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Picciano AL, Crane BR. A nitric oxide synthase-like protein from Synechococcus produces NO/NO 3- from l-arginine and NADPH in a tetrahydrobiopterin- and Ca 2+-dependent manner. J Biol Chem 2019; 294:10708-10719. [PMID: 31113865 PMCID: PMC6615690 DOI: 10.1074/jbc.ra119.008399] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/17/2019] [Indexed: 01/01/2023] Open
Abstract
Nitric oxide synthases (NOSs) are heme-based monooxygenases that convert l-Arg to l-citrulline and nitric oxide (NO), a key signaling molecule and cytotoxic agent in mammals. Bacteria also contain NOS proteins, but the role of NO production within these organisms, where understood, differs considerably from that of mammals. For example, a NOS protein in the marine cyanobacterium Synechococcus sp. PCC 7335 (syNOS) has recently been proposed to function in nitrogen assimilation from l-Arg. syNOS retains the oxygenase (NOSox) and reductase (NOSred) domains present in mammalian NOS enzymes (mNOSs), but also contains an N-terminal globin domain (NOSg) homologous to bacterial flavohemoglobin proteins. Herein, we show that syNOS functions as a dimer and produces NO from l-Arg and NADPH in a tetrahydrobiopterin (H4B)-dependent manner at levels similar to those produced by other NOSs but does not require Ca2+-calmodulin, which regulates NOSred-mediated NOSox reduction in mNOSs. Unlike other bacterial NOSs, syNOS cannot function with tetrahydrofolate and requires high Ca2+ levels (>200 μm) for its activation. NOSg converts NO to NO3- in the presence of O2 and NADPH; however, NOSg did not protect Escherichia coli strains against nitrosative stress, even in a mutant devoid of NO-protective flavohemoglobin. We also found that syNOS does not have NOS activity in E. coli (which lacks H4B) and that the recombinant protein does not confer growth advantages on l-Arg as a nitrogen source. Our findings indicate that syNOS has both NOS and NO oxygenase activities, requires H4B, and may play a role in Ca2+-mediated signaling.
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Affiliation(s)
- Angela L Picciano
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Brian R Crane
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
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Lu N, Li J, Gao Z. Key roles of Tyr 10 in Cu bound Aβ complexes and its relevance to Alzheimer's disease. Arch Biochem Biophys 2015; 584:1-9. [PMID: 26247837 DOI: 10.1016/j.abb.2015.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 07/08/2015] [Indexed: 11/26/2022]
Abstract
Recent studies show that the accumulation of redox-active Cu mediates the aggregation of amyloid β-peptide (Aβ) and conspicuous oxidative damage to the brain in Alzheimer's disease (AD). However, the key roles for Tyr 10 in Aβ-Cu(II) complex and its potential biological relevance to AD etiology under oxidative stress, were not stressed enough. Interestingly, our results indicated that Aβ40 (not Aβ16)-Cu(II) complex showed obviously enhanced peroxidase activity than free Cu(II). Although Tyr 10 was not the residue binding Cu(II), the mutation of Tyr 10 residue in Aβ40 decreased the peroxidase activity of Aβ40-Cu(II) complex, and the mutation of Tyr 10 could inhibit Aβ40 aggregation. Under oxidative and nitrative stress conditions, the Aβ-Cu(II) complex caused oxidation and nitration of the Aβ Tyr 10 residue through peroxidase-like reactions, where the formation of Cu(I) and hydroxyl radical (OH) was proposed as a chemical mechanism. We also showed that, when Aβ40 aggregates were bound to Cu(II), they retained peroxidase-like activity. Therefore, Tyr 10 residue is pivotal in Aβ-Cu(II) complex and shows important relevance to oxidative stress, implicating the novel significance of Tyr 10 residue as well as Aβ-Cu(II) complex in the pathology of AD.
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Affiliation(s)
- Naihao Lu
- Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Key Laboratory of Green Chemistry, Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, China.
| | - Jiayu Li
- Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Key Laboratory of Green Chemistry, Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, China
| | - Zhonghong Gao
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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3
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Lu N, Li J, Tian R, Peng YY. Key Roles for Tyrosine 10 in Aβ–Heme Complexes and Its Relevance to Oxidative Stress. Chem Res Toxicol 2014; 28:365-72. [DOI: 10.1021/tx5003035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Naihao Lu
- Key Laboratory of Functional Small Organic Molecule,
Ministry of
Education and College of Life Science, ‡Key Laboratory of Green Chemistry,
Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, China
| | - Jiayu Li
- Key Laboratory of Functional Small Organic Molecule,
Ministry of
Education and College of Life Science, ‡Key Laboratory of Green Chemistry,
Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, China
| | - Rong Tian
- Key Laboratory of Functional Small Organic Molecule,
Ministry of
Education and College of Life Science, ‡Key Laboratory of Green Chemistry,
Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, China
| | - Yi-Yuan Peng
- Key Laboratory of Functional Small Organic Molecule,
Ministry of
Education and College of Life Science, ‡Key Laboratory of Green Chemistry,
Jiangxi Province and College of Chemistry and Chemical Engineering, Jiangxi Normal University, 99 Ziyang Road, Nanchang, Jiangxi 330022, China
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Lu N, Chen C, He Y, Tian R, Xiao Q, Peng YY. The dual effects of nitrite on hemoglobin-dependent redox reactions. Nitric Oxide 2014; 40:1-9. [DOI: 10.1016/j.niox.2014.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 12/18/2022]
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Kim YS, Nam HJ, Chung HY, Kim ND, Ryu JH, Lee WJ, Arking R, Yoo MA. Role of xanthine dehydrogenase and aging on the innate immune response of Drosophila. J Am Aging Assoc 2013; 24:187-93. [PMID: 23604884 DOI: 10.1007/s11357-001-0020-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It has been proposed that uric acid is an important scavenger of deleterious oxygen species and peroxynitrite in biological systems. The cellular sources responsible for the generation of damage-causing reactive oxygen species (ROS) are widespread. Xanthine dehydrogenase (XDH) / oxidase (XOD) catalyzes the oxidation of xanthine to uric acid. The rosy (ry) gene encodes XDH/XOD in Drosophila melanogaster. XDH codes for uric acid which is a ROS scavenger. XOD however is an enzyme system implicated in ROS production. In this study, we investigated the roles of XDH in the fly's immune defense response to infection and in the aging process. We first compared ROS generation and nitric oxide (NO) level in the whole body and the gut of XDH mutant with those of wild type. Our results suggested that XDH has a protective effect with respect to both ROS and NO generations, particularly in the gut. We also examined the effect of a XDH deletion mutant on the relative sensitivity of the organism against bacterial infection, on the immune inducibility of antimicrobial peptides and on the effect of aging in the defensive response to infection. Our results strongly suggest that XDH plays an important role in the innate immune response and that the age-associated deterioration of the innate immune response might be, at least in part, associated with the loss of XDH activity in the aging process.
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Affiliation(s)
- Y S Kim
- Department of Molecular Biology, Pusan National University, Gumjung-ku, Pusan, 609-735 ; Institute of Genetic Engineering, Pusan National University, Gumjung-ku, Pusan, 609-735
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6
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Lu N, Zhang M, Li H, Gao Z. Completely Different Effects of Desferrioxamine on Hemin/Nitrite/H2O2-Induced Bovine Serum Albumin Nitration and Oxidation. Chem Res Toxicol 2008; 21:1229-34. [DOI: 10.1021/tx800013e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Tsikas D. Analysis of nitrite and nitrate in biological fluids by assays based on the Griess reaction: appraisal of the Griess reaction in the L-arginine/nitric oxide area of research. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 851:51-70. [PMID: 16950667 DOI: 10.1016/j.jchromb.2006.07.054] [Citation(s) in RCA: 472] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 07/17/2006] [Accepted: 07/27/2006] [Indexed: 02/07/2023]
Abstract
In the Griess reaction, first reported by Johann Peter Griess in 1879 as a method of analysis of nitrite (NO(2)(-)), nitrite reacts under acidic conditions with sulfanilic acid (HO(3)SC(6)H(4)NH(2)) to form a diazonium cation (HO(3)SC(6)H(4)-N[triple bond]N(+)) which subsequently couples to the aromatic amine 1-naphthylamine (C(10)H(7)NH(2)) to produce a red-violet coloured (lambda(max) approximately 540 nm), water-soluble azo dye (HO(3)SC(6)H(4)-NN-C(10)H(6)NH(2)). The identification of nitrite in saliva has been the first analytical application of this diazotization reaction in 1879. For a century, the Griess reaction has been exclusively used to identify analytically bacterial infection in the urogenital tract, i.e. to identify nitrite produced by bacterial reduction of nitrate (NO(3)(-)), the major nitrogen oxide anion in human urine. Since the discovery of the l-arginine/nitric oxide (l-Arg/NO) pathway in 1987, however, the Griess reaction is the most frequently used analytical approach to quantitate the major metabolites of NO, i.e. nitrite and nitrate, in a variety of biological fluids, notably blood and urine. The Griess reaction is specific for nitrite. Analysis of nitrate by this reaction requires chemical or enzymatic reduction of nitrate to nitrite prior to the diazotization reaction. The simplicity of the Griess reaction and its easy and inexpensive analytical feasibility has attracted the attention of scientists from wide a spectrum of disciplines dedicated to the complex and challenging L-Arg/NO pathway. Today, we know dozens of assays based on the Griess reaction. In principle, every laboratory in this area uses its own Griess assay. The simplest Griess assay is performed in batch commonly as originally reported by Griess. Because of the recognition of numerous interferences in the analysis of nitrite and nitrate in biological fluids and of the desire to analyze these anions simultaneously, the Griess reaction has been repeatedly modified and automated. In recent years, the Griess reaction has been coupled to HPLC, i.e. is used for post-column derivatization of chromatographically separated nitrite and nitrate. Such a HPLC-Griess system is even commercially available. The present article gives an overview of the currently available assays of nitrite and nitrate in biological fluids based on the Griess reaction. Special emphasis is given to human plasma and urine, to quantitative aspects, as well as to particular analytical and pre-analytical factors and problems that may be associated with and affect the quantitative analysis of nitrite and nitrate in these matrices by assays based on the Griess reaction. The significance of the Griess reaction in the L-Arg/NO pathway is appraised.
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Affiliation(s)
- Dimitrios Tsikas
- Institute of Clinical Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany.
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Escocard RDCM, Kanashiro MM, Petretski JH, Azevedo-Silva J, Queiroz de Carvalho EC, Dias da Silva W, Kipnis TL. Neutrophils regulate the expression of cytokines, chemokines and nitric oxide synthase/nitric oxide in mice injected with Bothrops atrox venom. Immunobiology 2006; 211:37-46. [PMID: 16446169 DOI: 10.1016/j.imbio.2005.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Accepted: 08/24/2005] [Indexed: 11/22/2022]
Abstract
Bothrops atrox crude venom injected intraperitoneal (i.p.) into BALB/c mice induced local afflux of inflammatory cells, one neutrophil-rich peak after 6h and another macrophage-rich peak after 48 h. A similar pattern of local cell afflux plus edema, Delta lesions of some skeletal muscle cells, and hemorrhage were observed in mice intramuscular (i.m.) injected with the venom. Measurement of serum cytokines in neutrophil-depleted (by anti-mouse rat monoclonal antibody (mAb) RB6-8C5) and non-depleted BALB/c mice was performed by ELISA. With the exception of IL-1beta (78 pg/ml), higher levels of IL-6 (1348 pg/ml), MIP-1beta (437 pg/ml) and MIP-2 (904 pg/ml) were observed in neutrophil-depleted mice, in comparison to the values found in non-neutrophil depleted mice: IL-1beta (437 pg/ml), IL-6 (750 pg/ml), MIP-1beta (165 pg/ml) and MIP-2 (90 pg/ml). TNF-alpha was not detected. NO was detected (18 microM) 24h after venom injection in neutrophil-depleted mice. RT-PCR using representative primers detected expression of mRNA in cells from BALB/c mice injected with B. atrox venom: (a) for IL-1beta, IL-6, inducible nitric oxide synthase (iNOS), CXCR2, MIP-2 and RANTES in cells from mice that were neutrophil-depleted or not; (b) for CCR1, CCR5 and MIP-1beta in cells from neutrophil-depleted mice; (c) for MIP-1alpha in cells from non-neutrophil-depleted mice; (d) TNF-alpha and TGF-beta were not detected in either of the mice. These results indicate that neutrophils play a role in regulating the production of some cytokines and chemokines as well as locally expressed or liberated iNOS/NO in tissues injected with B. atrox crude venom.
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Affiliation(s)
- Rita de Cássia Mothé Escocard
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense-Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
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Chen KM, El-Bayoumy K, Hosey J, Cunningham J, Aliaga C, Melikian AA. Benzene increases protein-bound 3-nitrotyrosine in bone marrow of B6C3F1 mice. Chem Biol Interact 2005; 156:81-91. [PMID: 16139254 DOI: 10.1016/j.cbi.2005.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Revised: 07/27/2005] [Accepted: 07/27/2005] [Indexed: 10/25/2022]
Abstract
Benzene, an environmental pollutant, is myelotoxic and leukemogenic in humans. The molecular mechanisms that can account for its biological effects have not been fully elucidated. We hypothesize that one of the underlying mechanism involves nitration of proteins by peroxynitrite and/or by bone marrow myeloperoxidase-dependent pathways in nitric oxide (NO) metabolism. Using 3-nitrotyrosine [Tyr(NO(2))] as a biomarker for NO-induced damage to proteins, we examined the effects of benzene on the levels of Tyr(NO(2)) in bone marrow in vivo. Groups of 8 weeks old B6C3F(1) male mice were given a single i.p. injection of benzene (50, 100, 200 or 400mg/kg bodyweight) in corn oil. The mice in control groups received either no treatment or a single injection of the vehicle. The mice were killed 1h after treatment and proteins were isolated from bone marrow, lung, liver and plasma. The proteins were enzymatically hydrolyzed; amino acids were separated and purified by high pressure liquid chromatography, derivatized, and quantified by electron capture-negative chemical ionization-gas chromatography/mass spectrometry (EC-NCI-GC/MS). In the GC/MS assay, 3-nitro-l-[(13)C(9)]tyrosine was used as an internal standard and l-[(2)H(4)]tyrosine served to monitor artifactual formation of 3-nitrotyrosine during sample preparation and analysis. We found that treatment of mice with benzene elevates nitration of tyrosine residues in bone marrow proteins. There was a dose (50-200mg benzene/kg b.w.)-dependent increase in protein-bound Tyr(NO(2)) formation (1.5- to 4.5-fold); however, the levels of Tyr(NO(2)) at 400mg benzene/kg b.w. were significantly higher than control but lower than that formed at 200mg benzene/kg b.w. The results of this study, for the first time, indicate that benzene increases protein-bound 3-Tyr(NO(2)) in bone marrow in vivo, and support our previous finding that benzene is metabolized to nitrated products in bone marrow of mice; collectively, these results may in part account for benzene-induced myelotoxicity.
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Affiliation(s)
- Kun-Ming Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, Penn State University, Hershey, PA 17033, USA
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Parnham MJ, Culić O, Eraković V, Munić V, Popović-Grle S, Barisić K, Bosnar M, Brajsa K, Cepelak I, Cuzić S, Glojnarić I, Manojlović Z, Novak-Mircetić R, Oresković K, Pavicić-Beljak V, Radosević S, Sucić M. Modulation of neutrophil and inflammation markers in chronic obstructive pulmonary disease by short-term azithromycin treatment. Eur J Pharmacol 2005; 517:132-43. [PMID: 15964564 DOI: 10.1016/j.ejphar.2005.05.023] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Revised: 05/18/2005] [Accepted: 05/24/2005] [Indexed: 10/25/2022]
Abstract
The anti-inflammatory potential of azithromycin in chronic obstructive pulmonary disease (COPD) patients was explored following a standard oral dosing regimen. Patients with moderate and severe COPD were treated with azithromycin (500 mg, n=16) or placebo (n=8) once daily for 3 days in a randomized, double blind design, to compare effects on inflammation markers with those seen in a previous study in healthy volunteers. A battery of tests was made on serum, blood neutrophils and sputum on days 1 (baseline), 3, 4, 11, 18 and 32. In comparison to placebo, azithromycin resulted in an early transient increase in serum nitrites plus nitrates (day 3), associated with a tendency towards an increase in the blood neutrophil oxidative burst to phorbol myristic acetate. Subsequently, prolonged decreases in blood leukocyte and platelet counts, serum acute phase protein (including C reactive protein) and soluble E-selectin and blood neutrophil lactoferrin concentrations and a transient decrease in serum interleukin-8 were observed. Blood neutrophil glutathione peroxidase activity showed a prolonged increase after azithromycin treatment. The biphasic facilitatory-then-inhibitory response to azithromycin seen in healthy volunteers is not so clearly detectable in COPD patients, only potential anti-inflammatory effects. Treatment for longer periods may give therapeutic anti-inflammatory benefit in these patients.
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Affiliation(s)
- Michael J Parnham
- PLIVA Research Institute Ltd, Prilaz baruna Filipovića 29, HR-10 000 Zagreb, Croatia.
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Daiber A, Bachschmid M, Kavaklí C, Frein D, Wendt M, Ullrich V, Munzel T. A new pitfall in detecting biological end products of nitric oxide-nitration, nitros(yl)ation and nitrite/nitrate artefacts during freezing. Nitric Oxide 2004; 9:44-52. [PMID: 14559431 DOI: 10.1016/j.niox.2003.08.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The present study shows that when freezing nitrite containing biological samples in the presence of sodium and phosphate, a process of tyrosine nitration and S-nitrosocysteine formation is observed. The underlying mechanism is obviously based on the already described pH decrease in sodium phosphate buffered solutions during the freezing process and probably involves nitrous acid as an intermediate. However, in pure potassium phosphate buffer freeze-artefacts were absent. The yield of 3-nitrotyrosine from albumin-bound or free tyrosine depends not only on the concentration of nitrite, tyrosine or protein, and sodium phosphate but also on the velocity of the freezing process. Nitrite and nitrate were quantified by the Griess/nitrate reductase assay. 3-nitrotyrosine formation was quantitatively measured by HPLC analysis with optical and electrochemical detection as well as qualitatively investigated by immunohistochemistry and slot blot analysis using 3-nitrotyrosine specific antibodies. The formation of S-nitrosocysteine was detected by S-nitrosothiol specific antibodies and quantified by a fluorometric assay. Irrespective of the mechanism and although the here presented results cannot be generalized, the data warrant caution for the analysis of nitration or nitros(yl)ation products following freezing of nitrite containing biological material.
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Affiliation(s)
- Andreas Daiber
- Universitätsklinikum Hamburg-Eppendorf, Medizinische Klinik III, Angiologie und Kardiologie, Martinistr 51, Hamburg 20246, Germany.
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Daiber A, Bachschmid M, Beckman JS, Munzel T, Ullrich V. The impact of metal catalysis on protein tyrosine nitration by peroxynitrite. Biochem Biophys Res Commun 2004; 317:873-81. [PMID: 15081421 DOI: 10.1016/j.bbrc.2004.03.122] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2004] [Indexed: 10/26/2022]
Abstract
In a series of heme and non-heme proteins the nitration of tyrosine residues was assessed by complete pronase digestion and subsequent HPLC-based separation of 3-nitrotyrosine. Bolus addition of peroxynitrite caused comparable nitration levels in all tested proteins. Nitration mainly depended on the total amount of tyrosine residues as well as on surface exposition. In contrast, when superoxide and nitrogen monoxide (NO) were generated at equal rates to yield low steady-state concentrations of peroxynitrite, metal catalysis seemed to play a dominant role in determining the sensitivity and selectivity of peroxynitrite-mediated tyrosine nitration in proteins. Especially, the heme-thiolate containing proteins cytochrome P450(BM-3) (wild type and F87Y variant) and prostacyclin synthase were nitrated with high efficacy. Nitration by co-generated NO/O(2)(-) was inhibited in the presence of superoxide dismutase. The NO source alone only yielded background nitration levels. Upon changing the NO/O(2)(-) ratio to an excess of NO, a decrease in nitration in agreement with trapping of peroxynitrite and derived radicals by NO was observed. These results clearly identify peroxynitrite as the nitrating species even at low steady-state concentrations and demonstrate that metal catalysis plays an important role in nitration of protein-bound tyrosine.
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Affiliation(s)
- A Daiber
- Universitätsklinikum Hamburg-Eppendorf, Medizinische Klinik III, Angiologie und Kardiologie, Martinistr. 52, 20246 Hamburg, Germany.
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