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Chakraborty D, Yang C, Wang L, Zhong D. Role of Substrate Binding Interactions on DNA Repair by Photolyase. J Phys Chem Lett 2023:6672-6678. [PMID: 37463310 DOI: 10.1021/acs.jpclett.3c01128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
The repair of the cyclobutane pyrimidine dimer (CPD) lesion in DNA by photolyase is determined by its initial recognition, and the catalytic efficiency depends on a series of intermolecular electron-transfer (ET) processes. Here, we investigated the repair of a CPD structural isomer, replacing the deoxyribose with a pyranose sugar on the 5' site, and found a loss in binding efficiency and repair quantum yield. Using femtosecond spectroscopy, we characterized all elementary repair steps and observed a systemic slowdown of the four intermolecular ET reactions and the second bond splitting. Our observations and molecular dynamics simulations suggest that the sugar replacement disrupts the lesion binding configuration, weakening the electronic coupling between the cofactor and lesion and altering the stability of lesion intermediates. These findings highlight how the CPD photolyases have utilized the structural features of the CPD lesion and optimized its interactions with the cofactor and key active-site residues to maximize repair yields.
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Affiliation(s)
- Debanjana Chakraborty
- Program of Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Chao Yang
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Lijuan Wang
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Dongping Zhong
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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2
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Bayer B, Saito MA, McIlvin MR, Lücker S, Moran DM, Lankiewicz TS, Dupont CL, Santoro AE. Metabolic versatility of the nitrite-oxidizing bacterium Nitrospira marina and its proteomic response to oxygen-limited conditions. THE ISME JOURNAL 2021; 15:1025-1039. [PMID: 33230266 PMCID: PMC8115632 DOI: 10.1038/s41396-020-00828-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/20/2020] [Accepted: 10/30/2020] [Indexed: 01/29/2023]
Abstract
The genus Nitrospira is the most widespread group of nitrite-oxidizing bacteria and thrives in diverse natural and engineered ecosystems. Nitrospira marina Nb-295T was isolated from the ocean over 30 years ago; however, its genome has not yet been analyzed. Here, we investigated the metabolic potential of N. marina based on its complete genome sequence and performed physiological experiments to test genome-derived hypotheses. Our data confirm that N. marina benefits from additions of undefined organic carbon substrates, has adaptations to resist oxidative, osmotic, and UV light-induced stress and low dissolved pCO2, and requires exogenous vitamin B12. In addition, N. marina is able to grow chemoorganotrophically on formate, and is thus not an obligate chemolithoautotroph. We further investigated the proteomic response of N. marina to low (∼5.6 µM) O2 concentrations. The abundance of a potentially more efficient CO2-fixing pyruvate:ferredoxin oxidoreductase (POR) complex and a high-affinity cbb3-type terminal oxidase increased under O2 limitation, suggesting a role in sustaining nitrite oxidation-driven autotrophy. This putatively more O2-sensitive POR complex might be protected from oxidative damage by Cu/Zn-binding superoxide dismutase, which also increased in abundance under low O2 conditions. Furthermore, the upregulation of proteins involved in alternative energy metabolisms, including Group 3b [NiFe] hydrogenase and formate dehydrogenase, indicate a high metabolic versatility to survive conditions unfavorable for aerobic nitrite oxidation. In summary, the genome and proteome of the first marine Nitrospira isolate identifies adaptations to life in the oxic ocean and provides insights into the metabolic diversity and niche differentiation of NOB in marine environments.
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Affiliation(s)
- Barbara Bayer
- grid.133342.40000 0004 1936 9676Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA USA
| | - Mak A. Saito
- grid.56466.370000 0004 0504 7510Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Matthew R. McIlvin
- grid.56466.370000 0004 0504 7510Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Sebastian Lücker
- grid.5590.90000000122931605Department of Microbiology, IWWR, Radboud University, Nijmegen, The Netherlands
| | - Dawn M. Moran
- grid.56466.370000 0004 0504 7510Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Thomas S. Lankiewicz
- grid.133342.40000 0004 1936 9676Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA USA
| | | | - Alyson E. Santoro
- grid.133342.40000 0004 1936 9676Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA USA
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3
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Malcomson T, Paterson MJ. Theoretical determination of two-photon absorption in biologically relevant pterin derivatives. Photochem Photobiol Sci 2020; 19:1538-1547. [PMID: 33029609 DOI: 10.1039/d0pp00255k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Given the prevalence of fluorescence spectroscopy in biological systems, and the prevalence of pterin derivatives throughout biological systems, presented here is an assessment of the two-photon absorption spectroscopy as it applies to a range of the most commonly studied pterin derivatives. QR-CAMB3LYP//ccpVTZ calculations suggest that the use of two-photon spectroscopic methods would enable a more capable differentiation between closely related derivatives in comparison to the one-photon spectra, which show minimal qualitative deviation. Study of short tail derivatives shows that, in most cases, two-photon accessible states solely involve the π* LUMO as the particle orbital, with biopterin, neopterin, and 6-(hydroxymethyl)pterin presenting exceptional potential for targetting. Investigation of derivatives in which the tail contains an aromatic ring resulted in the observation of a series of two-photon accessible states involving charge transfer from the tail to the pterin moiety, the cross sections of which are highly dependent on the adoption of a planar geometry. The observation of these states presents a novel method for tracking the substitution of biologically important molecules such as folic acid and 5-methenyltetrahydrofolylpolyglutamate.
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Affiliation(s)
- Thomas Malcomson
- Department of Chemistry, Lancaster University, Lancaster, LA1 4YB, UK.
| | - Martin J Paterson
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
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4
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Sjulstok E, Solov'yov IA. Structural Explanations of Flavin Adenine Dinucleotide Binding in Drosophila melanogaster Cryptochrome. J Phys Chem Lett 2020; 11:3866-3870. [PMID: 32330039 DOI: 10.1021/acs.jpclett.0c00625] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cryptochrome proteins are thought to be involved in light-sensitive magnetoreception in migratory birds triggered by flavin adenine dinucleotide (FAD) light absorption. A recent study, however, calls into question the ability of vertebrate cryptochrome proteins to bind FAD, rendering them unlikely to function as magnetoreceptive proteins. In this Letter, we investigate the structural changes occurring in Drosophila melanogaster cryptochrome, upon key amino acid mutations, which reduce FAD binding. Through computational analysis we have now suggested why some mutations do not preclude FAD binding in all vertebrate cryptochrome proteins.
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Affiliation(s)
- Emil Sjulstok
- Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas 75390, United States
| | - Ilia A Solov'yov
- Department of Physics, Carl von Ossietzky University, Carl von Ossietzky str. 9-11, 26111 Oldenburg, Germany
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Proteomic Response of Three Marine Ammonia-Oxidizing Archaea to Hydrogen Peroxide and Their Metabolic Interactions with a Heterotrophic Alphaproteobacterium. mSystems 2019; 4:4/4/e00181-19. [PMID: 31239395 PMCID: PMC6593220 DOI: 10.1128/msystems.00181-19] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Ammonia-oxidizing archaea (AOA) are the most abundant chemolithoautotrophic microorganisms in the oxygenated water column of the global ocean. Although H2O2 appears to be a universal by-product of aerobic metabolism, genes encoding the hydrogen peroxide (H2O2)-detoxifying enzyme catalase are largely absent in genomes of marine AOA. Here, we provide evidence that closely related marine AOA have different degrees of sensitivity to H2O2, which may contribute to niche differentiation between these organisms. Furthermore, our results suggest that marine AOA rely on H2O2 detoxification during periods of high metabolic activity and release organic compounds, thereby potentially attracting heterotrophic prokaryotes that provide this missing function. In summary, this report provides insights into the metabolic interactions between AOA and heterotrophic bacteria in marine environments and suggests that AOA play an important role in the biogeochemical carbon cycle by making organic carbon available for heterotrophic microorganisms. Ammonia-oxidizing archaea (AOA) play an important role in the nitrogen cycle and account for a considerable fraction of the prokaryotic plankton in the ocean. Most AOA lack the hydrogen peroxide (H2O2)-detoxifying enzyme catalase, and some AOA have been shown to grow poorly under conditions of exposure to H2O2. However, differences in the degrees of H2O2 sensitivity of different AOA strains, the physiological status of AOA cells exposed to H2O2, and their molecular response to H2O2 remain poorly characterized. Further, AOA might rely on heterotrophic bacteria to detoxify H2O2, and yet the extent and variety of costs and benefits involved in these interactions remain unclear. Here, we used a proteomics approach to compare the protein profiles of three Nitrosopumilus strains grown in the presence and absence of catalase and in coculture with the heterotrophic alphaproteobacterium Oceanicaulis alexandrii. We observed that most proteins detected at a higher relative abundance in H2O2-exposed Nitrosopumilus cells had no known function in oxidative stress defense. Instead, these proteins were putatively involved in the remodeling of the extracellular matrix, which we hypothesize to be a strategy limiting the influx of H2O2 into the cells. Using RNA-stable isotope probing, we confirmed that O. alexandrii cells growing in coculture with the Nitrosopumilus strains assimilated Nitrosopumilus-derived organic carbon, suggesting that AOA could recruit H2O2-detoxifying bacteria through the release of labile organic matter. Our results contribute new insights into the response of AOA to H2O2 and highlight the potential ecological importance of their interactions with heterotrophic free-living bacteria in marine environments. IMPORTANCE Ammonia-oxidizing archaea (AOA) are the most abundant chemolithoautotrophic microorganisms in the oxygenated water column of the global ocean. Although H2O2 appears to be a universal by-product of aerobic metabolism, genes encoding the hydrogen peroxide (H2O2)-detoxifying enzyme catalase are largely absent in genomes of marine AOA. Here, we provide evidence that closely related marine AOA have different degrees of sensitivity to H2O2, which may contribute to niche differentiation between these organisms. Furthermore, our results suggest that marine AOA rely on H2O2 detoxification during periods of high metabolic activity and release organic compounds, thereby potentially attracting heterotrophic prokaryotes that provide this missing function. In summary, this report provides insights into the metabolic interactions between AOA and heterotrophic bacteria in marine environments and suggests that AOA play an important role in the biogeochemical carbon cycle by making organic carbon available for heterotrophic microorganisms.
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6
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Applications of molecular modeling to flavoproteins: Insights and challenges. Methods Enzymol 2019; 620:277-314. [DOI: 10.1016/bs.mie.2019.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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7
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Estébanez S, Lorente C, Kaufman TS, Larghi EL, Thomas AH, Serrano MP. Photophysical and Photochemical Properties of 3-methylpterin as a New and More Stable Pterin-type Photosensitizer. Photochem Photobiol 2018; 94:881-889. [PMID: 29729023 DOI: 10.1111/php.12931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/12/2018] [Indexed: 11/27/2022]
Abstract
Pterin derivatives are heterocyclic compounds which are present in different biological systems. Neutral aqueous solutions of pterins present acid-base and keto-enol equilibria. These compounds, under UV-A radiation fluoresce, undergo photooxidation, generate reactive oxygen species and photoinduce the oxidation of biological substrates. As photosensitizers, they may act through different mechanisms, mainly through an electron transfer-initiated process (type-I mechanism), but they also produce singlet molecular oxygen (1 O2 ) upon irradiation (type-II mechanism). In general, upon UV-A excitation two triplet states, corresponding to the lactim and lactam tautomers, are formed, but only the last one is the responsible for the photosensitized reactions of biomolecules. We present a study of the photochemical properties of 3-methylpterin (3-Mep) which, in contrast to most pterin derivatives, exists only in the lactam form. Also an improvement in the synthesis of 3-Mep is reported. The spectroscopic properties 3-Mep in aqueous solution were similar to those of the unsubstituted pterin derivative (Ptr) in its acid form, such as absorption, fluorescent and phosphorescent emission spectra. Experiments using 2'-deoxyguanosine 5'-monophosphate (dGMP) as oxidizable target demonstrated that methylation at C-3 position of the pterin moiety does not affect significantly the efficiency of photosensitization, but results in a more photostable sensitizer.
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Affiliation(s)
- Sandra Estébanez
- Departamento de Química, Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata (UNLP), La Plata, Argentina
| | - Carolina Lorente
- Departamento de Química, Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata (UNLP), La Plata, Argentina
| | - Teodoro S Kaufman
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Enrique L Larghi
- Instituto de Química Rosario (IQUIR, CONICET-UNR) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Andrés H Thomas
- Departamento de Química, Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata (UNLP), La Plata, Argentina
| | - Mariana P Serrano
- Departamento de Química, Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata (UNLP), La Plata, Argentina
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8
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Miner BE, Kulling PM, Beer KD, Kerr B. Divergence in DNA photorepair efficiency among genotypes from contrasting UV radiation environments in nature. Mol Ecol 2015; 24:6177-87. [PMID: 26547143 DOI: 10.1111/mec.13460] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/01/2015] [Accepted: 11/03/2015] [Indexed: 02/03/2023]
Abstract
Populations of organisms routinely face abiotic selection pressures, and a central goal of evolutionary biology is to understand the mechanistic underpinnings of adaptive phenotypes. Ultraviolet radiation (UVR) is one of earth's most pervasive environmental stressors, potentially damaging DNA in any organism exposed to solar radiation. We explored mechanisms underlying differential survival following UVR exposure in genotypes of the water flea Daphnia melanica derived from natural ponds of differing UVR intensity. The UVR tolerance of a D. melanica genotype from a high-UVR habitat depended on the presence of visible and UV-A light wavelengths necessary for photoenzymatic repair of DNA damage, a repair pathway widely shared across the tree of life. We then measured the acquisition and repair of cyclobutane pyrimidine dimers, the primary form of UVR-caused DNA damage, in D. melanica DNA following experimental UVR exposure. We demonstrate that genotypes from high-UVR habitats repair DNA damage faster than genotypes from low-UVR habitats in the presence of visible and UV-A radiation necessary for photoenzymatic repair, but not in dark treatments. Because differences in repair rate only occurred in the presence of visible and UV-A radiation, we conclude that differing rates of DNA repair, and therefore differential UVR tolerance, are a consequence of variation in photoenzymatic repair efficiency. We then rule out a simple gene expression hypothesis for the molecular basis of differing repair efficiency, as expression of the CPD photolyase gene photorepair did not differ among D. melanica lineages, in both the presence and absence of UVR.
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Affiliation(s)
- Brooks E Miner
- Department of Biology, Ithaca College, 953 Danby Rd., Ithaca, NY, 14850, USA.,Department of Ecology and Evolutionary Biology, Cornell University, 215 Tower Road, E149 Corson Hall, Ithaca, NY, 14853, USA
| | - Paige M Kulling
- Department of Ecology and Evolutionary Biology, Cornell University, 215 Tower Road, E149 Corson Hall, Ithaca, NY, 14853, USA
| | - Karlyn D Beer
- Program in Molecular and Cellular Biology, University of Washington, Seattle, WA, USA.,Institute for Systems Biology, 401 Terry Ave N., Seattle, WA, 98109, USA
| | - Benjamin Kerr
- Department of Biology and BEACON Center for the Study of Evolution in Action, University of Washington, Box 351800, Seattle, WA, 98195, USA
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9
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Guo X, Liu Z, Song Q, Wang L, Zhong D. Dynamics and mechanism of UV-damaged DNA repair in indole-thymine dimer adduct: molecular origin of low repair quantum efficiency. J Phys Chem B 2015; 119:3446-55. [PMID: 25635531 DOI: 10.1021/jp512413t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many biomimetic chemical systems for repair of UV-damaged DNA showed very low repair efficiency, and the molecular origin is still unknown. Here, we report our systematic characterization of the repair dynamics of a model compound of indole-thymine dimer adduct in three solvents with different polarity. By resolving all elementary steps including three electron-transfer processes and two bond-breaking and bond-formation dynamics with femtosecond resolution, we observed the slow electron injection in 580 ps in water, 4 ns in acetonitrile, and 1.38 ns in dioxane, the fast back electron transfer without repair in 120, 150, and 180 ps, and the slow bond splitting in 550 ps, 1.9 ns, and 4.5 ns, respectively. The dimer bond cleavage is clearly accelerated by the solvent polarity. By comparing with the biological repair machine photolyase with a slow back electron transfer (2.4 ns) and a fast bond cleavage (90 ps), the low repair efficiency in the biomimetic system is mainly determined by the fast back electron transfer and slow bond breakage. We also found that the model system exists in a dynamic heterogeneous C-clamped conformation, leading to a stretched dynamic behavior. In water, we even identified another stacked form with ultrafast cyclic electron transfer, significantly reducing the repair efficiency. Thus, the comparison of the repair efficiency in different solvents is complicated and should be cautious, and only the dynamics by resolving all elementary steps can finally determine the total repair efficiency. Finally, we use the Marcus electron-transfer theory to analyze all electron-transfer reactions and rationalize all observed electron-transfer dynamics.
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Affiliation(s)
- Xunmin Guo
- Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States
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Gao S, Wang H, Zhang B, Lin Y. Surface-enhanced Raman scattering of uracil and uracil dimer on silver by density functional method. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.01.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Saleh N, Graham J, Afaneh A, Al-Soud YA, Schreckenbach G, Esmadi FT. Pteridine-based fluorescent pH sensors designed for physiological applications. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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12
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Kizilel R, Demir E, Azizoglu S, Asımgi H, Kavakli IH, Kizilel S. Investigation of real-time photorepair activity on DNA via surface plasmon resonance. PLoS One 2012; 7:e44392. [PMID: 22952969 PMCID: PMC3430658 DOI: 10.1371/journal.pone.0044392] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 08/06/2012] [Indexed: 11/18/2022] Open
Abstract
The cyclobutane pyrimidine dimer (CPD) and 6–4 lesion formations along with the specific breaks on strands are the most common type of DNA damage caused by Ultraviolet light (UV) irradiation. CPD photolyase I and II construct two subfamilies of flavoproteins, which have recognition and repair capabilities of CPD sites on both single stranded (ssDNA) and double stranded DNA (dsDNA) with the aid of blue light energy. The other types of flavoprotein family consist of cryptochromes (CRY) that act as photoreceptors in plants, or circadian rhythm regulators in animals. Recent findings showed that a specific type of Cryptochrome-Drosophila, Arabidopsis, Synechocystis, Human (CRY-DASH) has photorepair activity on ssDNA. In this work, real-time interactions between CRY-DASH and ss/dsDNA as well as the interactions between Vibrio cholerae photolyase (VcPHR) and ss/dsDNA were investigated using Surface Plasmon Resonance (SPR). The interactions were then characterized and compared in order to investigate the effect of different types of flavoprotein on UV damaged ss/dsDNA. SPR results confirm the specific binding of VcPHR and CRY-DASH with UV treated DNA. This study is the first instance to quantify the interactions of UV treated and untreated DNA with flavoproteins.
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Affiliation(s)
- Rıza Kizilel
- Chemical and Biological Engineering, Koc University, Sariyer, Istanbul, Turkey
- * E-mail: (SK); (IHK); (RK)
| | - Enis Demir
- Chemical and Biological Engineering, Koc University, Sariyer, Istanbul, Turkey
| | - Selimcan Azizoglu
- Chemical and Biological Engineering, Koc University, Sariyer, Istanbul, Turkey
| | - Hande Asımgi
- Chemical and Biological Engineering, Koc University, Sariyer, Istanbul, Turkey
- Material Science and Engineering, Koc University, Sariyer, Istanbul, Turkey
| | - Ibrahim Halil Kavakli
- Chemical and Biological Engineering, Koc University, Sariyer, Istanbul, Turkey
- Material Science and Engineering, Koc University, Sariyer, Istanbul, Turkey
- Molecular Biology and Genetics, Koc University, Sariyer, Istanbul, Turkey
- * E-mail: (SK); (IHK); (RK)
| | - Seda Kizilel
- Chemical and Biological Engineering, Koc University, Sariyer, Istanbul, Turkey
- Material Science and Engineering, Koc University, Sariyer, Istanbul, Turkey
- * E-mail: (SK); (IHK); (RK)
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Kiontke S, Geisselbrecht Y, Pokorny R, Carell T, Batschauer A, Essen LO. Crystal structures of an archaeal class II DNA photolyase and its complex with UV-damaged duplex DNA. EMBO J 2011; 30:4437-49. [PMID: 21892138 DOI: 10.1038/emboj.2011.313] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 08/02/2011] [Indexed: 01/29/2023] Open
Abstract
Class II photolyases ubiquitously occur in plants, animals, prokaryotes and some viruses. Like the distantly related microbial class I photolyases, these enzymes repair UV-induced cyclobutane pyrimidine dimer (CPD) lesions within duplex DNA using blue/near-UV light. Methanosarcina mazei Mm0852 is a class II photolyase of the archaeal order of Methanosarcinales, and is closely related to plant and metazoan counterparts. Mm0852 catalyses light-driven DNA repair and photoreduction, but in contrast to class I enzymes lacks a high degree of binding discrimination between UV-damaged and intact duplex DNA. We solved crystal structures of Mm0852, the first one for a class II photolyase, alone and in complex with CPD lesion-containing duplex DNA. The lesion-binding mode differs from other photolyases by a larger DNA-binding site, and an unrepaired CPD lesion is found flipped into the active site and recognized by a cluster of five water molecules next to the bound 3'-thymine base. Different from other members of the photolyase-cryptochrome family, class II photolyases appear to utilize an unusual, conserved tryptophane dyad as electron transfer pathway to the catalytic FAD cofactor.
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Affiliation(s)
- Stephan Kiontke
- Faculty of Chemistry, Department of Biochemistry, Philipps University, Marburg, Germany
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14
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Cho DW, Lee CW, Park JG, Oh SW, Sung NK, Park HJ, Kim KM, Mariano PS, Yoon UC. Exploration of photochemical reactions of N-trimethylsilylmethyl-substituted uracil, pyridone, and pyrrolidone derivatives. Photochem Photobiol Sci 2011; 10:1169-80. [PMID: 21472163 DOI: 10.1039/c0pp00372g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photochemical reactions of N-trimethylsilylmethyl-substituted uracil, pyridone and pyrrolidone derivatives were carried out to determine if silicone containing substituents have an impact on excited state reaction profiles. The results show that ultraviolet irradiation of N-trimethylsilylmethyl substituted uracils in the presence of substituted alkenes leads to efficient formation of both dimeric and cross [2+2]-cycloaddition products. Qualitatively similar observations were made in a study of the photochemistry of N-trimethylsilylmethyl-2-pyridone. The combined results demonstrate that [2+2]-photocycloaddition is a more efficient excited state reaction pathway for the uracil and pyridone substrates as compared to other processes, such as ylide-forming trimethylsilyl group C-to-O migration. Finally, photoreactions of N-trimethylsilylmethyl-2-pyrrolidone in solutions containing dipolarophiles, such as methyl acrylate, lead to the formation of the desilylation product, N-methyl-2-pyrrolidone by way of a simple, non-ylide generating, protodesilylation process. In addition, observations were made which show that orbital symmetry allowed photocycloreversion reactions of dimeric uracil derivatives, involving cyclobutane ring splitting, to take place. These processes, which lead to the formation of monomeric uracils, appear to be stimulated by the presence of electron donor groups on the cyclobutane ring, a likely result of a new SET promoted cyclobutane ring cleavage pathway. In the cases of N-trimethylsilylmethyl-substituted cyclobutane derivatives that possess phthalimide groups, highly efficient excited state cleavage of the cyclobutane moiety occurs to produce uracil derivatives and corresponding vinyl phthalimide.
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Affiliation(s)
- Dae Won Cho
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, 609-735, Korea
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15
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Liese J, Hampp N. Thermal [2 + 2] Cycloreversion of a Cyclobutane Moiety via a Biradical Reaction. J Phys Chem A 2011; 115:2927-32. [DOI: 10.1021/jp111577j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Liese
- Department of Chemistry, Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. Bldg. H, D-35032 Marburg, Germany
| | - N. Hampp
- Department of Chemistry, Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. Bldg. H, D-35032 Marburg, Germany
- Material Sciences Center, Philipps-University Marburg, D-35032 Marburg, Germany
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Kritsky MS, Telegina TA, Vechtomova YL, Kolesnikov MP, Lyudnikova TA, Golub OA. Excited flavin and pterin coenzyme molecules in evolution. BIOCHEMISTRY (MOSCOW) 2010; 75:1200-16. [DOI: 10.1134/s0006297910100020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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17
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Thorne RE, Chinnapen DJF, Sekhon GS, Sen D. A deoxyribozyme, Sero1C, uses light and serotonin to repair diverse pyrimidine dimers in DNA. J Mol Biol 2009; 388:21-9. [PMID: 19281822 DOI: 10.1016/j.jmb.2009.02.064] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 02/10/2009] [Accepted: 02/28/2009] [Indexed: 11/19/2022]
Abstract
An in vitro selection search for DNAs capable of catalyzing photochemistry yielded two distinctive deoxyribozymes (DNAzymes) with photolyase activity: UV1C, which repaired thymine dimers within DNA using a UV light of >300 nm wavelength and no extraneous cofactor, and Sero1C, which required the tryptophan metabolite serotonin as cofactor in addition to the UV light. Catalysis by Sero1C conformed to Michaelis-Menten kinetics, and analysis of the action spectrum of Sero1C confirmed that serotonin did indeed serve as a catalytic cofactor rather than as a structural cofactor. Sero1C and UV1C showed strikingly distinct wavelength optima for their respective photoreactivation catalyses. Although the rate enhancements characteristic of the two DNAzymes were similar, the cofactor-requiring Sero1C repaired a substantially broader range of substrates compared to UV1C, including thymine, uracil, and a range of chimeric deoxypyrimidine and ribopyrimidine dimers. Similarities and differences in the properties of these two photolyase DNAzymes suggest, first, that the harnessing of less damaging UV light for the repair of photolesions may have been a primordial catalytic activity of nucleic acids, and, second, the broader substrate range of Sero1C may highlight an evolutionary advantage to coopting amino-acid-like cofactors by functionality-poor nucleic acid enzymes.
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Affiliation(s)
- Rebecca E Thorne
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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Lyudnikova TA, Dashina OA, Telegina TA, Kritsky MS. Investigation of the photochemical properties of biopterin and its reduced forms. APPL BIOCHEM MICRO+ 2009. [DOI: 10.1134/s0003683809010189] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Dong Q, Todd Monroe W, Tiersch TR, Svoboda KR. UVA-induced photo recovery during early zebrafish embryogenesis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2008; 93:162-71. [PMID: 18845445 DOI: 10.1016/j.jphotobiol.2008.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2008] [Revised: 07/14/2008] [Accepted: 07/28/2008] [Indexed: 01/29/2023]
Abstract
DNA photorepair has been widely studied in simple aquatic organisms that live in the marine environment, but is less understood in more complex species that live in freshwater. In the present study, we evaluated UVA-induced DNA photo recovery in embryonic stages of zebrafish, Danio rerio, a freshwater model species. Evaluation of UVB exposure and UVA photo recovery of zebrafish embryos revealed different UVB tolerances and capacities for UVA photo recovery at different stages of development. Effective UVA photo recovery was observed at 3h post-fertilization (hpf), 6-7 hpf, and 12 hpf, but not in the early cleavage stage (2-32 cells). UVA photo recovery was most effective during the gastrula stage (6-7 hpf) of development, and less effective at earlier stages (e.g., 3 hpf) or later stages (e.g., 12 hpf). Embryos at the cleavage stage of development were found to be tolerant to extreme levels of UVB exposure, and possible mechanisms were discussed. For embryos at 6-7 hpf, examination of time window (or delay of UVA exposure) that would still permit recovery from UVB exposure suggested a short time period of 2h. The transgenic fli-1 zebrafish with fluorescent vascular structure was used to show that embryos with normal morphological appearance could exhibit a disrupted vascular patterning, suggesting that this endpoint could provide a sensitive tool for detection of UV damage.
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Affiliation(s)
- Qiaoxiang Dong
- Department of Biological and Agricultural Engineering, Louisiana State University and LSU Agricultural Center, Baton Rouge, LA 70803, USA
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Beukers R, Eker APM, Lohman PHM. 50 years thymine dimer. DNA Repair (Amst) 2008; 7:530-43. [PMID: 18191622 DOI: 10.1016/j.dnarep.2007.11.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Accepted: 11/14/2007] [Indexed: 10/22/2022]
Abstract
Fifty years ago thymine dimer was discovered in the Biochemical and Biophysical Laboratory of Delft Technological University, The Netherlands, by one of the authors of this review (Beukers) as the first environmentally induced DNA lesion. It is one of the photoproducts formed between adjacent pyrimidine bases in DNA by UV irradiation, currently known as cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts. Major lesions found in DNA after in vitro or in vivo UV irradiation are the cis-syn cyclobutane thymine dimer and the thymine-cytosine (6-4) photoproduct. Even after 50 years the study of photo-induced DNA lesions is still going on as is illustrated by the hundreds of papers published every year and the millions hits when browsing the internet for dimer-related information. Living organisms possess efficient and different mechanisms to repair detrimental lesions in their DNA. A unique mechanism to repair CPDs is reversion by either direct interaction with light of short wavelength or by enzymatic photoreactivation. Photophysical mechanisms that induce and reverse molecular bonds in biological macromolecules have been a main focus of research of the group in Delft in the middle of the last century. This review describes the break-through results of these studies which were the result of intense interactions between scientists in the fields of physics, organic chemistry and biochemistry. Philosophically, the "view" of the group in Delft was very appealing: since in nature photolesions are induced in DNA by the sun, how is it possible that repair of these lesions could be accomplished by the same energy source. Evolutionary, it is hardly possible to think of a more efficient repair mechanism.
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Affiliation(s)
- Rob Beukers
- Department of Cell Biology and Genetics, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands.
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Weber S, Bittl R. Studies of Organic Protein Cofactors Using Electron Paramagnetic Resonance. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.2270] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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22
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Chen X, Xu X, Cao Z. Theoretical Study on the Singlet Excited State of Pterin and Its Deactivation Pathway. J Phys Chem A 2007; 111:9255-62. [PMID: 17629256 DOI: 10.1021/jp0727502] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The excited-state properties and related photophysical processes of the acidic and basic forms of pterin have been investigated by the density functional theory and ab initio methodologies. The solvent effects on the low-lying states have been estimated by the polarized continuum model and combined QM/MM calculations. Calculations reveal that the observed two strong absorptions arise from the strong pi --> pi* transitions to 1(pipi*L(a)) and 1(pipi*L(b)) in the acidic and basic forms of pterin. The first 1(pipi*L(a)) excited state is exclusively responsible for the experimental emission band. The vertical 1(n(N)pi*) state with a small oscillator strength, slightly higher in energy than the 1(pipi*L(a)) state, is less accessible by the direct electronic transition. The 1(n(N)pi*) state may be involved in the photophysical process of the excited pterin via the 1(pipi*L(a)/n(N)pi*) conical intersection. The radiationless decay of the excited PT to the ground state experiences a barrier of 13.8 kcal/mol for the acidic form to reach the (S(1)/S(0)) conical intersection. Such internal conversion can be enhanced with the increase in excitation energy, which will reduce the fluorescence intensity as observed experimentally.
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Affiliation(s)
- Xing Chen
- Department of Chemistry and State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China
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Cabrerizo FM, Lorente C, Vignonl M, Cabrerizo R, Thomas AH, Capparelli AL. Photochemical Behavior of 6-Methylpterin in Aqueous Solutions: Generation of Reactive Oxygen Species¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb01445.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Choe YK, Nagase S, Nishimoto K. Theoretical study of the electronic spectra of oxidized and reduced states of lumiflavin and its derivative. J Comput Chem 2007; 28:727-39. [PMID: 17226839 DOI: 10.1002/jcc.20533] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Time-dependent density functional theory has been applied to investigate the electronic absorption spectrum of oxidized and reduced lumiflavin and its derivative, 8-NH(2)-lumiflavin. The calculations allow the authors to explain the origin of the difference in spectral features between oxidized and reduced states of lumiflavin. For the reduced lumiflavin, a reasonable assignment of the experimental spectrum has been made for the first time. Furthermore, the results obtained reveal that the NH(2) group plays a critical role in shaping the spectral features of 8-NH(2)-lumiflavin, and offer a reasonable explanation for the spectral changes upon substituting the NH(2) group for the CH(3) group of lumiflavin.
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Affiliation(s)
- Yoong-Kee Choe
- Research Institute for Computational Sciences (RICS), National Institute of Advanced Industrial Science and Technology (AIST), Centeral-2, Umezono 1-1-1, Tsukuba 305-8578, Japan.
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25
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Thomas A, Cabrerizo R, Vignoni M, Erra-Balsells R, Cabrerizo F, Capparelli A. Photoinduced Formation of Reactive Oxygen Species from the Acid Form of 6-(Hydroxymethyl)pterin in Aqueous Solution. Helv Chim Acta 2006. [DOI: 10.1002/hlca.200690107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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Tang WJ, Song QH, Wang HB, Yu JY, Guo QX. Efficient photosensitized splitting of the thymine dimer/oxetane unit on its modifying beta-cyclodextrin by a binding electron donor. Org Biomol Chem 2006; 4:2575-80. [PMID: 16791321 DOI: 10.1039/b604529d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two modified beta-cyclodextrins (beta-CDs) with a thymine dimer and a thymine oxetane adduct respectively, TD-CD and Ox-CD, have been prepared, and utilized to bind an electron-rich chromophore, indole or N,N-dimethylaniline (DMA), to form a supramolecular complex. We have examined the photosensitized splitting of the dimer/oxetane unit in TD-CD/Ox-CD by indole or DMA via an electron-transfer pathway, and observed high splitting efficiencies of the dimer/oxetane unit. On the basis of measurements of fluorescence spectra and splitting quantum yields, it is suggested that the splitting reaction occurs in a supramolecular complex by an inclusion interaction between the modified beta-CDs and DMA or indole. The back electron transfer, which leads low splitting efficiencies for the covalently-linked chromophore-dimer/oxetane compounds, is suppressed in the non-covalently-bound complex, and the mechanism has been discussed.
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Affiliation(s)
- Wen-Jian Tang
- Department of Chemistry, University of Science and Technology of China, and State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Hefei, Anhui.
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27
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Au N, Kuester-Schoeck E, Mandava V, Bothwell LE, Canny SP, Chachu K, Colavito SA, Fuller SN, Groban ES, Hensley LA, O'Brien TC, Shah A, Tierney JT, Tomm LL, O'Gara TM, Goranov AI, Grossman AD, Lovett CM. Genetic composition of the Bacillus subtilis SOS system. J Bacteriol 2005; 187:7655-66. [PMID: 16267290 PMCID: PMC1280312 DOI: 10.1128/jb.187.22.7655-7666.2005] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The SOS response in bacteria includes a global transcriptional response to DNA damage. DNA damage is sensed by the highly conserved recombination protein RecA, which facilitates inactivation of the transcriptional repressor LexA. Inactivation of LexA causes induction (derepression) of genes of the LexA regulon, many of which are involved in DNA repair and survival after DNA damage. To identify potential RecA-LexA-regulated genes in Bacillus subtilis, we searched the genome for putative LexA binding sites within 300 bp upstream of the start codons of all annotated open reading frames. We found 62 genes that could be regulated by putative LexA binding sites. Using mobility shift assays, we found that LexA binds specifically to DNA in the regulatory regions of 54 of these genes, which are organized in 34 putative operons. Using DNA microarray analyses, we found that 33 of the genes with LexA binding sites exhibit RecA-dependent induction by both mitomycin C and UV radiation. Among these 33 SOS genes, there are 22 distinct LexA binding sites preceding 18 putative operons. Alignment of the distinct LexA binding sites reveals an expanded consensus sequence for the B. subtilis operator: 5'-CGAACATATGTTCG-3'. Although the number of genes controlled by RecA and LexA in B. subtilis is similar to that of Escherichia coli, only eight B. subtilis RecA-dependent SOS genes have homologous counterparts in E. coli.
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Affiliation(s)
- Nora Au
- Department of Chemistry, Williams College, Williamstown, MA 01267, USA
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Weber S. Light-driven enzymatic catalysis of DNA repair: a review of recent biophysical studies on photolyase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1707:1-23. [PMID: 15721603 DOI: 10.1016/j.bbabio.2004.02.010] [Citation(s) in RCA: 254] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2003] [Accepted: 02/02/2004] [Indexed: 11/19/2022]
Abstract
More than 50 years ago, initial experiments on enzymatic photorepair of ultraviolet (UV)-damaged DNA were reported [Proc. Natl. Acad. Sci. U. S. A. 35 (1949) 73]. Soon after this discovery, it was recognized that one enzyme, photolyase, is able to repair UV-induced DNA lesions by effectively reversing their formation using blue light. The enzymatic process named DNA photoreactivation depends on a non-covalently bound cofactor, flavin adenine dinucleotide (FAD). Flavins are ubiquitous redox-active catalysts in one- and two-electron transfer reactions of numerous biological processes. However, in the case of photolyase, not only the ground-state redox properties of the FAD cofactor are exploited but also, and perhaps more importantly, its excited-state properties. In the catalytically active, fully reduced redox form, the FAD absorbs in the blue and near-UV ranges of visible light. Although there is no direct experimental evidence, it appears generally accepted that starting from the excited singlet state, the chromophore initiates a reductive cleavage of the two major DNA photodamages, cyclobutane pyrimidine dimers and (6-4) photoproducts, by short-distance electron transfer to the DNA lesion. Back electron transfer from the repaired DNA segment is believed to eventually restore the initial redox states of the cofactor and the DNA nucleobases, resulting in an overall reaction with net-zero exchanged electrons. Thus, the entire process represents a true catalytic cycle. Many biochemical and biophysical studies have been carried out to unravel the fundamentals of this unique mode of action. The work has culminated in the elucidation of the three-dimensional structure of the enzyme in 1995 that revealed remarkable details, such as the FAD-cofactor arrangement in an unusual U-shaped configuration. With the crystal structure of the enzyme at hand, research on photolyases did not come to an end but, for good reason, intensified: the geometrical structure of the enzyme alone is not sufficient to fully understand the enzyme's action on UV-damaged DNA. Much effort has therefore been invested to learn more about, for example, the geometry of the enzyme-substrate complex, and the mechanism and pathways of intra-enzyme and enzyme <-->DNA electron transfer. Many of the key results from biochemical and molecular biology characterizations of the enzyme or the enzyme-substrate complex have been summarized in a number of reviews. Complementary to these articles, this review focuses on recent biophysical studies of photoreactivation comprising work performed from the early 1990s until the present.
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Affiliation(s)
- Stefan Weber
- Institute of Experimental Physics, Free University Berlin, Arnimallee 14, 14195 Berlin, Germany.
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Cabrerizo FM, Lorente C, Vignoni M, Cabrerizo R, Thomas AH, Capparelli AL. Photochemical Behavior of 6-Methylpterin in Aqueous Solutions: Generation of Reactive Oxygen Species¶. Photochem Photobiol 2005. [DOI: 10.1562/2004-11-29-ra-383r.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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30
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Cabrerizo FM, Petroselli G, Lorente C, Capparelli AL, Thomas AH, Braun AM, Oliveros E. Substituent Effects on the Photophysical Properties of Pterin Derivatives in Acidic and Alkaline Aqueous Solutions. Photochem Photobiol 2005; 81:1234-40. [PMID: 16225380 DOI: 10.1562/2005-05-10-ra-522] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pterins are heterocyclic compounds with important biological functions, and most of them may exist in two acid-base forms in the pH range between 3 and 13 in aqueous solution. In this work, the photophysical properties of acid and basic forms of six compounds of the pterin family (6-hydroxymethylpterin [HPT], 6-methylpterin [MPT], 6,7-dimethylpterin [DPT], rhamnopterin [RPT], N-methylfolic acid [MFA], and pteroic acid [PA]) have been studied. The effects of the chemical nature of the substituents at position 6 of the pterin moiety and the effects of the pH on the absorption and emission properties are analyzed. The fluorescence characteristics (spectra, quantum yields, lifetimes) of these compounds have been investigated using the single-photon-counting technique. Results obtained for pterin derivatives containing small substituents with 1 carbon atom (HPT, MPT, DPT) and short hydrocarbon chain (4 carbon atoms) (RPT) are different from those found for pterin derivatives containing a p-aminobenzoic acid (PABA) moiety in the substituent (MFA and PA). Fluorescence quantum yields (Phi(F)) of the first group of compounds are relatively high (>/=0.4), whereas MFA and PA exhibit very small Phi(F) values (</=0.01).
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Affiliation(s)
- Franco M Cabrerizo
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4 (1900) La Plata, Argentina
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31
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Cabrerizo FM, Dántola ML, Thomas AH, Lorente C, Braun AM, Oliveros E, Capparelli AL. Photooxidation of Pterin in Aqueous Solutions: Biological and Biomedical Implications. Chem Biodivers 2004; 1:1800-11. [PMID: 17191817 DOI: 10.1002/cbdv.200490135] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Studies of the photochemical reactivity of pterin (= 2-aminopteridin-4(3H)-one; PT) in acidic (pH 5.0-6.0) and alkaline (pH 10.2-10.8) aqueous solutions have been performed. The photochemical reactions were followed by UV/VIS spectrophotometry, thin layer chromatography (TLC), high-performance liquid chromatography (HPLC), and an enzymatic method for H2O2 determination. PT is not light-sensitive in the absence of molecular oxygen, but it undergoes photooxidation in the presence of O2, yielding several nonpteridinic products. The quantum yields for PT disappearance were found to be 8.2 (+/-0.6) x 10(-4) and 1.2 (+/-0.2) x 10(-3) in acidic and alkaline media, respectively. H2O2 was detected and quantified in irradiated solutions of PT; and its importance from a biomedical point of view is discussed. The rate constant of the chemical reaction between singlet oxygen ((1)O2) and PT was determined to be 2.5 (+/-0.2) x 10(5) l mol(-1) s(-1) in alkaline medium, and the role of (1)O2 in the photooxidation of pterin was evaluated.
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Affiliation(s)
- Franco M Cabrerizo
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, CIC Casilla de Correo 16, Sucursal 4, 1900-La Plata, Argentina
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Volcov F, Goldman C. The efficiency of photolyase and indole complexes to repair DNA containing dimers of pyrimidine: A theoretical analysis of the electron transfer reactions. J Chem Phys 2004; 120:3381-6. [PMID: 15268493 DOI: 10.1063/1.1640612] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We analyze the effects of competing reactions to the efficiency of enzymatic splitting of pyrimidine dimers formed in DNA by the incidence of ultraviolet radiation. This is accomplished with the aid of a formula that expresses the efficiency of the repair in terms of parameters that regulate the reaction rates for primary and for back long-range electron transfers taking place in the process. Comparison of experimental data with estimations on account of this formula supports early conjectures in the literature that attribute the relative high performance of the enzymatic complexes of photolyase to its ability to suppress the back reaction.
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Affiliation(s)
- Flavia Volcov
- Instituto de Fisica, Universidade de Sao Paulo, CP 66318, 05315-970, Sao Paulo, Brazil
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MacFarlane AW, Stanley RJ. Cis-syn thymidine dimer repair by DNA photolyase in real time. Biochemistry 2003; 42:8558-68. [PMID: 12859203 DOI: 10.1021/bi034015w] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DNA photolyase (PL) is a monomeric flavoprotein that repairs cyclobutylpyrimidine dimers (CPDs) via photoinduced electron transfer from a reduced flavin adenine dinucleotide cofactor (FADH(-)) to the bound CPD. We have used subpicosecond UV transient absorption spectroscopy to measure the electron-transfer and repair kinetics of Anacystis nidulans DNA photolyase with dimeric and pentameric oligothymidine substrates. Here we show that the electron-transfer lifetime is 32 +/- 20 ps for the pentameric substrate. Repair of the carbon-carbon double bonds (C=C) in the CPD is initiated in approximately 60 ps, and bond scission appears to be completed by 1500 ps. This suggests that the repair of the two C=C bonds proceeds sequentially and that the first bond scission has a much lower activation barrier than the second. Our experiments also suggest that the semiquinone FADH(*) cofactor is not reduced to its catalytically active FADH(-) state by substrate after repair but remains in the semiquinone state. In contrast to the longer substrate, the dinucleotide substrate produced a mixture of kinetics representing bound and unbound substrate.
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Affiliation(s)
- Alexander W MacFarlane
- 201 Beury Hall, Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
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34
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Sancar A. Structure and function of DNA photolyase and cryptochrome blue-light photoreceptors. Chem Rev 2003; 103:2203-37. [PMID: 12797829 DOI: 10.1021/cr0204348] [Citation(s) in RCA: 932] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aziz Sancar
- Department of Biochemistry and Biophysics, Mary Ellen Jones Building, CB 7260, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
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35
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Thomas AH, Lorente C, Capparelli AL, Martínez CG, Braun AM, Oliveros E. Singlet oxygen (1deltag) production by pterin derivatives in aqueous solutions. Photochem Photobiol Sci 2003; 2:245-50. [PMID: 12713224 DOI: 10.1039/b209993d] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Six compounds of the pterin family (pterin, 6-carboxypterin, 6-formylpterin, folic acid, biopterin and neopterin) have been investigated for their efficiencies of singlet oxygen (O2(1deltag)) production and quenching in aqueous solutions. The quantum yields of 1O2 production (phidelta) have been determined by measurements of the 1O2 luminescence in the near-infrared (1270 nm) upon continuous excitation of the sensitizer. Under our experimental conditions, all studied compounds (except folic acid) are relatively efficient 1O2 sensitizers with phidelta values of up to 0.47. Results show that the nature of the substituent at position 6 on the pterin moiety, as well as the pH, affect considerably the capacity of pterins to produce 1O2. All compounds investigated are efficient 1O2 quenchers: the rate constant of 1O2 total quenching (kt) by folic acid (3.0(+/- 0.3) x 10(7) M(-1) s(-1)) is one order of magnitude larger than those for the other pterin derivatives investigated (1.4(+/- 0.1) x 10(6) M(-1) s(-1) to 2.9(+/- 0.3) x 10(6) M(-1) s(-1)).
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Affiliation(s)
- Andrés H Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Universidad Nacional de, La Plata, Casilla de Correo 16, Sucursal 4 (1900) La Plata, Argentina
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Salvatore P, Bucci C, Pagliarulo C, Tredici M, Colicchio R, Cantalupo G, Bardaro M, Del Giudice L, Massardo DR, Lavitola A, Bruni CB, Alifano P. Phenotypes of a naturally defective recB allele in Neisseria meningitidis clinical isolates. Infect Immun 2002; 70:4185-95. [PMID: 12117927 PMCID: PMC128164 DOI: 10.1128/iai.70.8.4185-4195.2002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neisseria meningitidis strains belonging to the hypervirulent lineage ET-37 and several unrelated strains are extremely UV sensitive. The phenotype is consequent to the presence of a nonfunctional recB(ET-37) allele carrying multiple missense mutations. Phenotypic analysis has been performed with congenic meningococcal strains harboring either the wild-type recB allele or the recB(ET-37) allele. Congenic recB(ET-37) meningococci, in addition to being sensitive to UV, were defective both in repair of DNA lesions induced by UV treatment and, partially, in recombination-mediated transformation. Consistently, the wild-type, but not the recB(ET-37), allele was able to complement the Escherichia coli recB21 mutation to UV resistance and proficiency in recombination. recB(ET-37) meningococci did not exhibit higher frequencies of spontaneous mutation to rifampin resistance than recB-proficient strains. However, mutation rates were enhanced following UV treatment, a phenomenon not observed in the recB-proficient counterpart. Interestingly, the results of PCR-based assays demonstrated that the presence of the recB(ET-37) allele considerably increased the frequency of recombination at the pilin loci. The main conclusion that can be drawn is that the presence of the defective recB(ET-37) allele in N. meningitidis isolates causes an increase in genetic diversity, due to an ineffective RecBCD-dependent DNA repair and recombination pathway, and an increase in pilin antigenic variation.
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Affiliation(s)
- Paola Salvatore
- Dipartimento di Biologia e Patologia Cellulare e Molecolare L. Califano, Università di Napoli Federico II, and Centro di Endocrinologia ed Oncologia Sperimentale G. Salvatore, Consiglio Nazionale delle Ricerche, 80131 Naples, Italy
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37
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Koponen PS, Kukkonen JVK. Effects of bisphenol A and artificial UVB radiation on the early development of Rana temporaria. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2002; 65:947-959. [PMID: 12133238 DOI: 10.1080/00984100290071180] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ultraviolet-B (UVB) radiation is one environmental factor that may act in concert with other stressors, such as xenobiotics, to produce adverse effect on amphibian populations. Embryos (< 24 h old) of the common frog (Rana temporaria) were exposed to four concentrations (0, 10, 100, or 1000 microg/L) of bisphenol A (BPA), with and without ultraviolet-B (UVB) radiation, for 20 d in the laboratory. Throughout the experiment the biologically effective daily UVB dose, calculated with Setlow's DNA action spectrum, was 2.80 kJ m(-2). UVB radiation as such did not have any significant effect on frog embryos. However, a BPA treatment of 1000 microg/L had a significant effect on embryos in both the UVB and no-UVB treatments, with the effect being greater with UVB. UVB produced a significant decrease in survival in the newly hatched frog larvae at all BPA concentrations. These results demonstrate that simultaneous exposure to these two stress factors is more harmful to R. temporaria larvae than exposure to one stressor alone.
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Affiliation(s)
- Petri S Koponen
- Laboratory of Aquatic Ecology and Ecotoxicology, Department of Biology, University of Joensuu, Joensuu, Finland.
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38
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Thomas AH, Lorente C, Capparelli AL, Pokhrel MR, Braun AM, Oliveros E. Fluorescence of pterin, 6-formylpterin, 6-carboxypterin and folic acid in aqueous solution: pH effects. Photochem Photobiol Sci 2002; 1:421-6. [PMID: 12856711 DOI: 10.1039/b202114e] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Steady-state and time-resolved studies have been performed on four compounds of the pterin family (pterin, 6-carboxypterin, 6-formylpterin and folic acid) in aqueous solution, using the single photon counting technique. The fluorescence characteristics (spectra, quantum yields, lifetimes) of these compounds and their dependence on the pH have been investigated. Most pterins can exist in two acid-base forms over the pH range between 3 and 13. Emission spectra and excitation spectra were obtained for both forms of each compound studied. Fluorescence quantum yields (phi(F)) in acidic and basic media were measured. The phi(F) of folic acid (< 0.005 in both media) is very low compared to those of pterin (0.27 in basic media and 0.33 in acidic media), 6-carboxypterin (0.18 in basic media and 0.28 in acidic media) and 6-formylpterin (0.07 in basic media and 0.12 in acidic media). The variation in integrated fluorescence intensity and fluorescence lifetimes (tau(F)) was analysed as a function of pH. Dynamic quenching by OH- was observed and the corresponding bimolecular rate constants for quenching of fluorescence (k(q)) were calculated. The reported values for k(q) (M(-1) s(-1)) are 3.6 x 10(9), 1.9 x 10(9) and 1.1 x 10(10) M(-1) s(-1) for pterin, 6-carboxypterin and 6-formylpterin, respectively.
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Affiliation(s)
- Andrés H Thomas
- Instituto de Investigaciones Fisicoquímica Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4 (1900) La Plata, Argentina
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39
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Lu CY, Yao SD, Lin NY. Photooxidation of 2′-deoxyguanosine 5′-monophosphate (dGMP) by flavin adenine dinucleotide (FAD) via electron transfer: a laser photolysis study. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)01092-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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40
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Kinetic observation of rapid electron transfer between pyrimidine electron adducts and sensitizers of riboflavin, flavin adenine dinucleotide (FAD) and chloranil: a pulse radiolysis study. Radiat Phys Chem Oxf Engl 1993 2000. [DOI: 10.1016/s0969-806x(00)00181-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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41
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Lee E, Medvedev ES, Stuchebrukhov AA. Calculation of Quantum Parameters for Nonadiabatic Redox Reactions. Application to Photoreduction of Flavin in DNA Photolyase. J Phys Chem B 2000. [DOI: 10.1021/jp000167e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- EunJoo Lee
- Department of Chemistry, University of California, Davis, California 95616, and Institute of Chemical Physics Problems, Russian Academy of Sciences, 142432 Chernogolovka, Moscow, Russia
| | - Emile S. Medvedev
- Department of Chemistry, University of California, Davis, California 95616, and Institute of Chemical Physics Problems, Russian Academy of Sciences, 142432 Chernogolovka, Moscow, Russia
| | - Alexei A. Stuchebrukhov
- Department of Chemistry, University of California, Davis, California 95616, and Institute of Chemical Physics Problems, Russian Academy of Sciences, 142432 Chernogolovka, Moscow, Russia
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42
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Volk M, Gilch P, Kompa C, Haselsberger R, Härter P, Stöckl M, Scherer W, Latzel K, Michel-Beyerle ME. Carbonyl Spectator Bonds as Sensitive Sensors for Charge Transfer Reactions on the Femtosecond Time Scale. J Phys Chem A 2000. [DOI: 10.1021/jp000575i] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martin Volk
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Peter Gilch
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Christian Kompa
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Reinhard Haselsberger
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Peter Härter
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Marco Stöckl
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Wolfgang Scherer
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Klaus Latzel
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
| | - Maria-Elisabeth Michel-Beyerle
- Institut für Physikalische und Theoretische Chemie, and Institut für Anorganische Chemie, Technische Universität München, D-85748 Garching, Germany
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43
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Ito T, Shinohara H, Hatta H, Fujita SI, Nishimoto SI. Radiation-Induced and Photosensitized Splitting of C5−C5‘-Linked Dihydrothymine Dimers. 2. Conformational Effects on the Reductive Splitting Mechanism. J Phys Chem A 2000. [DOI: 10.1021/jp9939367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Takeo Ito
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, and Research Institute of Advanced Technology, University of Osaka Prefecture, Osaka 599-8231, Japan
| | - Hideki Shinohara
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, and Research Institute of Advanced Technology, University of Osaka Prefecture, Osaka 599-8231, Japan
| | - Hiroshi Hatta
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, and Research Institute of Advanced Technology, University of Osaka Prefecture, Osaka 599-8231, Japan
| | - Shin-ichi Fujita
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, and Research Institute of Advanced Technology, University of Osaka Prefecture, Osaka 599-8231, Japan
| | - Sei-ich Nishimoto
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, and Research Institute of Advanced Technology, University of Osaka Prefecture, Osaka 599-8231, Japan
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44
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Generation and photosensitization properties of the oxidized radical of riboflavin: a laser flash photolysis study. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1999. [DOI: 10.1016/s1011-1344(99)00111-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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45
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A cyclic intermediate of the splitting reaction of cyclobutane-type pyrimidine dimer cation radicals. A computational finding as challenge for experimental techniques. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0166-1280(98)00629-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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46
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Rak J, Voityuk AA, Michel-Beyerle ME, Rösch N. Effect of Proton Transfer on the Anionic and Cationic Pathways of Pyrimidine Photodimer Cleavage. A Computational Study. J Phys Chem A 1999. [DOI: 10.1021/jp9901545] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Janusz Rak
- Institut für Physikalische and Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
| | - Alexander A. Voityuk
- Institut für Physikalische and Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
| | | | - Notker Rösch
- Institut für Physikalische and Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
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47
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Aoki S, Sugimura C, Kimura E. Efficient Inhibition of Photo[2 + 2]cycloaddition of Thymidilyl(3‘−5‘)thymidine and Promotion of Photosplitting of the cis-syn-Cyclobutane Thymine Dimer by Dimeric Zinc(II)−Cyclen Complexes Containing m- and p-Xylyl Spacers. J Am Chem Soc 1998. [DOI: 10.1021/ja981788c] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shin Aoki
- Contribution from the Department of Medicinal Chemistry, School of Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Chizuyo Sugimura
- Contribution from the Department of Medicinal Chemistry, School of Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
| | - Eiichi Kimura
- Contribution from the Department of Medicinal Chemistry, School of Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan
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48
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Rak J, Voityuk AA, Rösch N. Splitting of Cyclobutane-Type Uracil Dimer Cation Radicals. Hartree−Fock, MP2, and Density Functional Studies. J Phys Chem A 1998. [DOI: 10.1021/jp981665e] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Janusz Rak
- Lehrstuhl für Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
| | - Alexander A. Voityuk
- Lehrstuhl für Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
| | - Notker Rösch
- Lehrstuhl für Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
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49
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Epple R, Carell T. Charakterisierung des Energietransfers in DNA-Photolyasen vom Typ II mit Flavin und Desazaflavin enthaltenden Modellverbindungen. Angew Chem Int Ed Engl 1998. [DOI: 10.1002/(sici)1521-3757(19980403)110:7<986::aid-ange986>3.0.co;2-d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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50
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Voityuk AA, Rösch N. Ab Initio Study on the Structure and Splitting of the Uracil Dimer Anion Radical. J Phys Chem A 1997. [DOI: 10.1021/jp971187s] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander A. Voityuk
- Institut für Physikalische and Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
| | - Notker Rösch
- Institut für Physikalische and Theoretische Chemie, Technische Universität München, D-85747 Garching, Germany
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