| | - Yueyue Xing
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics Hebei University, Baoding Hebei Province P. R. China
| | - Jingjing Sun
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics Hebei University, Baoding Hebei Province P. R. China
| | - Changing Song
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics Hebei University, Baoding Hebei Province P. R. China
| | - Shigang Shen
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics Hebei University, Baoding Hebei Province P. R. China
| | - Shuying Huo
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics Hebei University, Baoding Hebei Province P. R. China
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4
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Hou W, Xu H. Incorporating Selenium into Heterocycles and Natural Products─From Chemical Properties to Pharmacological Activities. J Med Chem 2022; 65:4436-4456. [PMID: 35244394 DOI: 10.1021/acs.jmedchem.1c01859] [Citation(s) in RCA: 65] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Selenium (Se)-containing compounds have emerged as potential therapeutic agents for the treatment of a range of diseases. Through tremendous effort, considerable knowledge has been acquired to understand the complex chemical properties and biological activities of selenium, especially after its incorporation into bioactive molecules. From this perspective, we compiled extensive literature evidence to summarize and critically discuss the relationship between the pharmacological activities and chemical properties of selenium compounds and the strategic incorporation of selenium into organic molecules, especially bioactive heterocycles and natural products. We also provide perspectives regarding the challenges in selenium-based medicinal chemistry and future research directions.
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Affiliation(s)
- Wei Hou
- College of Pharmaceutical Science and Institute of Drug Development and Chemical Biology, Zhejiang University of Technology, Hangzhou 310014, China
| | - Hongtao Xu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
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5
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Analytical Problems in Separation of Selenomethionine and Its Oxidative Product in HILIC HPLC. Molecules 2021; 26:molecules26165073. [PMID: 34443660 PMCID: PMC8398165 DOI: 10.3390/molecules26165073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 11/27/2022] Open
Abstract
Selenomethionine (SeMet) is one of the main selenium forms in foods and supplements. Determining its presence in natural food samples creates difficulties due to possible oxidation processes. The objective of this study was to evaluate the possible degradation of SeMet in water extracts of green teas, one of the most consumed beverages worldwide. Such a medium has not been investigated at this time. The HILIC-HPLC MS/MS method with different stationary phases was used to achieve the satisfactory separation of SeMet and selenomethionine oxide (SeMetO). The addition of dithiothreitol and β-mercaptoethanol, recommended to ensure that SeMet is kept in the reduced form, was also evaluated. The best separation was achieved using the zwitterionic HILIC stationary phase coupled to mass spectrometry and MeOH with water (85/15, v/v) as the eluent. Extraction was done with hot water with the addition of β-mercaptoethanol. The infusions prepared from Lung-Ching teas (from the Zhejiang Province in China) contained the highest concentration of selenium in a typical cup of tea (12.5–17.3 µg L−1). For other tested teas it decreased in the following order: Yunnan > Dilmah > Lipton. For Lung-Ching teas, the sum of concentrations of SeMet and SeMetO corresponded to about 46–63% of the total selenium in their extracts.
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6
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Abstract
Site-selective chemical bioconjugation reactions are enabling tools for the chemical biologist. Guided by a careful study of the selenomethionine (SeM) benzylation, we have refined the reaction to meet the requirements of practical protein bioconjugation. SeM is readily introduced through auxotrophic expression and exhibits unique nucleophilic properties that allow it to be selectively modified even in the presence of cysteine. The resulting benzylselenonium adduct is stable at physiological pH, is selectively labile to glutathione, and embodies a broadly tunable cleavage profile. Specifically, a 4-bromomethylphenylacetyl (BrMePAA) linker has been applied for efficient conjugation of complex organic molecules to SeM-containing proteins. This expansion of the bioconjugation toolkit has broad potential in the development of chemically enhanced proteins.
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7
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Yee EF, Oldemeyer S, Böhm E, Ganguly A, York DM, Kottke T, Crane BR. Peripheral Methionine Residues Impact Flavin Photoreduction and Protonation in an Engineered LOV Domain Light Sensor. Biochemistry 2021; 60:1148-1164. [PMID: 33787242 DOI: 10.1021/acs.biochem.1c00064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Proton-coupled electron transfer reactions play critical roles in many aspects of sensory phototransduction. In the case of flavoprotein light sensors, reductive quenching of flavin excited states initiates chemical and conformational changes that ultimately transmit light signals to downstream targets. These reactions generally require neighboring aromatic residues and proton-donating side chains for rapid and coordinated electron and proton transfer to flavin. Although photoreduction of flavoproteins can produce either the anionic (ASQ) or neutral semiquinone (NSQ), the factors that favor one over the other are not well understood. Here we employ a biologically active variant of the light-oxygen-voltage (LOV) domain protein VVD devoid of the adduct-forming Cys residue (VVD-III) to probe the mechanism of flavin photoreduction and protonation. A series of isosteric and conservative residue replacements studied by rate measurements, fluorescence quantum yields, FTIR difference spectroscopy, and molecular dynamics simulations indicate that tyrosine residues facilitate charge recombination reactions that limit sustained flavin reduction, whereas methionine residues facilitate radical propagation and quenching and also gate solvent access for flavin protonation. Replacement of a single surface Met residue with Leu favors formation of the ASQ over the NSQ and desensitizes photoreduction to oxidants. In contrast, increasing site hydrophilicity by Gln substitution promotes rapid NSQ formation and weakens the influence of the redox environment. Overall, the photoreactivity of VVD-III can be understood in terms of redundant electron donors, internal hole quenching, and coupled proton transfer reactions that all depend upon protein conformation, dynamics, and solvent penetration.
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Affiliation(s)
- Estella F Yee
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Sabine Oldemeyer
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Elena Böhm
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Abir Ganguly
- Laboratory for Biomolecular Simulation Research, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8076, United States.,Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8076, United States
| | - Darrin M York
- Laboratory for Biomolecular Simulation Research, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8076, United States.,Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8076, United States.,Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Tilman Kottke
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Brian R Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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8
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Sun J, Song C, Ma D, Shen S, Huo S. Expanding the Toolbox for Peptide Disulfide Bond Formation via l-Methionine Selenoxide Oxidation. J Org Chem 2021; 86:4035-4044. [PMID: 33620221 DOI: 10.1021/acs.joc.0c02877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, l-methionine selenoxide (MetSeO) was used as an oxidant for the construction of peptide disulfide bonds. Excellent yields for various disulfide-containing peptides were achieved via the MetSeO oxidation method in different solvents and on a resin. Most importantly, the construction of disulfide bonds can be performed in the trifluoroacetic acid cocktail used for the cleavage of peptides from the resin, which obviates the steps of peptide purification and lyophilization. This facilitates and simplifies the synthesis of disulfide-containing peptides. Kinetic and mechanistic studies of the reaction between MetSeO and dithiothreitol (DTT, a model compound of dicysteine-containing peptide) show that the reaction is first order in both [MetSeO] and [DTT], and a reaction mechanism is proposed that can help us gain insights into the reaction of the oxidative synthesis of disulfide bonds via MetSeO oxidation.
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Affiliation(s)
- Jingjing Sun
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, P. R. China
| | - Changying Song
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, P. R. China
| | - Dongying Ma
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, P. R. China
| | - Shigang Shen
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, P. R. China
| | - Shuying Huo
- College of Chemistry and Environmental Science, Key Laboratory of Analytical Science and Technology of Hebei Province, and MOE Key Laboratory of Medicinal Chemistry and Molecular Diagnostics, Hebei University, Baoding 071002, Hebei Province, P. R. China
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9
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Flouda K, Gammelgaard B, Davies MJ, Hawkins CL. Modulation of hypochlorous acid (HOCl) induced damage to vascular smooth muscle cells by thiocyanate and selenium analogues. Redox Biol 2021; 41:101873. [PMID: 33550113 PMCID: PMC7868818 DOI: 10.1016/j.redox.2021.101873] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 02/08/2023] Open
Abstract
The production of hypochlorous acid (HOCl) by myeloperoxidase (MPO) plays a key role in immune defense, but also induces host tissue damage, particularly in chronic inflammatory pathologies, including atherosclerosis. This has sparked interest in the development of therapeutic approaches that decrease HOCl formation during chronic inflammation, including the use of alternative MPO substrates. Thiocyanate (SCN−) supplementation decreases HOCl production by favouring formation of hypothiocyanous acid (HOSCN), which is more selectively toxic to bacterial cells. Selenium-containing compounds are also attractive therapeutic agents as they react rapidly with HOCl and can be catalytically recycled. In this study, we examined the ability of SCN−, selenocyanate (SeCN−) and selenomethionine (SeMet) to modulate HOCl-induced damage to human coronary artery smooth muscle cells (HCASMC), which are critical to both normal vessel function and lesion formation in atherosclerosis. Addition of SCN− prevented HOCl-induced cell death, altered the pattern and extent of intracellular thiol oxidation, and decreased perturbations to calcium homeostasis and pro-inflammatory signaling. Protection was also observed with SeCN− and SeMet, though SeMet was less effective than SeCN− and SCN−. Amelioration of damage was detected with sub-stoichiometric ratios of the added compound to HOCl. The effects of SCN− are consistent with conversion of HOCl to HOSCN. Whilst SeCN− prevented HOCl-induced damage to a similar extent to SCN−, the resulting product hyposelenocyanous acid (HOSeCN), was more toxic to HCASMC than HOSCN. These results provide support for the use of SCN− and/or selenium analogues as scavengers, to decrease HOCl-induced cellular damage and HOCl production at inflammatory sites in atherosclerosis and other pathologies. HOCl induces extensive smooth muscle cell death and irreversible thiol oxidation. Addition of SCN− decreases the extent of HOCl-induced cell damage. SeCN− has similar protective effects to SCN− towards HOCl-induced cell damage. HOSeCN is less toxic than HOCl but more damaging than HOSCN. SeMet modulates HOCl-induced damage but less effectively than SCN− or SeCN−.
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Affiliation(s)
- Konstantina Flouda
- Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen, DK-2200, Denmark
| | - Bente Gammelgaard
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, Copenhagen, DK-2100, Denmark
| | - Michael J Davies
- Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen, DK-2200, Denmark
| | - Clare L Hawkins
- Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, Copenhagen, DK-2200, Denmark.
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10
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Carroll L, Gardiner K, Ignasiak M, Holmehave J, Shimodaira S, Breitenbach T, Iwaoka M, Ogilby PR, Pattison DI, Davies MJ. Interaction kinetics of selenium-containing compounds with oxidants. Free Radic Biol Med 2020; 155:58-68. [PMID: 32439383 DOI: 10.1016/j.freeradbiomed.2020.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/07/2020] [Accepted: 05/10/2020] [Indexed: 02/03/2023]
Abstract
Selenium compounds have been identified as potential oxidant scavengers for biological applications due to the nucleophilicity of Se, and the ease of oxidation of the selenium centre. Previous studies have reported apparent second order rate constants for a number of oxidants (e.g. HOCl, ONOOH) with some selenium species, but these data are limited. Here we provide apparent second order rate constants for reaction of selenols (RSeH), selenides (RSeR') and diselenides (RSeSeR') with biologically-relevant oxidants (HOCl, H2O2, other peroxides) as well as overall consumption data for the excited state species singlet oxygen (1O2). Selenols show very high reactivity with HOCl and 1O2, with rate constants > 108 M-1 s-1, whilst selenides and diselenides typically react with rate constants one- (selenides) or two- (diselenides) orders of magnitude slower. Rate constants for reaction of diselenides with H2O2 and other hydroperoxides are much slower, with k for H2O2 being <1 M-1 s-1, and for amino acid and peptide hydroperoxides ~102 M-1 s-1. The rate constants determined for HOCl and 1O2 with these selenium species are greater than, or similar to, rate constants for amino acid side chains on proteins, including the corresponding sulfur-centered species (Cys and Met), suggesting that selenium containing compounds may be effective oxidant scavengers. Some of these reactions may be catalytic in nature due to ready recycling of the oxidized selenium species. These data may aid the development of highly efficacious, and catalytic, oxidant scavengers.
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Affiliation(s)
- Luke Carroll
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark
| | - Kelly Gardiner
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark; The Heart Research Institute, Sydney, Australia; Sydney Medical School, University of Sydney, Australia
| | - Marta Ignasiak
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark; Department of Chemistry, Adam Mickiewicz University, Poznan, Poland
| | | | - Shingo Shimodaira
- Brain Korea (BK21), Dept. of Chemistry, KAIST 373-1, Daejeon, South Korea
| | | | - Michio Iwaoka
- Department of Chemistry, Tokai University, Hiratsuka, Japan
| | - Peter R Ogilby
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - David I Pattison
- The Heart Research Institute, Sydney, Australia; Sydney Medical School, University of Sydney, Australia; Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
| | - Michael J Davies
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark; The Heart Research Institute, Sydney, Australia; Sydney Medical School, University of Sydney, Australia.
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11
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Reyes L, Bishop DP, Hawkins CL, Rayner BS. Assessing the Efficacy of Dietary Selenomethionine Supplementation in the Setting of Cardiac Ischemia/Reperfusion Injury. Antioxidants (Basel) 2019; 8:antiox8110546. [PMID: 31766199 PMCID: PMC6912310 DOI: 10.3390/antiox8110546] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 11/17/2022] Open
Abstract
Oxidative stress is a major hallmark of cardiac ischemia/reperfusion (I/R) injury. This partly arises from the presence of activated phagocytes releasing myeloperoxidase (MPO) and its production of hypochlorous acid (HOCl). The dietary supplement selenomethionine (SeMet) has been shown to bolster endogenous antioxidant processes as well as readily react with MPO-derived oxidants. The aim of this study was to assess whether supplementation with SeMet could modulate the extent of cellular damage observed in an in vitro cardiac myocyte model exposed to (patho)-physiological levels of HOCl and an in vivo rat model of cardiac I/R injury. Exposure of the H9c2 cardiac myoblast cell line to HOCl resulted in a dose-dependent increase in necrotic cell death, which could be prevented by SeMet supplementation and was attributed to SeMet preventing the HOCl-induced loss of mitochondrial inner trans-membrane potential, and the associated cytosolic calcium accumulation. This protection was credited primarily to the direct oxidant scavenging ability of SeMet, with a minor contribution arising from the ability of SeMet to bolster cardiac myoblast glutathione peroxidase (GPx) activity. In vivo, a significant increase in selenium levels in the plasma and heart tissue were seen in male Wistar rats fed a diet supplemented with 2 mg kg−1 SeMet compared to controls. However, SeMet-supplementation demonstrated only limited improvement in heart function and did not result in better heart remodelling following I/R injury. These data indicate that SeMet supplementation is of potential benefit within pathological settings where excessive HOCl is known to be generated but has limited efficacy as a therapeutic agent for the treatment of heart attack.
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Affiliation(s)
- Leila Reyes
- Heart Research Institute, Sydney 2042, Australia; (L.R.); (C.L.H.)
- Sydney Medical School, University of Sydney, Sydney 2006, Australia
| | - David P. Bishop
- School of Mathematical and Physical Sciences, Faculty of Science, University of Technology Sydney, Sydney 2007, Australia;
| | - Clare L. Hawkins
- Heart Research Institute, Sydney 2042, Australia; (L.R.); (C.L.H.)
- Sydney Medical School, University of Sydney, Sydney 2006, Australia
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Benjamin S. Rayner
- Heart Research Institute, Sydney 2042, Australia; (L.R.); (C.L.H.)
- Sydney Medical School, University of Sydney, Sydney 2006, Australia
- Correspondence: ; Tel.: +61-2808-8900
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12
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Carroll L, Pattison DI, Fu S, Schiesser CH, Davies MJ, Hawkins CL. Catalytic oxidant scavenging by selenium-containing compounds: Reduction of selenoxides and N-chloramines by thiols and redox enzymes. Redox Biol 2017; 12:872-882. [PMID: 28458184 PMCID: PMC5408155 DOI: 10.1016/j.redox.2017.04.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 04/15/2017] [Accepted: 04/17/2017] [Indexed: 01/04/2023] Open
Abstract
Myeloperoxidase produces strong oxidants during the immune response to destroy invading pathogens. However, these oxidants can also cause tissue damage, which contributes to the development of numerous inflammatory diseases. Selenium containing compounds, including selenomethionine (SeMet) and 1,4-anhydro-5-seleno-D-talitol (SeTal), react rapidly with different MPO-derived oxidants to form the respective selenoxides (SeMetO and SeTalO). This study investigates the susceptibility of these selenoxides to undergo reduction back to the parent compounds by intracellular reducing systems, including glutathione (GSH) and the glutathione reductase and thioredoxin reductase systems. GSH is shown to reduce SeMetO and SeTalO, with consequent formation of GSSG with apparent second order rate constants, k2, in the range 103–104 M−1 s−1. Glutathione reductase reduces both SeMetO and SeTalO at the expense of NADPH via formation of GSSG, whereas thioredoxin reductase acts only on SeMetO. The presence of SeMet and SeTal also increased the rate at which NADPH was consumed by the glutathione reductase system in the presence of N-chloramines. In contrast, the presence of SeMet and SeTal reduced the rate of NADPH consumption by the thioredoxin reductase system after addition of N-chloramines, consistent with the rapid formation of selenoxides, but only slow reduction by thioredoxin reductase. These results support a potential role of seleno compounds to act as catalytic scavengers of MPO-derived oxidants, particularly in the presence of glutathione reductase and NADPH, assuming that sufficient plasma levels of the parent selenoether can be achieved in vivo following supplementation. Selenoxides react with thiols including GSH by a two-step mechanism. The reaction is proposed to occur via a selenosulfide intermediate. The thioredoxin reductase system recycles selenomethionine selenoxide. The glutathione reductase system reduces both N-chloramines and selenoxides. Selenoxides can increase the reduction of N-chloramines by antioxidant systems.
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Affiliation(s)
- Luke Carroll
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen N 2200, Denmark
| | - David I Pattison
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia
| | - Shanlin Fu
- University of Technology Sydney, Centre for Forensic Science, Ultimo, NSW 2007, Australia
| | - Carl H Schiesser
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia
| | - Michael J Davies
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen N 2200, Denmark
| | - Clare L Hawkins
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen N 2200, Denmark.
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13
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Cupp-Sutton KA, Ashby MT. Biological Chemistry of Hydrogen Selenide. Antioxidants (Basel) 2016; 5:E42. [PMID: 27879667 PMCID: PMC5187540 DOI: 10.3390/antiox5040042] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/04/2016] [Accepted: 11/08/2016] [Indexed: 12/13/2022] Open
Abstract
There are no two main-group elements that exhibit more similar physical and chemical properties than sulfur and selenium. Nonetheless, Nature has deemed both essential for life and has found a way to exploit the subtle unique properties of selenium to include it in biochemistry despite its congener sulfur being 10,000 times more abundant. Selenium is more easily oxidized and it is kinetically more labile, so all selenium compounds could be considered to be "Reactive Selenium Compounds" relative to their sulfur analogues. What is furthermore remarkable is that one of the most reactive forms of selenium, hydrogen selenide (HSe- at physiologic pH), is proposed to be the starting point for the biosynthesis of selenium-containing molecules. This review contrasts the chemical properties of sulfur and selenium and critically assesses the role of hydrogen selenide in biological chemistry.
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Affiliation(s)
- Kellye A Cupp-Sutton
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA.
| | - Michael T Ashby
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA.
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Carroll L, Pattison DI, Fu S, Schiesser CH, Davies MJ, Hawkins CL. Reactivity of selenium-containing compounds with myeloperoxidase-derived chlorinating oxidants: Second-order rate constants and implications for biological damage. Free Radic Biol Med 2015; 84:279-288. [PMID: 25841785 DOI: 10.1016/j.freeradbiomed.2015.03.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/13/2015] [Accepted: 03/17/2015] [Indexed: 01/01/2023]
Abstract
Hypochlorous acid (HOCl) and N-chloramines are produced by myeloperoxidase (MPO) as part of the immune response to destroy invading pathogens. However, MPO also plays a detrimental role in inflammatory pathologies, including atherosclerosis, as inappropriate production of oxidants, including HOCl and N-chloramines, causes damage to host tissue. Low molecular mass thiol compounds, including glutathione (GSH) and methionine (Met), have demonstrated efficacy in scavenging MPO-derived oxidants, which prevents oxidative damage in vitro and ex vivo. Selenium species typically have greater reactivity toward oxidants compared to the analogous sulfur compounds, and are known to be efficient scavengers of HOCl and other hypohalous acids produced by MPO. In this study, we examined the efficacy of a number of sulfur and selenium compounds to scavenge a range of biologically relevant N-chloramines and oxidants produced by both isolated MPO and activated neutrophils and characterized the resulting selenium-derived oxidation products in each case. A dose-dependent decrease in the concentration of each N-chloramine was observed on addition of the sulfur compounds (cysteine, methionine) and selenium compounds (selenomethionine, methylselenocysteine, 1,4-anhydro-4-seleno-L-talitol, 1,5-anhydro-5-selenogulitol) studied. In general, selenomethionine was the most reactive with N-chloramines (k2 0.8-3.4×10(3)M(-1) s(-1)) with 1,5-anhydro-5-selenogulitol and 1,4-anhydro-4-seleno-L-talitol (k2 1.1-6.8×10(2)M(-1) s(-1)) showing lower reactivity. This resulted in the formation of the respective selenoxides as the primary oxidation products. The selenium compounds demonstrated greater ability to remove protein N-chloramines compared to the analogous sulfur compounds. These reactions may have implications for preventing cellular damage in vivo, particularly under chronic inflammatory conditions.
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Affiliation(s)
- Luke Carroll
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia
| | - David I Pattison
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia
| | - Shanlin Fu
- Centre for Forensic Science, University of Technology Sydney, Broadway, Sydney, NSW 2007, Australia
| | - Carl H Schiesser
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, VIC 3010, Australia
| | - Michael J Davies
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen 2200, Denmark
| | - Clare L Hawkins
- The Heart Research Institute, 7 Eliza St, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia.
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Carroll L, Davies MJ, Pattison DI. Reaction of low-molecular-mass organoselenium compounds (and their sulphur analogues) with inflammation-associated oxidants. Free Radic Res 2015; 49:750-67. [PMID: 25854915 DOI: 10.3109/10715762.2015.1018247] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Selenium is an essential trace element in mammals, with the majority specifically encoded as seleno-L-cysteine into a range of selenoproteins. Many of these proteins play a key role in modulating oxidative stress, via either direct detoxification of biological oxidants, or repair of oxidised residues. Both selenium- and sulphur-containing residues react readily with the wide range of oxidants (including hydrogen peroxide, radicals, singlet oxygen and hypochlorous, hypobromous, hypothiocyanous and peroxynitrous acids) that are produced during inflammation and have been implicated in the development of a range of inflammatory diseases. Whilst selenium has similar properties to sulphur, it typically exhibits greater reactivity with most oxidants, and there are considerable differences in the subsequent reactivity and ease of repair of the oxidised species that are formed. This review discusses the chemistry of low-molecular-mass organoselenium compounds (e.g. selenoethers, diselenides and selenols) with inflammatory oxidants, with a particular focus on the reaction kinetics and product studies, with the differences in reactivity between selenium and sulphur analogues described in the selected examples. These data provide insight into the therapeutic potential of low-molecular-mass selenium-containing compounds to modulate the activity of both radical and molecular oxidants and provide protection against inflammation-induced damage. Progress in their therapeutic development (including modulation of potential selenium toxicity by strategic design) is demonstrated by a brief summary of some recent studies where novel organoselenium compounds have been used as wound healing or radioprotection agents and in the prevention of cardiovascular disease.
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Affiliation(s)
- L Carroll
- The Heart Research Institute , Newtown, Sydney , Australia
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16
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Chwatko G, Darras VM, Bald E. A method for the determination of total and reduced methimazole in various biological samples. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014; 31:1009-16. [PMID: 24645729 DOI: 10.1080/19440049.2014.905878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A simple, rapid, reproducible and sensitive method based on HPLC with ultraviolet detection was developed for the determination of methimazole (MMI) in animal tissues and plasma samples. Under the optimum experimental conditions, the calibration curves for MMI were linear in the tested range 0.5-20 mg kg(-1) tissue sample (mg l(-1) plasma) with correlation coefficients better than 0.99. The performance of the proposed method was tested for the determination of MMI levels in brain, liver, thyroid gland and plasma of MMI-treated hens, as well as in their eggs and embryos. The proposed method reduces time and simplifies the sample preparation procedure.
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Affiliation(s)
- Grażyna Chwatko
- a Department of Environmental Chemistry, Faculty of Chemistry , University of Lodz , Lodz , Poland
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17
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Hondal RJ, Marino SM, Gladyshev VN. Selenocysteine in thiol/disulfide-like exchange reactions. Antioxid Redox Signal 2013; 18:1675-89. [PMID: 23121622 PMCID: PMC3613276 DOI: 10.1089/ars.2012.5013] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SIGNIFICANCE Among trace elements used as cofactors in enzymes, selenium is unique in that it is incorporated into proteins co-translationally in the form of an amino acid, selenocysteine (Sec). Sec differs from cysteine (Cys) by only one atom (selenium versus sulfur), yet this switch dramatically influences important aspects of enzyme reactivity. RECENT ADVANCES The main focus of this review is an updated and critical discussion on how Sec might be used to accelerate thiol/disulfide-like exchange reactions in natural selenoenzymes, compared with their Cys-containing homologs. CRITICAL ISSUES We discuss in detail three major aspects associated with thiol/disulfide exchange reactions: (i) nucleophilicity of the attacking thiolate (or selenolate); (ii) electrophilicity of the center sulfur (or selenium) atom; and (iii) stability of the leaving group (sulfur or selenium). In all these cases, we analyze the benefits that selenium might provide in these types of reactions. FUTURE DIRECTIONS It is the biological thiol oxidoreductase-like function that benefits from the use of Sec, since Sec functions to chemically accelerate the rate of these reactions. We review various hypotheses that could help explain why Sec is used in enzymes, particularly with regard to competitive chemical advantages provided by the presence of the selenium atom in enzymes. Ultimately, these chemical advantages must be connected to biological functions of Sec.
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Affiliation(s)
- Robert J Hondal
- Given Laboratory, Department of Biochemistry, University of Vermont, Burlington, VT 05405, USA.
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18
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Rahmanto AS, Davies MJ. Selenium-containing amino acids as direct and indirect antioxidants. IUBMB Life 2013; 64:863-71. [PMID: 23086812 DOI: 10.1002/iub.1084] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Selenium is a trace element essential for normal physiological processes. Organic selenium-containing amino acids, such as selenocysteine (Sec) / selenocystine and selenomethionine (SeMet, the major dietary form), can provide antioxidant benefits by acting both as direct antioxidants as well as a source of selenium for synthesis of selenium-dependent antioxidant and repair proteins (e.g., glutathione peroxidases, thioredoxin reductases, methionine sulfoxide reductases). The direct antioxidant actions of these amino acids arise from the nucleophilic properties of the ionized selenol (RSe(-), which predominates over the neutral form at physiological pH values) and the ease of oxidation of Sec and SeMet. This results in higher rate constants for reaction with multiple oxidants, than for the corresponding thiols/thioethers. Furthermore, the resulting oxidation products are more readily and rapidly reversed by both enzyme and nonenzymatic reactions. The antioxidant effects of these seleno species can therefore be catalytic. Seleno amino acids may also chelate redox-active metal ions. The presence of Sec in the catalytic site of selenium-dependent antioxidant enzymes enhances the kinetic properties and broadens the catalytic activity of antioxidant enzymes against biological oxidants when compared with sulfur-containing species. However, while normal physiological selenium levels afford protection, when compared with deficiency, excessive selenium may induce damage and adverse effects, with this being manifest, for example, as an increased incidence of type 2 diabetes. Further studies examining the availability of redox-active selenium species and their mechanisms and kinetics of action are therefore of critical importance in the potential development of seleno species as a therapeutic strategy.
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19
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Storkey C, Pattison DI, White JM, Schiesser CH, Davies MJ. Preventing protein oxidation with sugars: scavenging of hypohalous acids by 5-selenopyranose and 4-selenofuranose derivatives. Chem Res Toxicol 2012; 25:2589-99. [PMID: 23075063 DOI: 10.1021/tx3003593] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heme peroxidases including myeloperoxidase (MPO) are released at sites of inflammation by activated leukocytes. MPO generates hypohalous acids (HOX, X = Cl, Br, SCN) from H(2)O(2); these oxidants are bactericidal and are key components of the inflammatory response. However, excessive, misplaced or mistimed production can result in host tissue damage, with this implicated in multiple inflammatory diseases. We report here methods for the conversion of simple monosaccharide sugars into selenium- and sulfur-containing species that may act as potent water-soluble scavengers of HOX. Competition kinetic studies show that the seleno species react with HOCl with rate constants in the range 0.8-1.0 × 10(8) M(-1) s(-1), only marginally slower than those for the most susceptible biological targets including the endogenous antioxidant, glutathione. The rate constants for the corresponding sulfur-sugars are considerably slower (1.4-1.9 × 10(6) M(-1) s(-1)). Rate constants for reaction of the seleno-sugars with HOBr are ~8 times lower than those for HOCl (1.0-1.5 × 10(7) M(-1) s(-1)). These values show little variation with differing sugar structures. Reaction with HOSCN is slower (~10(2) M(-1) s(-1)). The seleno-sugars decreased the extent of HOCl-mediated oxidation of Met, His, Trp, Lys, and Tyr residues, and 3-chlorotyrosine formation, on both isolated bovine serum albumin and human plasma proteins, at concentrations as low as 50 μM. These studies demonstrate that novel selenium (and to a lesser extent, sulfur) derivatives of monosaccharides could be potent modulators of peroxidase-mediated damage at sites of acute and chronic inflammation, and in multiple human pathologies.
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Affiliation(s)
- Corin Storkey
- The Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia
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20
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Leis HJ, Donnarumma F, Wintersteiger R, Lazarus R, Braml B, Ortner A, Windischhofer W. Bis-pentafluorobenzyl derivatives of N-acetyl-l-methionine and N-acetyl-l-selenomethionine for the quantitative determination in human plasma by gas chromatography–negative ion chemical ionisation mass spectrometry. J Chromatogr A 2012; 1242:92-100. [DOI: 10.1016/j.chroma.2012.04.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
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21
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Misra S, Peak D, Chen N, Hamilton C, Niyogi S. Tissue-specific accumulation and speciation of selenium in rainbow trout (Oncorhynchus mykiss) exposed to elevated dietary selenomethionine. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:560-5. [PMID: 22261037 DOI: 10.1016/j.cbpc.2012.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 12/25/2011] [Accepted: 01/05/2012] [Indexed: 11/28/2022]
Abstract
The toxicity of selenium in fish is influenced by its chemical speciation and the exposure route. In the natural environment, selenium exposure to fish occurs primarily in the form of selenomethionine in diet. Thus, the main objective of this study was to examine the tissue-specific selenium burden and speciation in fish exposed to elevated dietary selenomethionine. Rainbow trout (Oncorhynchus mykiss) were treated with dietary selenomethionine (40 μg g(-1) dry mass) for 2 weeks, and at the end of the exposure different tissue samples were collected to assess the tissue-specific distribution and speciation of selenium. We used synchrotron-based X-ray absorption near edge spectroscopy (XANES) to determine the selenium speciation profile. Selenomethionine, selenocysteine and selenocystine were found to be the predominant form of selenium in all of the tissues; however their relative proportion varied across different tissues. In general, the organs primarily involved in selenium handling in fish (e.g., liver, kidney) accumulated a higher percentage of selenocystine. We also found that dietary selenomethionine exposure resulted into a marked increase in selenium burden of all major tissues in fish including the brain. Collectively, our findings provide new insights into the tissue-specific distribution and speciation of selenium in fish exposed to selenomethionine via diet.
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Affiliation(s)
- Sougat Misra
- Department of Biology, 112 Science Place, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5E2
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22
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Induction of oxidative stress by selenomethionine in isolated hepatocytes of rainbow trout (Oncorhynchus mykiss). Toxicol In Vitro 2012; 26:621-9. [PMID: 22342462 DOI: 10.1016/j.tiv.2012.02.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 01/10/2012] [Accepted: 02/04/2012] [Indexed: 11/23/2022]
Abstract
Fish are exposed to environmental selenium predominantly in the form of dietary selenomethionine (SeMet). The present study was designed to investigate the role of oxidative stress in the toxicity of SeMet using isolated hepatocytes of rainbow trout (Oncorhynchus mykiss) as the model experimental system. Cells were exposed to an increasing range of SeMet (0-1000 μM) over 24h, and the time-dependent effects on cell viability, response of enzymatic antioxidants, thiol redox, intracellular calcium balance and caspase-mediated apoptosis were evaluated. SeMet was found to be toxic only at the highest exposure dose (1000 μM), with ∼15% decrease in cell viability. Although modest increases in the activities of antioxidant enzymes were recorded following SeMet exposure, the ratio of reduced to oxidized glutathione decreased in a dose-dependent manner, suggesting a gradual progression towards an oxidative intracellular environment. The peroxidation of membrane lipids also increased with increasing SeMet exposure dose. In addition, a rapid increase in intracellular calcium level and the activation of caspase 3/7 enzymes were recorded at the highest exposure dose, indicating that SeMet at a high exposure dose causes cell death probably via apoptosis. Overall, our study demonstrated that oxidative stress plays a key role in the cytotoxicity of SeMet in fish.
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23
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Lavado R, Shi D, Schlenk D. Effects of salinity on the toxicity and biotransformation of L-selenomethionine in Japanese medaka (Oryzias latipes) embryos: mechanisms of oxidative stress. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 108:18-22. [PMID: 22265608 DOI: 10.1016/j.aquatox.2011.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 07/02/2011] [Indexed: 05/31/2023]
Abstract
Previous studies in mammals have shown that organoselenium depletes the cellular antioxidant, glutathione (GSH) due to activation of organoselenides to organoselenoxides by flavin-containing monooxygenases (FMO). Since FMO tends to be induced in euryhaline fish exposed to hypersaline conditions, the developmental toxicity of salinity and organoselenium was examined in the euryhaline fish Japanese medaka (Oryzias latipes). FMO activity, GSH, and selenium concentrations in Japanese medaka embryos were measured following a 24-h exposure to 0.05 mM L-selenomethionine (SeMet) under different saline conditions: freshwater (<0.5 dS/m), 4.2, 6.7, and 16.8 dS/m. Concentrations of GSH and the hatch-out ratio of the SeMet-treated embryos decreased in a salinity dependent manner. While SeMet treatment led to accumulation within embryos, selenium concentrations were unaltered by salinity treatment. Compared to freshwater-exposed embryos, microsomes from embryos at 6.7 and 16.8 dS/m had enhanced oxidation of SeMet to the selenoxide (10- and 14.3-fold, respectively), which correlated with GSH depletion. The results show that increased SeMet oxidation by hypersaline conditions with subsequent GSH depletion may play an important role in the developmental toxicity of selenomethionine.
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Affiliation(s)
- Ramon Lavado
- Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
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24
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Suryo Rahmanto A, Davies MJ. Catalytic activity of selenomethionine in removing amino acid, peptide, and protein hydroperoxides. Free Radic Biol Med 2011; 51:2288-99. [PMID: 22015433 DOI: 10.1016/j.freeradbiomed.2011.09.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 09/23/2011] [Accepted: 09/23/2011] [Indexed: 11/21/2022]
Abstract
Selenium is a critical trace element, with deficiency associated with numerous diseases including cardiovascular disease, diabetes, and cancer. Selenomethionine (SeMet; a selenium analogue of the amino acid methionine, Met) is a major form of organic selenium and an important dietary source of selenium for selenoprotein synthesis in vivo. As selenium compounds can be readily oxidized and reduced, and selenocysteine residues play a critical role in the catalytic activity of the key protective enzymes glutathione peroxidase and thioredoxin reductase, we investigated the ability of SeMet (and its sulfur analogue, Met) to scavenge hydroperoxides present on amino acids, peptides, and proteins, which are key intermediates in protein oxidation. We show that SeMet, but not Met, can remove these species both stoichiometrically and catalytically in the presence of glutathione (GSH) or a thioredoxin reductase (TrxR)/thioredoxin (Trx)/NADPH system. Reaction of the hydroperoxide with SeMet results in selenoxide formation as detected by HPLC. Recycling of the selenoxide back to SeMet occurs rapidly with GSH, TrxR/NADPH, or a complete TrxR/Trx/NADPH reducing system, with this resulting in an enhanced rate of peroxide removal. In the complete TrxR/Trx/NADPH system loss of peroxide is essentially stoichiometric with NADPH consumption, indicative of a highly efficient system. Similar reactions do not occur with Met under these conditions. Studies using murine macrophage-like J774A.1 cells demonstrate a greater peroxide-removing capacity in cells supplemented with SeMet, compared to nonsupplemented controls. Overall, these findings demonstrate that SeMet may play an important role in the catalytic removal of damaging peptide and protein oxidation products.
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25
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Nascimento V, Alberto EE, Tondo DW, Dambrowski D, Detty MR, Nome F, Braga AL. GPx-Like Activity of Selenides and Selenoxides: Experimental Evidence for the Involvement of Hydroxy Perhydroxy Selenane as the Active Species. J Am Chem Soc 2011; 134:138-41. [DOI: 10.1021/ja209570y] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Vanessa Nascimento
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis-SC,
Brazil
| | - Eduardo E. Alberto
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Daniel W. Tondo
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis-SC,
Brazil
| | - Daniel Dambrowski
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis-SC,
Brazil
| | - Michael R. Detty
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Faruk Nome
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis-SC,
Brazil
| | - Antonio L. Braga
- Department of Chemistry, Federal University of Santa Catarina, Florianópolis-SC,
Brazil
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26
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Martínez J, Lisa S, Sánchez R, Kowalczyk W, Zurita E, Teixidó M, Giralt E, Andreu D, Avila J, Gasset M. Selenomethionine incorporation into amyloid sequences regulates fibrillogenesis and toxicity. PLoS One 2011; 6:e27999. [PMID: 22132190 PMCID: PMC3222675 DOI: 10.1371/journal.pone.0027999] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 10/30/2011] [Indexed: 11/30/2022] Open
Abstract
Background The capacity of a polypeptide chain to engage in an amyloid formation process and cause a conformational disease is contained in its sequence. Some of the sequences undergoing fibrillation contain critical methionine (Met) residues which in vivo can be synthetically substituted by selenomethionine (SeM) and alter their properties. Methodology/Principal Findings Using peptide synthesis, biophysical techniques and cell viability determinations we have studied the effect of the substitution of methionine (Met) by selenomethionine (SeM) on the fibrillogenesis and toxic properties of Aβ40 and HuPrP(106–140). We have found that the effects display site-specificity and vary from inhibition of fibrillation and decreased toxicity ([SeM35]Aβ40, [SeM129]HuPrP(106–140) and [SeM134]HuPrP(106–140)), retarded assembly, modulation of polymer shape and retention of toxicity ([SeM112]HuPrP(106–140) to absence of effects ([SeM109]HuPrP(106–140)). Conclusions/Significance This work provides direct evidence that the substitution of Met by SeM in proamyloid sequences has a major impact on their self-assembly and toxic properties, suggesting that the SeM pool can play a major role in dictating the allowance and efficiency of a polypeptide chain to undergo toxic polymerization.
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Affiliation(s)
- Javier Martínez
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Silvia Lisa
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Rosa Sánchez
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Wioleta Kowalczyk
- Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Barcelona, Spain
| | - Esther Zurita
- Institute for Research in Biomedicine, Barcelona, Spain
| | | | - Ernest Giralt
- Institute for Research in Biomedicine, Barcelona, Spain
- Department of Organic Chemistry, University of Barcelona, Barcelona, Spain
| | - David Andreu
- Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Barcelona, Spain
| | - Jesús Avila
- Centro de Biologia Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - María Gasset
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- * E-mail:
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27
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Gammelgaard B, Jackson MI, Gabel-Jensen C. Surveying selenium speciation from soil to cell--forms and transformations. Anal Bioanal Chem 2010; 399:1743-63. [PMID: 20953781 DOI: 10.1007/s00216-010-4212-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 09/08/2010] [Indexed: 12/21/2022]
Abstract
The aim of this review is to present and evaluate the present knowledge of which selenium species are available to the general population in the form of food and common supplements and how these species are metabolized in mammals. The overview of the selenium sources takes a horizontal approach, which encompasses identification of new metabolites in yeast and food of plant and animal origin, whereas the survey of the mammalian metabolism takes a horizontal as well as a vertical approach. The vertical approach encompasses studies on dynamic conversions of selenium compounds within cells, tissues or whole organisms. New and improved sample preparation, separation and detection methods are evaluated from an analytical chemical perspective to cover the progress in horizontal speciation, whereas the analytical methods for the vertical speciation and the interpretations of the results are evaluated from a biological angle as well.
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Affiliation(s)
- Bente Gammelgaard
- Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
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28
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Hai X, Nauwelaers T, Busson R, Adams E, Hoogmartens J, Van Schepdael A. A rapid and sensitive CE method with field-enhanced sample injection and in-capillary derivatization for selenomethionine metabolism catalyzed by flavin-containing monooxygenases. Electrophoresis 2010; 31:3352-61. [DOI: 10.1002/elps.201000248] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Antioxidant and Anticancer Properties and Mechanisms of Inorganic Selenium, Oxo-Sulfur, and Oxo-Selenium Compounds. Cell Biochem Biophys 2010; 58:1-23. [PMID: 20632128 DOI: 10.1007/s12013-010-9088-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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30
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Hondal RJ, Ruggles EL. Differing views of the role of selenium in thioredoxin reductase. Amino Acids 2010; 41:73-89. [PMID: 20397034 DOI: 10.1007/s00726-010-0494-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 01/21/2010] [Indexed: 12/01/2022]
Abstract
This review covers three different chemical explanations that could account for the requirement of selenium in the form of selenocysteine in the active site of mammalian thioredoxin reductase. These views are the following: (1) the traditional view of selenocysteine as a superior nucleophile relative to cysteine, (2) the superior leaving group ability of a selenol relative to a thiol due to its significantly lower pK (a) and, (3) the superior ability of selenium to accept electrons (electrophilicity) relative to sulfur. We term these chemical explanations as the "chemico-enzymatic" function of selenium in an enzyme. We formally define the chemico-enzymatic function of selenium as its specific chemical property that allows a selenoenzyme to catalyze its individual reaction. However we, and others, question whether selenocysteine is chemically necessary to catalyze an enzymatic reaction since cysteine-homologs of selenocysteine-containing enzymes catalyze their specific enzymatic reactions with high catalytic efficiency. There must be a unique chemical reason for the presence of selenocysteine in enzymes that explains the biological pressure on the genome to maintain the complex selenocysteine-insertion machinery. We term this biological pressure the "chemico-biological" function of selenocysteine. We discuss evidence that this chemico-biological function is the ability of selenoenzymes to resist inactivation by irreversible oxidation. The way in which selenocysteine confers resistance to oxidation could be due to the superior ability of the oxidized form of selenocysteine (Sec-SeO(2)(-), seleninic acid) to be recycled back to its parent form (Sec-SeH, selenocysteine) in comparison to the same cycling of cysteine-sulfinic acid to cysteine (Cys-SO(2)(-) to Cys-SH).
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Affiliation(s)
- Robert J Hondal
- Department of Biochemistry, College of Medicine, University of Vermont, Burlington, 05405, USA.
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Bai Y, Wang T, Liu Y, Zheng W. Electrochemical oxidation of selenocystine and selenomethionine. Colloids Surf B Biointerfaces 2009; 74:150-3. [PMID: 19665878 DOI: 10.1016/j.colsurfb.2009.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 05/31/2009] [Accepted: 07/10/2009] [Indexed: 10/20/2022]
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