1
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Janicki MJ, Szabla R, Šponer J, Góra RW. Photoinduced water-chromophore electron transfer causes formation of guanosine photodamage. Phys Chem Chem Phys 2022; 24:8217-8224. [PMID: 35319053 DOI: 10.1039/d2cp00801g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UV-induced photolysis of aqueous guanine nucleosides produces 8-oxo-guanine and Fapy-guanine, which can induce various types of cellular malfunction. The mechanistic rationale underlying photodestructive processes of guanine nucleosides is still largely obscure. Here, we employ accurate quantum chemical calculations and demonstrate that an excited-state non-bonding interaction of guanosine and a water molecule facilitates the electron-driven proton transfer process from water to the chromophore fragment. This subsequently allows for the formation of a crucial intermediate, namely guanosine photohydrate. Further (photo)chemical reactions of this intermediate lead to the known products of guanine photodamage.
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Affiliation(s)
- Mikołaj J Janicki
- Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Rafał Szabla
- Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Robert W Góra
- Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
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2
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Krul SE, Hoehn SJ, Feierabend KJ, Crespo-Hernández CE. Excited state dynamics of 7-deazaguanosine and guanosine 5'-monophosphate. J Chem Phys 2021; 154:075103. [PMID: 33607894 DOI: 10.1063/5.0038123] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Minor structural modifications to the DNA and RNA nucleobases have a significant effect on their excited state dynamics and electronic relaxation pathways. In this study, the excited state dynamics of 7-deazaguanosine and guanosine 5'-monophosphate are investigated in aqueous solution and in a mixture of methanol and water using femtosecond broadband transient absorption spectroscopy following excitation at 267 nm. The transient spectra are collected using photon densities that ensure no parasitic multiphoton-induced signal from solvated electrons. The data can be fit satisfactorily using a two- or three-component kinetic model. By analyzing the results from steady-state, time-resolved, computational calculations, and the methanol-water mixture, the following general relaxation mechanism is proposed for both molecules, Lb → La → 1πσ*(ICT) → S0, where the 1πσ*(ICT) stands for an intramolecular charge transfer excited singlet state with significant πσ* character. In general, longer lifetimes for internal conversion are obtained for 7-deazaguanosine compared to guanosine 5'-monophosphate. Internal conversion of the 1πσ*(ICT) state to the ground state occurs on a similar time scale of a few picoseconds in both molecules. Collectively, the results demonstrate that substitution of a single nitrogen atom for a methine (C-H) group at position seven of the guanine moiety stabilizes the 1ππ* Lb and La states and alters the topology of their potential energy surfaces in such a way that the relaxation dynamics in 7-deazaguanosine are slowed down compared to those in guanosine 5'-monophosphate but not for the internal conversion of 1πσ*(ICT) state to the ground state.
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Affiliation(s)
- Sarah E Krul
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Sean J Hoehn
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Karl J Feierabend
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
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3
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Marsili E, Prlj A, Curchod BFE. Caveat when using ADC(2) for studying the photochemistry of carbonyl-containing molecules. Phys Chem Chem Phys 2021; 23:12945-12949. [PMID: 34085679 PMCID: PMC8207513 DOI: 10.1039/d1cp02185k] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 05/28/2021] [Indexed: 12/21/2022]
Abstract
Several electronic-structure methods are available to study the photochemistry and photophysics of organic molecules. Among them, ADC(2) stands as a sweet spot between computational efficiency and accuracy. As a result, ADC(2) has recently seen its number of applications booming, in particular to unravel the deactivation pathways and photodynamics of organic molecules. Despite this growing success, we demonstrate here that care has to be taken when studying the nonradiative pathways of carbonyl-containing molecules, as ADC(2) appears to suffer from a systematic flaw.
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Affiliation(s)
| | - Antonio Prlj
- Department of Chemistry, Durham University, Durham DH1 3LE, UK.
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4
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Zhao L, Zhou P, Liu X, Zheng H, Zhan K, Luo J, Liu B. Theoretical studies of the ultrafast deactivation mechanism of 8-oxo-guanine on the S 1 and S 2 electronic states in gas phase. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 244:118884. [PMID: 32898726 DOI: 10.1016/j.saa.2020.118884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/18/2020] [Accepted: 08/22/2020] [Indexed: 06/11/2023]
Abstract
The 8-oxo-deoxyguanosine is the most abundant specie of the DNA oxidative damage. Despite the deleterious effects such as gene mutation it may cause, the 8-oxodG was also reported to have beneficial effect such as repairing the nearby cyclobutane pyrimidine dimer (CPD) after photoexcitation. Due to its strong biological relevance, the photoinduced excited state dynamics behavior of 8-oxo-deoxyguanosine is of particular interest. In this work, a theoretical investigation by combination of complete active space self-consistent field (CASSCF) ab initio calculations and on-the-fly nonadiabatic dynamics simulations are implemented to provide intrinsic deactivation mechanism of its free base 8-oxoguanine after being excited to the S1 and S2 states. Two minimum energy conical intersections (MECIs) characterized by the C3-puckered motion with attractive chiral character are located, which contribute appreciably to the S1 state deactivation process. When the system is being excited to the S2 state directly, a S2 → S1 → S0 two-step decay pattern is proposed. A nearly planar S2/S1 intersection plays a significant role in the S2 → S1 decay process. The subsequent S1 state relaxation process is also dominated by the C3-puckered deformation motion. One decay time is estimated to be 704 fs, which compares well with the experimental observation of 0.9 ± 0.1 ps in solvents. Particular illustration is the fact that the MECIs configurations we located bear an exceptional resemblance with previous reported thymine, cytosine and guanine, suggesting that the current work could lend support for better understanding of the non-natural nucleobases and derivatives.
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Affiliation(s)
- Li Zhao
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China.
| | - Panwang Zhou
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266235, PR China
| | - Xiaoxu Liu
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Haixia Zheng
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Kaiyun Zhan
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Jianhui Luo
- Research Institute of Petroleum Exploration & Development (RIPED), PetroChina, Beijing 100083, PR China
| | - Bing Liu
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China.
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5
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Pepino AJ, Segarra-Martí J, Nenov A, Rivalta I, Improta R, Garavelli M. UV-induced long-lived decays in solvated pyrimidine nucleosides resolved at the MS-CASPT2/MM level. Phys Chem Chem Phys 2018; 20:6877-6890. [PMID: 29459916 DOI: 10.1039/c7cp08235e] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The most relevant 'dark' electronic excited states in DNA/RNA pyrimidine nucleosides are mapped in water employing hybrid MS-CASPT2/MM optimisations with explicit solvation and including the sugar. Conical intersections (CIs) between initially accessed bright 1ππ* and the lowest energy dark 1nπ* excited states, involving the lone pair localised on the oxygen and/or nitrogen atoms are characterised. They are found in the vicinities of the Franck-Condon (FC) region and are shown to facilitate non-adiabatic population transfer. The excited state population of the 1nOπ* state, localised in the carbonyl moiety on all pyrimidine nucleosides, is predicted to rapidly evolve to its minimum, displaying non-negligible potential energy barriers along its non-radiative decay, and accounting for the ps signal registered in pump-probe experiments as well as for an efficient population of the triplet state. Cytidine displays an additional 1nNπ* state localised in the N3 atom and that leads to its excited state minimum displaying large potential energy barriers in the pathway connecting to the CI with the ground state. Sugar-to-base hydrogen/proton transfer processes are assessed in solution for the first time, displaying a sizable barrier along its decay and thus being competitive with other slow decay channels in the ps and ns timescales. A unified deactivation scheme for the long-lived channels of pyrimidine nucleosides is delivered, where the 1nOπ* state is found to mediate the long-lived decay in the singlet manifold and act as the doorway for triplet population and thus accounting for the recorded phosphorescence and, more generally, for the transient/photoelectron spectral signals registered up to the ns timescale.
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Affiliation(s)
- Ana Julieta Pepino
- Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy.
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6
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Excited states dissociation dynamics of indole-x-carboxaldehyde (x = 4, 5, 6, 7): Theoretical and experimental study. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Ashwood B, Ortiz-Rodríguez LA, Crespo-Hernández CE. Photochemical relaxation pathways of S 6-methylthioinosine and O 6-methylguanosine in solution. Faraday Discuss 2018; 207:351-374. [PMID: 29372193 DOI: 10.1039/c7fd00193b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
S6-Methylthioinosine and O6-methylguanosine are byproducts resulting from the enzymatic reactions of sulfur-substituted prodrugs in cells and from the interaction of alkylating agents with cellular DNA, respectively. Their photochemistry has not been investigated, and it is currently unknown whether light absorption by these byproducts may pose any threat to the cell. In this contribution, their photoinduced processes upon absorption of UVB radiation are reported using broadband transient absorption spectroscopy. Plausible electronic relaxation mechanisms are proposed for both biological molecules, which are supported by steady-state absorption and emission measurements, and by singlet and triplet vertical excitation energies performed on a large subset of ground-state optimized conformational isomers in solution. The results are compared to the body of knowledge gathered in the scientific literature about the light-induced processes in the sulfur-substituted and canonical purine monomers. In particular, it is shown that S6-methylation decreases the rate to populate the lowest-energy triplet state and blueshifts the ground-state absorption spectrum compared to those for the sulfur-substituted prodrugs and for the 6-thioguanosine metabolite. Similarly, O6-methylation decreases the rate of internal conversion to the ground state observed in the guanine monomers by more than 10-fold in acetonitrile and 40-fold in aqueous solution, while it redshifts the ground-state absorption spectrum. Collectively, this investigation provides relevant new insights about the relationship between structural modifications of the purine chromophore and the electronic relaxation mechanisms in this important group of biological molecules.
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Affiliation(s)
- Brennan Ashwood
- Department of Chemistry, Center for Chemical Dynamics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA.
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8
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Szabla R, Góra RW, Šponer J. Ultrafast excited-state dynamics of isocytosine. Phys Chem Chem Phys 2018; 18:20208-18. [PMID: 27346684 DOI: 10.1039/c6cp01391k] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The alternative nucleobase isocytosine has long been considered as a plausible component of hypothetical primordial informational polymers. To examine this hypothesis we investigated the excited-state dynamics of the two most abundant forms of isocytosine in the gas phase (keto and enol). Our surface-hopping nonadiabatic molecular dynamics simulations employing the algebraic diagrammatic construction to the second order [ADC(2)] method for the electronic structure calculations suggest that both tautomers undergo efficient radiationless deactivation to the electronic ground state with time constants which amount to τketo = 182 fs and τenol = 533 fs. The dominant photorelaxation pathways correspond to ring-puckering (ππ* surface) and C[double bond, length as m-dash]O stretching/N-H tilting (nπ* surface) for the enol and keto forms respectively. Based on these findings, we infer that isocytosine is a relatively photostable compound in the gas phase and in these terms resembles biologically relevant nucleobases. The estimated S1 [radiolysis arrow - arrow with voltage kink] T1 intersystem crossing rate constant of 8.02 × 10(10) s(-1) suggests that triplet states might also play an important role in the overall excited-state dynamics of the keto tautomer. The reliability of ADC(2)-based surface-hopping molecular dynamics simulations was tested against multireference quantum-chemical calculations and the potential limitations of the employed ADC(2) approach are briefly discussed.
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Affiliation(s)
- Rafał Szabla
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic.
| | - Robert W Góra
- Department of Physical and Quantum Chemistry, Faculty of Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic. and CEITEC-Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
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9
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Šponer JE, Szabla R, Góra RW, Saitta AM, Pietrucci F, Saija F, Di Mauro E, Saladino R, Ferus M, Civiš S, Šponer J. Prebiotic synthesis of nucleic acids and their building blocks at the atomic level - merging models and mechanisms from advanced computations and experiments. Phys Chem Chem Phys 2018; 18:20047-66. [PMID: 27136968 DOI: 10.1039/c6cp00670a] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The origin of life on Earth is one of the most fascinating questions of contemporary science. Extensive research in the past decades furnished diverse experimental proposals for the emergence of first informational polymers that could form the basis of the early terrestrial life. Side by side with the experiments, the fast development of modern computational chemistry methods during the last 20 years facilitated the use of in silico modelling tools to complement the experiments. Modern computations can provide unique atomic-level insights into the structural and electronic aspects as well as the energetics of key prebiotic chemical reactions. Many of these insights are not directly obtainable from the experimental techniques and the computations are thus becoming indispensable for proper interpretation of many experiments and for qualified predictions. This review illustrates the synergy between experiment and theory in the origin of life research focusing on the prebiotic synthesis of various nucleic acid building blocks and on the self-assembly of nucleotides leading to the first functional oligonucleotides.
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Affiliation(s)
- Judit E Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic. and CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Rafał Szabla
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic.
| | - Robert W Góra
- Theoretical Chemistry Group, Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - A Marco Saitta
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, CNRS, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, UMR 7590, F-75005 Paris, France
| | - Fabio Pietrucci
- Sorbonne Universités, Université Pierre et Marie Curie Paris 6, CNRS, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, UMR 7590, F-75005 Paris, France
| | - Franz Saija
- CNR-IPCF, Viale Ferdinando Stagno d'Alcontres 37, 98158 Messina, Italy
| | - Ernesto Di Mauro
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", "Sapienza" Università di Roma, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - Raffaele Saladino
- Dipartimento di Scienze Ecologiche e Biologiche Università della Tuscia, Via San Camillo De Lellis, 01100 Viterbo, Italy
| | - Martin Ferus
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague 8, Czech Republic
| | - Svatopluk Civiš
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-182 23 Prague 8, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, CZ-612 65 Brno, Czech Republic. and CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
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10
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Prlj A, Vannay L, Corminboeuf C. Fluorescence Quenching in BODIPY Dyes: The Role of Intramolecular Interactions and Charge Transfer. Helv Chim Acta 2017. [DOI: 10.1002/hlca.201700093] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Antonio Prlj
- Institut des Sciences et Ingénierie Chimiques; École polytechnique fédérale de Lausanne; CH-1015 Lausanne
| | - Laurent Vannay
- Institut des Sciences et Ingénierie Chimiques; École polytechnique fédérale de Lausanne; CH-1015 Lausanne
| | - Clemence Corminboeuf
- Institut des Sciences et Ingénierie Chimiques; École polytechnique fédérale de Lausanne; CH-1015 Lausanne
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11
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Pepino AJ, Segarra-Martí J, Nenov A, Improta R, Garavelli M. Resolving Ultrafast Photoinduced Deactivations in Water-Solvated Pyrimidine Nucleosides. J Phys Chem Lett 2017; 8:1777-1783. [PMID: 28346789 DOI: 10.1021/acs.jpclett.7b00316] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
For the first time, ultrafast deactivations of photoexcited water-solvated pyrimidine nucleosides are mapped employing hybrid QM(CASPT2)/MM(AMBER) optimizations that account for explicit solvation, sugar effects, and dynamically correlated potential energy surfaces. Low-energy S1/S0 ring-puckering and ring-opening conical intersections (CIs) are suggested to drive the ballistic coherent subpicosecond (<200 fs) decays observed in each pyrimidine, the energetics controlling this processes correlating with the lifetimes observed. A second bright 1π2π* state, promoting excited-state population branching and leading toward a third CI with the ground state, is proposed to be involved in the slower ultrafast decay component observed in Thd/Cyd. The transient spectroscopic signals of the competitive deactivation channels are computed for the first time. A general unified scheme for ultrafast deactivations, spanning the sub- to few-picosecond time domain, is eventually delivered, with computed data that matches the experiments and elucidates the intrinsic photoprotection mechanism in solvated pyrimidine nucleosides.
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Affiliation(s)
- Ana Julieta Pepino
- Dipartimento di Chimica Industriale "Toso Montanari" Viale del Risorgimento, 4, 40136 Bologna, Italy
| | - Javier Segarra-Martí
- Laboratoire de Chimie UMR 5182, Université Lyon, ENS de Lyon, CNRS, Université Lyon 1 , F-69342 Lyon, France
| | - Artur Nenov
- Dipartimento di Chimica Industriale "Toso Montanari" Viale del Risorgimento, 4, 40136 Bologna, Italy
| | - Roberto Improta
- Istituto di Biostrutture e Bioimmagini CNR , Via Mezzocannone 16, I-80134 Napoli, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale "Toso Montanari" Viale del Risorgimento, 4, 40136 Bologna, Italy
- Laboratoire de Chimie UMR 5182, Université Lyon, ENS de Lyon, CNRS, Université Lyon 1 , F-69342 Lyon, France
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12
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Wu X, Karsili TNV, Domcke W. Role of Electron-Driven Proton-Transfer Processes in the Ultrafast Deactivation of Photoexcited Anionic 8-oxoGuanine-Adenine and 8-oxoGuanine-Cytosine Base Pairs. Molecules 2017; 22:molecules22010135. [PMID: 28098833 PMCID: PMC6155867 DOI: 10.3390/molecules22010135] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 12/28/2016] [Accepted: 01/10/2017] [Indexed: 11/16/2022] Open
Abstract
It has been reported that 8-oxo-7,8-dihydro-guanosine (8-oxo-G), which is the main product of oxidative damage of DNA, can repair cyclobutane pyrimidine dimer (CPD) lesions when incorporated into DNA or RNA strands in proximity to such lesions. It has therefore been suggested that the 8-oxo-G nucleoside may have been a primordial precursor of present-day flavins in DNA or RNA repair. Because the electron transfer leading to the splitting of a thymine-thymine pair in a CPD lesion occurs in the photoexcited state, a reasonably long excited-state lifetime of 8-oxo-G is required. The neutral (protonated) form of 8-oxo-G exhibits a very short (sub-picosecond) intrinsic excited-state lifetime which is unfavorable for repair. It has therefore been argued that the anionic (deprotonated) form of 8-oxo-G, which exhibits a much longer excited-state lifetime, is more likely to be a suitable cofactor for DNA repair. Herein, we have investigated the exited-state quenching mechanisms in the hydrogen-bonded complexes of deprotonated 8-oxo-G- with adenine (A) and cytosine (C) using ab initio wave-function-based electronic-structure calculations. The calculated reaction paths and potential-energy profiles reveal the existence of barrierless electron-driven inter-base proton-transfer reactions which lead to low-lying S₁/S₀ conical intersections. The latter can promote ultrafast excited-state deactivation of the anionic base pairs. While the isolated deprotonated 8-oxo-G- nucleoside may have been an efficient primordial repair cofactor, the excited states of the 8-oxo-G--A and 8-oxo-G--C base pairs are likely too short-lived to be efficient electron-transfer repair agents.
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Affiliation(s)
- Xiuxiu Wu
- Department of Chemistry, Technische Universitat Munchen, Lichtenbergstr. 4, Garching D-85747, Germany.
| | - Tolga N V Karsili
- Department of Chemistry, Temple University, 130 Beury Hall, 1901 N. 13th St., Philadelphia, PA 19122, USA.
| | - Wolfgang Domcke
- Department of Chemistry, Technische Universitat Munchen, Lichtenbergstr. 4, Garching D-85747, Germany.
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13
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Hu D, Liu YF, Sobolewski AL, Lan Z. Nonadiabatic dynamics simulation of keto isocytosine: a comparison of dynamical performance of different electronic-structure methods. Phys Chem Chem Phys 2017; 19:19168-19177. [DOI: 10.1039/c7cp01732d] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Different reaction channels are obtained in the nonadiabatic dynamics simulations of isocytosine at CASSCF and ADC(2) levels.
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Affiliation(s)
- Deping Hu
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- People's Republic of China
| | - Yan Fang Liu
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- People's Republic of China
| | | | - Zhenggang Lan
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- People's Republic of China
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14
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Prlj A, Fabrizio A, Corminboeuf C. Rationalizing fluorescence quenching in meso-BODIPY dyes. Phys Chem Chem Phys 2016; 18:32668-32672. [DOI: 10.1039/c6cp06799a] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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15
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Szabla R, Góra RW, Janicki M, Šponer J. Photorelaxation of imidazole and adenine via electron-driven proton transfer along H2O wires. Faraday Discuss 2016; 195:237-251. [DOI: 10.1039/c6fd00131a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photochemically created πσ* states were classified among the most prominent factors determining the ultrafast radiationless deactivation and photostability of many biomolecular building blocks. In the past two decades, the gas phase photochemistry of πσ* excitations was extensively investigated and was attributed to N–H and O–H bond fission processes. However, complete understanding of the complex photorelaxation pathways of πσ* states in the aqueous environment was very challenging, owing to the direct participation of solvent molecules in the excited-state deactivation. Here, we present non-adiabatic molecular dynamics simulations and potential energy surface calculations of the photoexcited imidazole–(H2O)5 cluster using the algebraic diagrammatic construction method to the second-order [ADC(2)]. We show that electron driven proton transfer (EDPT) along a wire of at least two water molecules may lead to the formation of a πσ*/S0 state crossing, similarly to what we suggested for 2-aminooxazole. We expand on our previous findings by direct comparison of the imidazole–(H2O)5 cluster to non-adiabatic molecular dynamics simulations of imidazole in the gas phase, which reveal that the presence of water molecules extends the overall excited-state lifetime of the chromophore. To embed the results in a biological context, we provide calculations of potential energy surface cuts for the analogous photorelaxation mechanism present in adenine, which contains an imidazole ring in its structure.
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Affiliation(s)
- Rafał Szabla
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- Brno
- Czech Republic
| | - Robert W. Góra
- Department of Physical and Quantum Chemistry
- Faculty of Chemistry
- Wrocław University of Technology
- 50-370 Wrocław
- Poland
| | - Mikołaj Janicki
- Department of Physical and Quantum Chemistry
- Faculty of Chemistry
- Wrocław University of Technology
- 50-370 Wrocław
- Poland
| | - Jiří Šponer
- Institute of Biophysics
- Academy of Sciences of the Czech Republic
- Brno
- Czech Republic
- CEITEC–Central European Institute of Technology
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