1
|
Li W, Warncke K. Native and nonnative reactions in ethanolamine ammonia-lyase are actuated by different dynamics. Biophys J 2023; 122:3976-3985. [PMID: 37641402 PMCID: PMC10560697 DOI: 10.1016/j.bpj.2023.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/13/2023] [Accepted: 08/24/2023] [Indexed: 08/31/2023] Open
Abstract
We address the contribution of select classes of solvent-coupled configurational fluctuations to the complex choreography involved in configurational and chemical steps in an enzyme by comparing native and nonnative reactions conducted at different protein internal sites. The low temperature, first-order kinetics of covalent bond rearrangement of the cryotrapped substrate radical in coenzyme B12-dependent ethanolamine ammonia-lyase (EAL) from Salmonella enterica display a kink, or increase in slope, of the Arrhenius plot with decreasing temperature. The event is associated with quenching of a select class of reaction-actuating collective fluctuations in the protein hydration layer. For comparison, a nonnative, radical reaction of the protein interior cysteine sulfhydryl group with hydrogen peroxide (H2O2) is introduced by cryotrapping EAL in an aqueous H2O2 eutectic system. The low-temperature aqueous H2O2 protein hydration and mesodomain solvent phases surrounding cryotrapped EAL are characterized by using TEMPOL spin probe electron paramagnetic resonance spectroscopy, including a freezing transition of the eutectic phase that orders the protein hydration layer. Kinetics of the cysteine-H2O2 reaction in the EAL protein interior are monitored by DEPMPO spin trapping of hydroxyl radical product. In contrast to the native reaction, the linear Arrhenius relation for the nonnative cysteine-H2O2 reaction is maintained through the solvent-protein ordering transition. The nonnative reaction is coupled to the generic local, incremental fluctuations that are intrinsic to globular proteins. The comparative approach supports the proposal that select coupled solvent-protein configurational fluctuations actuate the native reaction, and suggests that select dynamical coupling contributes to the degree of catalysis in enzymes.
Collapse
Affiliation(s)
- Wei Li
- Department of Physics, Emory University, Atlanta, Georgia
| | - Kurt Warncke
- Department of Physics, Emory University, Atlanta, Georgia.
| |
Collapse
|
2
|
Tarábek P, Lisovskaya A, Bartels DM. γ-Radiolysis of Room-Temperature Ionic Liquids: An EPR Spin-Trapping Study. J Phys Chem B 2019; 123:10837-10849. [PMID: 31742405 DOI: 10.1021/acs.jpcb.9b09155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The radiolytic stability of a series of room-temperature ionic liquids (ILs) composed of bis(trifluoromethylsulfonyl)imide anion (Tf2N-) and triethylammonium, 1-butyl-1-methylpyrrolidinium, trihexyl(tetradecyl)phosphonium, 1-hexyl-3-methylpyridinium, and 1-hexyl-3-methylimidazolium (hmim) cations was studied using spin-trap electron paramagnetic resonance (EPR) spectroscopy with a spin-trap α-(4-pyridyl N-oxide)-N-tert-butylnitrone (POBN). The trapped radical yields were measured as a function of POBN concentration and as a function of radiation dose by double integration of the broad unresolved lines. Well-resolved motionally narrowed EPR spectra for the trapped radicals were obtained by dilution of the ILs with CH2Cl2 after irradiation. The trapped radicals were identified as mainly carbon-centered alkyl and •CF3, and their ratio varies greatly across the series of ILs. Expected nitrogen-centered radicals derived from Tf2N- were not observed. The hmim liquid proved most interesting because a large part of the trapped radical yield (entirely carbon-centered) grew in over several hours after irradiation. We also discovered a complicated narrow-line stable radical signal in this neat IL with no spin trap added, which grows in over several hours after irradiation and decays over several weeks.
Collapse
Affiliation(s)
- Peter Tarábek
- Radiation Laboratory , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Alexandra Lisovskaya
- Radiation Laboratory , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - David M Bartels
- Radiation Laboratory , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| |
Collapse
|
3
|
Shen JH, Horng JJ, Wang YS, Zeng YR. The use of reactive index of hydroxyl radicals to investigate the degradation of acid orange 7 by Fenton process. CHEMOSPHERE 2017; 182:364-372. [PMID: 28505578 DOI: 10.1016/j.chemosphere.2017.05.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/15/2017] [Accepted: 05/07/2017] [Indexed: 06/07/2023]
Abstract
This study suggested the amount of hydroxyl radicals (OH) reacting with organics as a new index to evaluate the reaction efficiency (RE) of Fenton process, and used it to investigate the degradation mechanism of target pollution, Acid Orange 7 (AO7). The effects of initial concentrations of Fe(II), H2O2, and AO7 on RE were quantified by using response surface methodology (RSM). The main factors affecting RE were Fe(II), H2O2, and their interaction, and their percentage effects were 65.75, 11.99 and 22.23%, respectively. Moreover, based on the analysis result of RSM, a condition for good RE was proposed that it should ensure a higher amount of OH reacted with organics, and reduce the amount of OH scavenged by Fe(II). Liquid chromatography-mass spectrometry (LC/MS) analysis was used to identify the products of AO7 degradation in Fenton process, and there were three possible mechanisms to be observed, such as azo bond cleavage, hydroxylation, and oxidation of naphthalene ring. The trend of mechanisms might vary with the amount of OH attacks, and therefore the use of estimated RE could provide more particular information to better understand the relationship between organic degradation and OH attacks.
Collapse
Affiliation(s)
- Jyun-Hong Shen
- Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology (YunTech), Douliou, Yunlin 64002, Taiwan, ROC
| | - Jao-Jia Horng
- Department of Safety Health and Environmental Engineering, National Yunlin University of Science and Technology (YunTech), Douliou, Yunlin 64002, Taiwan, ROC.
| | - Yeoung-Sheng Wang
- Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology (YunTech), Douliou, Yunlin 64002, Taiwan, ROC
| | - Yan-Ru Zeng
- Department of Safety Health and Environmental Engineering, National Yunlin University of Science and Technology (YunTech), Douliou, Yunlin 64002, Taiwan, ROC
| |
Collapse
|
4
|
Fukuhara K, Nakashima T, Abe M, Masuda T, Hamada H, Iwamoto H, Fujitaka K, Kohno N, Hattori N. Suplatast tosilate protects the lung against hyperoxic lung injury by scavenging hydroxyl radicals. Free Radic Biol Med 2017; 106:1-9. [PMID: 28188922 DOI: 10.1016/j.freeradbiomed.2017.02.014] [Citation(s) in RCA: 15] [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: 06/28/2016] [Revised: 01/26/2017] [Accepted: 02/06/2017] [Indexed: 11/19/2022]
Abstract
Prolonged exposure to hyperoxia produces extraordinary amounts of reactive oxygen species (ROS) in the lung and causes hyperoxic lung injury. Although supraphysiological oxygen is routinely administered for the management of respiratory failure, there is no effective strategy to prevent hyperoxic lung injury. In our previous study, we showed that suplatast tosilate, an asthma drug that inhibits T helper 2 (Th2) cytokines, ameliorated bleomycin-induced lung injury and fibrosis through Th2-independent mechanisms. Because bleomycin also generates ROS, we hypothesized that suplatast tosilate might have antioxidant activity and protect the lung against hyperoxic lung injury. To test this hypothesis, mice exposed to hyperoxia were given suplatast tosilate through drinking water. Treatment with suplatast tosilate significantly prolonged mouse survival, reduced the increases in the numbers of inflammatory cells, levels of the pro-inflammatory cytokines/chemokines IL-6 and MCP-1, and protein in bronchoalveolar lavage fluid, and ameliorated lung injury in histological assessment. Suplatast tosilate treatment also significantly inhibited hyperoxia-induced elevations in the levels of 8-hydroxydeoxyguanosine, a marker of oxidative DNA damage, in bronchoalveolar lavage fluid and 8-isoprostane, a marker of lipid peroxidation, in lung tissue. This finding suggests that suplatast tosilate exerts an antioxidant activity in vivo. In addition, we investigated whether suplatast tosilate has a scavenging effect on hydroxyl radical, the most reactive and harmful ROS, using electron paramagnetic resonance spin-trapping. Suplatast tosilate was shown to scavenge hydroxyl radicals in a dose-dependent manner, and its reaction rate constant with hydroxyl radical was calculated as 2.6×1011M-1S-1, which is faster than that of several well-established antioxidants, such as ascorbate, glutathione, and cysteine. These results suggest that suplatast tosilate protects the lung against hyperoxic lung injury by decreasing the degree of oxidative stress induced by ROS, particularly by scavenging hydroxyl radicals. Suplatast tosilate might become a potential therapeutic for hyperoxic lung injury.
Collapse
Affiliation(s)
- Kazuhide Fukuhara
- Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| | - Taku Nakashima
- Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| | - Manabu Abe
- Department of Chemistry Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama,Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
| | - Takeshi Masuda
- Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| | - Hironobu Hamada
- Department of Physical Analysis and Therapeutic Sciences, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| | - Hiroshi Iwamoto
- Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| | - Kazunori Fujitaka
- Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| | - Nobuoki Kohno
- Hiroshima Cosmopolitan University, 5-13-18 Ujinanishi, Minami-ku, Hiroshima, Hiroshima 734-0014, Japan.
| | - Noboru Hattori
- Department of Molecular and Internal Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima 734-8551, Japan.
| |
Collapse
|
5
|
Shi F, Zhang P, Mao Y, Wang C, Zheng M, Zhao Z. The nitroxide Tempo inhibits hydroxyl radical production from the Fenton-like reaction of iron(II)-citrate with hydrogen peroxide. Biochem Biophys Res Commun 2016; 483:159-164. [PMID: 28042034 DOI: 10.1016/j.bbrc.2016.12.174] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 12/26/2016] [Indexed: 12/23/2022]
Abstract
In vivo physiological ligand citrate can bind iron(II) ions to form the iron(II)-citrate complex. Inhibition of hydroxyl radical (OH) production from the Fenton-like reaction of iron(II)-citrate with H2O2 is biologically important, as this reaction may account for one of the mechanisms of the labile iron pool in vivo to induce oxidative stress and pathological conditions. Nitroxides have promising potentials as therapeutic antioxidants. However, there are controversial findings indicating that they not only act as antioxidants but also as pro-oxidants when engaged in Fenton reactions. Although the underlying mechanisms are proposed to be the inhibition or enhancement of the OH production by nitroxides, the proposed elucidations are only based on assessing biological damages and not demonstrated directly by measuring the OH production in the presence of nitroxides. In this study, therefore, we employed EPR and fluorescence spectroscopies to show direct evidence that nitroxide 2,2,6,6-tetramethyl-piperidine-1-oxyl (Tempo) inhibited OH production from the Fenton-like reaction of iron(II)-citrate with H2O2 by up to 90%. We also demonstrated spectrophotometrically, for the first time, that this inhibition was due to oxidation of the iron(II)-citrate by Tempo with a stoichiometry of Tempo:Iron(III)-citrate = 1.1:1.0. A scheme was proposed to illustrate the roles of nitroxides engaged in Fenton/Fenton-like reactions.
Collapse
Affiliation(s)
- Fengqiang Shi
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Peifeng Zhang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Yujia Mao
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Can Wang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Meiqing Zheng
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Zhongwei Zhao
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China.
| |
Collapse
|
6
|
Kładna A, Berczyński P, Kruk I, Michalska T, Aboul-Enein HY. Scavenging of hydroxyl radical by catecholamines. LUMINESCENCE 2012; 27:473-7. [DOI: 10.1002/bio.1377] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 10/24/2011] [Indexed: 11/08/2022]
Affiliation(s)
- Aleksandra Kładna
- Department of Medical History and Ethics; Pomeranian Medical University of Szczecin; Poland
| | | | - Irena Kruk
- Institute of Physics; Szczecin University of Technology; Poland
| | | | - Hassan Y. Aboul-Enein
- Pharmaceutical and Medicinal Chemistry Department; Pharmaceutical and Drug Industries Research Division, National Research Centre; Dokki; Cairo; Egypt
| |
Collapse
|
7
|
Mishra B, Sharma A, Naumov S, Priyadarsini KI. Novel reactions of one-electron oxidized radicals of selenomethionine in comparison with methionine. J Phys Chem B 2009; 113:7709-15. [PMID: 19408939 DOI: 10.1021/jp900322z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pulse radiolysis studies on hydroxyl (*OH) radical reactions of selenomethionine (SeM), a selenium analogue of methionine, were carried out, and the resultant transient radical cations and their subsequent reactions have been reported. At pH<3, the >Se*-OH radical adducts produced on reaction of SeM with *OH radical were converted to selenium centered radical cations (Se*+M), which react with another molecule of SeM to form dimer radical cation M(Se therefore Se)M+. At pH 7, the >Se*-OH radical adducts were converted to a monomer radical of the type (Se therefore N)M+ that acquires intramolecular stability through interaction with the lone pair of the N atom and this radical is denoted as SeM*+. SeM*+ decayed by first order kinetics, and the reduction potential of the couple SeM*+/SeM was determined to be 1.21+/-0.05 V vs NHE at pH 7. SeM*+ oxidized ABTS2- and TMPD with rate constants of (2.5+/-0.1)x10(8) and (6.1+/-0.2)x10(8) M(-1) s(-1), respectively, and reacted with hydroxide ion with a rate constant of (3.8+/-0.9)x10(5) M(-1) s(-1). SeM*+ reacts with molecular oxygen, and the rate constant for this reaction was determined to be (4.3+/-0.2)x10(8) M(-1) s(-1); similar reaction with methionine could not be observed experimentally. Like methionine radical cations, SeM*+ undergoes decarboxylation, although with lesser yield, to produce reducing 3-methyl-selenopropyl amino radicals (referred as alpha-amino radicals). The formation of these radicals was confirmed both by the estimation of the liberated CO2 and by one-electron reduction of MV2+, thionine, and PNAP. These results have been supported by quantum chemical calculations. Implications of these results in the biological role of SeM have also been briefly discussed.
Collapse
Affiliation(s)
- B Mishra
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India
| | | | | | | |
Collapse
|
8
|
Singh U, Barik A, Priyadarsini KI. Reactions of hydroxyl radical with bergenin, a natural poly phenol studied by pulse radiolysis. Bioorg Med Chem 2009; 17:6008-14. [DOI: 10.1016/j.bmc.2009.06.055] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 06/25/2009] [Indexed: 11/26/2022]
|
9
|
Sikora A, Szajerski P, Piotrowski Ł, Zielonka J, Adamus J, Marcinek A, Gębicki J. Radical scavenging properties of nicotinamide and its metabolites. Radiat Phys Chem Oxf Engl 1993 2008. [DOI: 10.1016/j.radphyschem.2007.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
10
|
Brezová V, Dvoranová D, Staško A. Characterization of titanium dioxide photoactivity following the formation of radicals by EPR spectroscopy. RESEARCH ON CHEMICAL INTERMEDIATES 2007. [DOI: 10.1163/156856707779238630] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
11
|
Goldstein S, Czapski G, Heller A. Mode of action of poly(vinylpyridine-N-oxide) in preventing silicosis: effective scavenging of carbonate anion radical. Chem Res Toxicol 2006; 19:86-91. [PMID: 16411660 DOI: 10.1021/tx050271t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small particles of crystalline silicon dioxide (crystallites) are exceptionally toxic. Inhalation of quartz crystallites causes silicosis, a devastating lung disease afflicting miners, particularly coal and stone workers. Poly(vinylpyridine-N-oxide)s (PVPNOs) have been applied in the prevention and treatment of silicosis, but their mode of action has been obscure. Recently, the sites of inducible *NO synthase activation and of nitrotyrosine formation were associated anatomically with the pathological quartz particle-caused lesions in the lungs. It has been suggested that the *NO formed combines rapidly with O2*- to yield ONOO-, a potential mediator of lung injury following silica exposure. Here, we show that PVPNOs do not react with peroxynitrite but scavenge exceptionally rapidly CO3*- radicals, which are produced in the decomposition of ONOO- in bicarbonate solutions. The rate constant for the reaction of CO3*- with PVPNO was found to be independent of the type and size of PVPNO, i.e., k = (1.9 +/- 0.2) x 10(5) M(-1) s(-1) per monomer. In contrast, the rate constant for the reaction of CO3*- with the small molecule 4-methylpyridine N-oxide did not exceed 1 x 10(4) M(-1) s(-1). The underlying reason for the difference is that, in the dissolved polymeric PVPNOs, the electrostatic repulsion between the N-oxide zwitterions destabilizes them, increasing dramatically their pKa. The protonated N-oxides at physiological pH have abstractable hydrogen atoms and are expected to react rapidly with CO3*-, just as cyclic hydroxylamines do. It is also shown that PVPNO inhibits tyrosine nitration by peroxynitrite at pH 7.6 in the presence of excess of CO2 in a concentration-dependent manner. Hence, binding of PVPNO to the quartz particles and eliminating CO3*- could prevent the killing of macrophages, the associated release of macrophage-recruiting cytokines, and the amplification of the local concentration of *NO by the recruited macrophages. The latter causes necrosis of the macrophage-infiltrated lung tissue and, upon repair of the necrotic lesion, results in the growth of the dysfunctional fibrotic tissue, which is the hallmark of silicosis.
Collapse
Affiliation(s)
- Sara Goldstein
- Department of Physical Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
| | | | | |
Collapse
|
12
|
Bonini MG, Miyamoto S, Di Mascio P, Augusto O. Production of the Carbonate Radical Anion during Xanthine Oxidase Turnover in the Presence of Bicarbonate. J Biol Chem 2004; 279:51836-43. [PMID: 15448145 DOI: 10.1074/jbc.m406929200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Xanthine oxidase is generally recognized as a key enzyme in purine catabolism, but its structural complexity, low substrate specificity, and specialized tissue distribution suggest other functions that remain to be fully identified. The potential of xanthine oxidase to generate superoxide radical anion, hydrogen peroxide, and peroxynitrite has been extensively explored in pathophysiological contexts. Here we demonstrate that xanthine oxidase turnover at physiological pH produces a strong one-electron oxidant, the carbonate radical anion. The radical was shown to be produced from acetaldehyde oxidation by xanthine oxidase in the presence of catalase and bicarbonate on the basis of several lines of evidence such as oxidation of both dihydrorhodamine 123 and 5,5-dimethyl-1-pyrroline-N-oxide and chemiluminescence and isotope labeling/mass spectrometry studies. In the case of xanthine oxidase acting upon xanthine and hypoxanthine as substrates, carbonate radical anion production was also evidenced by the oxidation of 5,5-dimethyl-1-pyrroline-N-oxide and of dihydrorhodamine 123 in the presence of uricase. The results indicated that Fenton chemistry occurring in the bulk solution is not necessary for carbonate radical anion production. Under the conditions employed, the radical was likely to be produced at the enzyme active site by reduction of a peroxymonocarbonate intermediate whose formation and reduction is facilitated by the many xanthine oxidase redox centers. In addition to indicating that the carbonate radical anion may be an important mediator of the pathophysiological effects of xanthine oxidase, the results emphasize the potential of the bicarbonate-carbon dioxide pair as a source of biological oxidants.
Collapse
Affiliation(s)
- Marcelo G Bonini
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, São Paulo CEP 05513-970, Brazil
| | | | | | | |
Collapse
|
13
|
Goldstein S, Rosen GM, Russo A, Samuni A. Kinetics of Spin Trapping Superoxide, Hydroxyl, and Aliphatic Radicals by Cyclic Nitrones. J Phys Chem A 2004. [DOI: 10.1021/jp048441i] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sara Goldstein
- Department of Physical Chemistry, the Hebrew University of Jerusalem, Jerusalem 91904, Israel, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Medical Biotechnology Center, University of Maryland Biotechnology Institute, and Center for Low Frequency EPR Imaging for In Vivo Physiology, the University of Maryland, Baltimore, Maryland 21201, Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, Maryland 20892, and Department of Molecular Biology, the Hebrew
| | - Gerald M. Rosen
- Department of Physical Chemistry, the Hebrew University of Jerusalem, Jerusalem 91904, Israel, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Medical Biotechnology Center, University of Maryland Biotechnology Institute, and Center for Low Frequency EPR Imaging for In Vivo Physiology, the University of Maryland, Baltimore, Maryland 21201, Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, Maryland 20892, and Department of Molecular Biology, the Hebrew
| | - Angelo Russo
- Department of Physical Chemistry, the Hebrew University of Jerusalem, Jerusalem 91904, Israel, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Medical Biotechnology Center, University of Maryland Biotechnology Institute, and Center for Low Frequency EPR Imaging for In Vivo Physiology, the University of Maryland, Baltimore, Maryland 21201, Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, Maryland 20892, and Department of Molecular Biology, the Hebrew
| | - Amram Samuni
- Department of Physical Chemistry, the Hebrew University of Jerusalem, Jerusalem 91904, Israel, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Medical Biotechnology Center, University of Maryland Biotechnology Institute, and Center for Low Frequency EPR Imaging for In Vivo Physiology, the University of Maryland, Baltimore, Maryland 21201, Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, Maryland 20892, and Department of Molecular Biology, the Hebrew
| |
Collapse
|
14
|
Abe S, Kirima K, Tsuchiya K, Okamoto M, Hasegawa T, Houchi H, Yoshizumi M, Tamaki T. The Reaction Rate of Edaravone (3-Methyl-1-phenyl-2-pyrazolin-5-one (MCI-186)) with Hydroxyl Radical. Chem Pharm Bull (Tokyo) 2004; 52:186-91. [PMID: 14758002 DOI: 10.1248/cpb.52.186] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pyrazoline derivative edaravone is a potent hydroxyl radical scavenger that has been approved for attenuation of brain damage caused by ischemia-reperfusion. In the present work, we first determined the rate constant, k(r), at which edaravone scavenges radicals generated by a Fenton reaction in aqueous solution in the presence of the spin trap agent, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), which competed with edaravone. We detected the edaravone radicals in the process of hydroxyl radical scavenging and found that edaravone reacts with hydroxyl radical around the diffusion limit (k(r)=3.0 x 10(10) M(-1) s(-1)). The EPR (electron paramagnetic resonance) spectrum of the edaravone radical was observed by oxidation with a horseradish peroxidase-hydrogen peroxide system using the fast-flow method. This radical species is unstable and changed to another radical species with time. In addition, it was found that edaravone consumed molecular oxygen when it was oxidized by horseradish peroxidase (HRP)-H(2)O(2) system, and that edaravone was capable of providing two electrons to the electrophiles. The possible mechanisms for oxidation of edaravone were investigated from these findings.
Collapse
Affiliation(s)
- Shinji Abe
- Department of Pharmacology, The University of Tokushima School of Medicine, Tokushima, Japan
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Liu G, Zhao J, Hidaka H. ESR spin-trapping detection of radical intermediates in the TiO2-assisted photo-oxidation of sulforhodamine B under visible irradiation. J Photochem Photobiol A Chem 2000. [DOI: 10.1016/s1010-6030(00)00227-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
16
|
Reinke LA, Moore DR, Sang H, Janzen EG, Kotake Y. Aromatic hydroxylation in PBN spin trapping by hydroxyl radicals and cytochrome P-450. Free Radic Biol Med 2000; 28:345-50. [PMID: 10699745 DOI: 10.1016/s0891-5849(99)00248-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Phenyl N-tert-butylnitrone (PBN) is widely used as a spin trapping agent, but is not useful detecting hydroxyl radicals because the resulting spin adduct is unstable. However, hydroxyl radicals could attack the phenyl ring to form stable phenolic products with no electron paramagnetic resonance signal, and this possibility was investigated in the present studies. When PBN was added to a Fenton reaction system composed of 25 mM H(2)O(2) and 0.1 mM FeSO(4), 4-hydroxyPBN was the primary product detected, and benzoic acid was a minor product. When the Fe(2+) concentration was increased to 1.0 mM, 4-hydroxyPBN concentrations increased dramatically, and smaller amounts of benzoic acid and 2-hydroxyPBN were also formed. Although PBN is extensively metabolized after administration to animals, its metabolites have not been identified. When PBN was incubated with rat liver microsomes and a reduced nicotinamide adenine dinculeotide phosphate (NADPH)-generating system, 4-hydroxyPBN was the only metabolite detected. When PBN was given to rats, both free and conjugated 4-hydroxyPBN were readily detected in liver extracts, bile, urine, and plasma. Because 4-hydroxyPBN is the major metabolite of PBN and circulates in body fluids, it may contribute to the pharmacological properties of PBN. But 4-hydroxyPBN formation cannot be used to demonstrate hydroxyl radical formation in vivo because of its enzymatic formation.
Collapse
Affiliation(s)
- L A Reinke
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | | | | | | | | |
Collapse
|
17
|
Spin Trapping and Electron Transfer. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 1999. [DOI: 10.1016/s0065-3160(08)60193-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
|
18
|
Schwarz PF, Turro NJ, Bossmann SH, Braun AM, Wahab AMAA, Dürr H. A New Method To Determine the Generation of Hydroxyl Radicals in Illuminated TiO2 Suspensions. J Phys Chem B 1997. [DOI: 10.1021/jp971315c] [Citation(s) in RCA: 185] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | - Heinz Dürr
- Fb.:11.2 Organische Chemie, Universität des Saarlandes, 66123 Saarbrücken, Germany
| |
Collapse
|
19
|
Candeias LP, Wardman P, Mason RP. The reaction of oxygen with radicals from oxidation of tryptophan and indole-3-acetic acid. Biophys Chem 1997; 67:229-37. [PMID: 9397527 DOI: 10.1016/s0301-4622(97)00052-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The oxidation of tryptophan and indole-3-acetic acid (IAA) by the dibromine radical anion or peroxidase from horseradish in aqueous solution was investigated and compared, especially with respect to the involvement of oxygen and superoxide. Using EPR with spin-trapping, the tryptophanyl radical, generated by either method was found to react with oxygen, although this reaction is too slow to be observed by pulse radiolysis (k < 5 x 10(6) dm3 mol-1 s-1). No superoxide results from this reaction, thus excluding an electron-transfer mechanism and suggesting the formation of a tryptophan peroxyl radical, possibly in a reversible process. These observations imply that in proteins where the tryptophanyl radical exists as a stable species it must either have its reactivity modified by the protein environment or be inaccessible to oxygen. The related molecule LAA is oxidized by either peroxidase or Br2.- to a radical cation that decarboxylates to yield a skatolyl radical. The latter reacts with oxygen to give a peroxyl radical that does not release superoxide. However, O2.- is formed during the peroxidase-catalyzed oxidation of indoleacetic acid. This supports the hypothesis that the peroxidase can act in an oxidase cycle involving ferrous enzyme and compound III, with superoxide as a product.
Collapse
Affiliation(s)
- L P Candeias
- Gray Laboratory Cancer Research Trust, Mount Vernon Hospital, Northwood, Middlesex, UK
| | | | | |
Collapse
|
20
|
Madden KP, Taniguchi H. In Situ Radiolysis Time-Resolved ESR Studies of Spin Trapping by DMPO: Reevaluation of Hydroxyl Radical and Hydrated Electron Trapping Rates and Spin Adduct Yields. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp953382h] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Keith P. Madden
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556
| | - Hitoshi Taniguchi
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556
| |
Collapse
|
21
|
Shinohara N, Iwasawa M, Akiyama T. Chain Decomposition of Bis(oxalato)peroxotitanate(IV) Complex Initiated by Ti(III), Cr(II), and V(II). BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1994. [DOI: 10.1246/bcsj.67.1033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
22
|
Zubarev V, Brede O. Direct detection of the cation radical of the spin trap α-phenyl-N-tert-butylnitrone. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/p29940001821] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
23
|
Sipe HJ, Buc-Calderon P, Roberfroid M, Mason RP. Identification of the free radical formed by addition of hydroxyl radical to dehydroalanine compounds. Chem Biol Interact 1993; 86:93-102. [PMID: 8383583 DOI: 10.1016/0009-2797(93)90114-e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
N-substituted dehydroalanines, a class of compounds with both acceptor and donor substituents (ADs), react with and scavenge oxygen radicals. Interest in these compounds is based on their potential to lessen the cardiotoxicity of drugs with antineoplastic activity such as Adriamycin. The reactivity of these compounds with hydroxyl radical is evident from their inhibition of hydroxyl radical adduct formation. ESR spin trapping studies of the species formed by reaction of the AD series of compounds with the hydroxyl radical are reported here for the first time. ESR results show that hydroxyl radical attack on the capto-dative site of the AD compounds produces the predicted carbon-centered free radical.
Collapse
Affiliation(s)
- H J Sipe
- Department of Chemistry, Hampden-Sydney College, Virginia
| | | | | | | |
Collapse
|
24
|
|
25
|
|
26
|
Abstract
Spin trapping as a technique for detecting free radicals in biological systems is developing rapidly. Two conferences have focused on this method and this paper introduces the contributions resulting from the second meeting held in the Ontario Veterinary College of the University of Guelph on July 2-7, 1989. On the preceding pages can be found a poem on free radicals in biology and medicine, and the names of the sponsors and financial supporters. I am very grateful to Dr. Jim Bolton for his helpful efforts with the manuscripts.
Collapse
Affiliation(s)
- E G Janzen
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada
| |
Collapse
|
27
|
Abstract
Bioreduction in the activation of diaziquone (2,5-diaziridinyl-3,6-bis (carboethoxyamino)-1,4-benzoquinone) has been investigated by exploring its reduction by whole cells, rat liver microsomes and purified enzymes. The mechanism of bioreduction was further investigated by exploring the chemical and electrochemical reduction of diaziquone as well as its photochemistry. Reduced diaziquone (by several means) was then tested for activity against parent compound. It appears that reduced diaziquone in most cases is more active than the oxidized form. Diaziquone redox cycles, but it is easily reduced to the hydroquinone which oxidizes to the semiquinone yielding free radicals under aerobiosis. The most probable mechanism of action is that of bioreductive alkylation where the alkylating aziridines are protonated after reduction facilitating the opening of the aziridine rings and thus alkylation.
Collapse
Affiliation(s)
- P L Gutierrez
- University of Maryland Cancer Center, Baltimore, MD 21201
| |
Collapse
|
28
|
Morehouse KM, Mason RP. The transition metal-mediated formation of the hydroxyl free radical during the reduction of molecular oxygen by ferredoxin-ferredoxin:NADP+ oxidoreductase. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)57287-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
29
|
Pilas B, Felix CC, Sarna T, Kalyanaraman B. Photolysis of pheomelanin precursors: an ESR-spin trapping study. Photochem Photobiol 1986; 44:689-96. [PMID: 3031704 DOI: 10.1111/j.1751-1097.1986.tb05525.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
30
|
Fast kinetics of the reactions of hydroxyl radicals with nitrone spin traps. J Radioanal Nucl Chem 1986. [DOI: 10.1007/bf02042423] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
31
|
Mossoba MM, Gutierrez PL. Diaziquone as a potential agent for photoirradiation therapy: formation of the semiquinone and hydroxyl radicals by visible light. Biochem Biophys Res Commun 1985; 132:445-52. [PMID: 2998365 DOI: 10.1016/0006-291x(85)91042-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
When diaziquone was irradiated with 500 nm visible light, hydroxyl free radicals as well as the diaziquone semiquinone were produced. The diaziquone semiquinone is a stable free radical that exhibits a characteristic 5-line electron spin resonance (ESR) spectrum. Since hydroxyl free radicals are short lived, and not observable by conventional ESR, the nitrone spin trap 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) was used to convert hydroxyl radicals into longer lived ESR detectable spin adducts. The formation of hydroxyl radicals was further confirmed by investigating reactions in which hydroxyl radical scavangers, sodium formate and dimethylsulfoxide, compete with the spin traps DMPO or POBN (alpha-(4-Pyridyl-1-oxide)-N- tert-butylnitrone) for hydroxyl free radicals. The products of these scavenging reactions were also trapped with DMPO or POBN. If drug free radicals and hydroxyl free radicals are important in the activity of quinone-containing antitumor agents, AZQ may have a potential in photoirradiation therapy or photodynamic therapy.
Collapse
|
32
|
Faraggi M, Carmichael A, Riesz P. OH radical formation by photolysis of aqueous porphyrin solutions. A spin trapping and e.s.r. study. INTERNATIONAL JOURNAL OF RADIATION BIOLOGY AND RELATED STUDIES IN PHYSICS, CHEMISTRY, AND MEDICINE 1984; 46:703-13. [PMID: 6098562 DOI: 10.1080/09553008414551941] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Radical production during the photolysis of deaerated aqueous alkaline solutions (pH 11) of some water-soluble porphyrins was investigated. Metal-free and metallo complexes of tetrakis (4-N-methylpyridyl)porphyrin (TMPyP) and tetra (4-sulphonatophenyl)porphyrin (TPPS4) were studied. Evidence for the formation of OH radicals during photolysis at 615, 545, 435, 408 and 335 nm of Fe(III) TPPS4 is presented. Fe(III) TMPyP, Mn(III) TPPS4 and Mn(III) TMPyP also gave OH radicals but only during photolysis at 335 nm. The method of spin trapping with 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) and 4-pyridyl-1-oxide-N-tert-butylnitrone (POBN) combined with e.s.r. was used for the detection of OH, H and hydrated electrons. With the spin trap DMPO, photolysis generated DMPO-OH adducts under certain conditions but no DMPO-H adducts could be observed. With POBN, no POBN-H adducts were found. The formation of OH was confirmed by studying competition reactions for OH between the spin traps and OH scavengers (formate, isopropanol) and the concomitant formation of the CO-2 adduct and the (CH3)2COH adduct with both DMPO and POBN. The photochemical generation of OH radicals was pH dependent; at pH 7.5 no OH radicals could be detected. Photolysis (615-335 nm) of dicyanocomplexes of the Fe(III) porphyrins did not produce OH radicals. When corresponding Cu(II), Ni(II), Zn(II) and metal-free porphyrins were photolysed at 615 and 335 nm, no OH radicals could be spin trapped. These results tend to associate the well-known phenomenon of photoreduction of Fe(III) and Mn(III) porphyrins with the formation of OH radicals. This process is described mainly as the photoreduction of the metal ion by the ligand-bound hydroxyl ion via an intramolecular process.
Collapse
|
33
|
Ito O, Matsuda M. Flash Photolysis Study for Substituent and Solvent Effects on Spin-trapping Rates of Phenylthiyl Radicals with Nitrones. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1984. [DOI: 10.1246/bcsj.57.1745] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
34
|
Makino K, Moriya F, Hatano H. Application of the spin-trap HPLC-ESR method to radiation chemistry of amino acids in aqueous solutions. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0146-5724(84)90112-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
35
|
Kalyanaraman B, Felix CC, Sealy RC. PHOTOIONIZATION OF MELANIN PRECURSORS: AN ELECTRON SPIN RESONANCE INVESTIGATION USING THE SPIN TRAP 5,5-DIMETHYL-1-PYRROLINE-1-OXIDE (DMPO). Photochem Photobiol 1982. [DOI: 10.1111/j.1751-1097.1982.tb04332.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|