1
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Bin Mohd Yusof MS, Siow JX, Yang N, Chan WX, Loh ZH. Spectroscopic observation and ultrafast coherent vibrational dynamics of the aqueous phenylalanine radical. Phys Chem Chem Phys 2022; 24:2800-2812. [PMID: 35048090 DOI: 10.1039/d1cp04326a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The phenylalanine radical (Phe˙) has been proposed to mediate biological electron transport (ET) and exhibit long-lived electronic coherences following attosecond photoionization. However, the coupling of ultrafast structural reorganization to the oxidation/ionization of biomolecules such as phenylalanine remains unexplored. Moreover, studies of ET involving Phe˙ are hindered by its hitherto unobserved electronic spectrum. Here, we report the spectroscopic observation and coherent vibrational dynamics of aqueous Phe˙, prepared by sub-6 fs photodetachment of phenylalaninate anions. Sub-picosecond transient absorption spectroscopy reveals the ultraviolet absorption signature of Phe˙. Ultrafast structural reorganization drives coherent vibrational motion involving nine fundamental frequencies and one overtone. DFT calculations rationalize the absence of the decarboxylation reaction, a photodegradation pathway previously identified for Phe˙. Our findings guide the interpretation of future attosecond experiments aimed at elucidating coherent electron motion in photoionized aqueous biomolecules and pave way for the spectroscopic identification of Phe˙ in studies of biological ET.
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Affiliation(s)
- Muhammad Shafiq Bin Mohd Yusof
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Jing Xuan Siow
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Ningchen Yang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Wei Xin Chan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Zhi-Heng Loh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
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2
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Usabiaga I, Camiruaga A, Calabrese C, Veloso A, D'mello VC, Wategaonkar S, Fernández JA. Exploration of the theobromine-water dimer: comparison with DNA microhydration. Phys Chem Chem Phys 2020; 22:15759-15768. [PMID: 32627788 DOI: 10.1039/d0cp02397c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Understanding the molecular basis of the appearance of life on Earth is an exciting research field. Many factors may have influenced the election of the molecules used by living beings and evolution may have modified those original compounds. In an attempt to understand the role played by intermolecular interactions in the election of CGAT as the alphabet of life, we present here a thorough experimental and computational study on the interaction of theobromine with water. Theobromine is a xanthine derivative, structurally related to the nucleobases, and also present in many living beings. The experimental results demonstrate that the most stable isomer of theobromine-water was formed and detected in supersonic expansions. This isomer very well resembles the structure of the dimers between nucleobases and water, offering similar values of binding energy. A comparison between the results obtained for theobromine-water with those reported in the literature for monohydrates of nucleobases is also offered.
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Affiliation(s)
- Imanol Usabiaga
- Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), 48940, Leioa, Spain.
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3
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Jena NR. Electron and hole interactions with P, Z, and P:Z and the formation of mutagenic products by proton transfer reactions. Phys Chem Chem Phys 2020; 22:919-931. [DOI: 10.1039/c9cp05367k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Z would act as an electron acceptor and P would capture a hole in the unnatural DNA. The latter process would produce mutagenic products via a proton transfer reaction.
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Affiliation(s)
- N. R. Jena
- Discipline of Natural Sciences
- Indian Institute of Information Technology, Design, and Manufacturing
- Jabalpur-482005
- India
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4
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Zhang Y, Xie P, Yang S, Han K. Ionization and Electron Attachment for Nucleobases in Water. J Phys Chem B 2019; 123:1237-1247. [DOI: 10.1021/acs.jpcb.8b09435] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Yan Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, China
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao, Binhai Road 72, Qingdao 266237, China
| | - Peng Xie
- School of Chemistry & Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Songqiu Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, China
| | - Keli Han
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, China
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5
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Wei SC, Ho JW, Yen HC, Shi HQ, Cheng LH, Weng CN, Chou WK, Chiu CC, Cheng PY. Ultrafast Excited-State Dynamics of Hydrogen-Bonded Cytosine Microsolvated Clusters with Protic and Aprotic Polar Solvents. J Phys Chem A 2018; 122:9412-9425. [PMID: 30452255 DOI: 10.1021/acs.jpca.8b09526] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microsolvation effects on the ultrafast excited-state deactivation dynamics of cytosine (Cy) were studied in hydrogen-bonded Cy clusters with protic and aprotic solvents using mass-resolved femtosecond pump-probe ionization spectroscopy. Two protic solvents, water (H2O) and methanol (MeOH), and one aprotic solvent, tetrahydrofuran (THF), were investigated, and transients of Cy·(H2O)1-6, Cy·(MeOH)1-3, and Cy·THF microsolvated clusters produced in supersonic expansions were measured. With the aid of electronic structure calculations, we assigned the observed dynamics to the low-energy isomers of various Cy clusters and discussed the microsolvation effect on the excited-state deactivation dynamics. With the protic solvents only the microsolvated clusters of Cy keto tautomer were observed. The observed decay time constants of Cy·(H2O) n are 0.5 ps for n = 1 and ∼0.2-0.25 ps for n = 2-6. For Cy·(MeOH) n clusters, the decay time constant for n = 1 cluster is similar to that of the Cy monohydrate, but for n = 2 and 3 the decays are about a factor of 2 slower than the corresponding microhydrates. With the aprotic solvent, THF, hydrogen-bonded complexes of both keto and enol tautomers are present in the beam. The keto-Cy·THF shows a decay similar to that of the keto-Cy monomer, whereas the enol-Cy·THF exhibits a 2-fold slower decay than the enol-Cy monomer, suggesting an increase in the barrier to excited-state deactivation upon binding of one THF molecule to the enol form of Cy.
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Affiliation(s)
- Shih-Chun Wei
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Jr-Wei Ho
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Hung-Chien Yen
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Hui-Qi Shi
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Li-Hao Cheng
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Chih-Nan Weng
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Wei-Kuang Chou
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Chih-Chung Chiu
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
| | - Po-Yuan Cheng
- Department of Chemistry , National Tsing Hua University , Hsinchu , Taiwan 30043 , Republic of China
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6
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Peng HL, Callender R. Mechanism for Fluorescence Quenching of Tryptophan by Oxamate and Pyruvate: Conjugation and Solvation-Induced Photoinduced Electron Transfer. J Phys Chem B 2018; 122:6483-6490. [PMID: 29860828 DOI: 10.1021/acs.jpcb.8b02433] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxamate and pyruvate are isoelectronic molecules. They both quench tryptophan fluorescence with Stern-Volmer constants of 16 and 20 M-1, respectively, which are comparable to that of arcrylamide, a commonly used probe for protein structure. On the other hand, it is well known that neither the carboxylate group of these molecules nor the amide group is a good quencher. To find the mechanism of the quenching by oxamate and pyruvate, density functional theory computations with a polarizable continuum model, solvation based on density, and explicit waters, were performed. Results indicate that both molecules can be an electron acceptor via photoinduced electron transfer. There are two requirements. First, the carboxylate and amide moieties must be in direct contact to bring about noticeable quenching. The conjugation between the amide (or the keto) group and the carboxylate group leads to a lower π* orbital, which is the lowest unoccupied molecular orbital (LUMO), and can then accept an electron from the excited tryptophan. Second, since oxamate and pyruvate ions have high electron density, hydrogen bonds with waters, which can be simulated by an explicit water model, are essential. Their LUMO energies are strongly influenced by water in aqueous solution. The above findings demonstrate how tryptophan fluorescence gets quenched in aqueous solution. The findings may be important in dealing with those problems where frontier orbitals are considered, especially with molecules having high electron density.
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Affiliation(s)
- Huo-Lei Peng
- Department of Biochemistry , Albert Einstein College of Medicine , New York , New York 10461 , United States
| | - Robert Callender
- Department of Biochemistry , Albert Einstein College of Medicine , New York , New York 10461 , United States
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7
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Intermolecular interaction in nucleobases and dimethyl sulfoxide/water molecules: A DFT, NBO, AIM and NCI analysis. J Mol Graph Model 2017; 78:48-60. [DOI: 10.1016/j.jmgm.2017.09.022] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/27/2017] [Accepted: 09/28/2017] [Indexed: 01/05/2023]
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8
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9
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Zhang R, Bu Y. Bifurcate localization modes of excess electron in aqueous Ca(2+)amide solution revealed by ab initio molecular dynamics simulation: towards hydrated electron versus hydrated amide anion. Phys Chem Chem Phys 2016; 18:18868-79. [PMID: 27351489 DOI: 10.1039/c6cp03552c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, we conduct ab initio molecular dynamics simulations on the localization dynamics of an excess electron (EE) in acetamide/Ca(2+) aqueous solutions with three different interaction modes of Ca(2+) with acetamide: tight contact, solvent-shared state, and separated interaction. The simulated results reveal that an EE could exhibit two different localization behaviors in these acetamide/Ca(2+) aqueous solutions depending on different amideCa(2+) interactions featuring different contact distances. For the tight contact and solvent-shared state of amideCa(2+) solutions, vertically injected diffuse EEs follow different mechanisms with different dynamics, forming a cavity-shaped hydrated electron or a hydrated amide anion, respectively. Meanwhile, for the separated state, only one localization pattern of a vertically injected diffuse EE towards the formation of hydrated amide anion is observed. The hindrance of hydrated Ca(2+) and the attraction of the hydrated amide group originating from its polarity and low energy π* orbital are the main driving forces. Additionally, different EE localization modes have different effects on the interaction between the amide group and Ca(2+) in turn. This work provides an important basis for further understanding the mechanisms and dynamics of localizations/transfers of radiation-produced EEs and associated EE-induced lesions and damage to biological species in real biological environments or other aqueous solutions.
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Affiliation(s)
- Ru Zhang
- Institute of Theoretical Chemistry, School of Chemistry and Chemical Engineering, Shandong University, 250100, P. R. China.
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10
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Shao P, Ding LP, Cai JT, Lu C, Liu B, Sun CB. Microhydration effects on the structures and electrophilic properties of cytidine. RSC Adv 2016. [DOI: 10.1039/c6ra11720a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Adiabatic electron affinities (AEAs) for cytidine hydrates with up to four water molecules.
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Affiliation(s)
- Peng Shao
- Department of Physics
- Shaanxi University of Science & Technology
- Xi'an 710021
- China
| | - Li-Ping Ding
- Department of Optoelectronic Science & Technology
- College of Electrical & Information Engineering
- Shaanxi University of Science & Technology
- Xi'an 710021
- China
| | - Jiang-Tao Cai
- Department of Physics
- Shaanxi University of Science & Technology
- Xi'an 710021
- China
| | - Cheng Lu
- Beijing Computational Science Research Center
- Beijing 100084
- China
| | - Bo Liu
- Department of Physics
- Shaanxi University of Science & Technology
- Xi'an 710021
- China
| | - Chang-Bo Sun
- Department of Physics
- Shaanxi University of Science & Technology
- Xi'an 710021
- China
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11
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Fogarasi G, Szalay PG. Quantum chemical MP2 results on some hydrates of cytosine: binding sites, energies and the first hydration shell. Phys Chem Chem Phys 2015; 17:29880-90. [PMID: 26487481 DOI: 10.1039/c5cp04563k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A detailed quantum chemical investigation was undertaken to obtain the structure and energetics of cytosine hydrates Cyt·nH2O, with n = 1 to 7. The MP2(fc)/aug-cc-pVDZ level was used as the standard, with some DFT (B3LYP) and coupled cluster calculations, as well as calculations with the aug-cc-pVTZ basis set added for comparison. In a systematic search for microhydrated forms of cytosine, we have found that several structures have not yet been reported in the literature. The energies of different isomers, as well as binding energies are compared. When predicting the stability of a complex, we suggest using a scheme where the water molecules are extracted from a finite model of bulk water. Finally, based on energetic data, we suggest a rational definition of the first hydration shell; with this definition, it contains just six water molecules.
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Affiliation(s)
- Géza Fogarasi
- Institute of Chemistry, Eötvös University, P.O. Box 32, H-1518 Budapest, Hungary.
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12
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Ho J, Yen H, Shi H, Cheng L, Weng C, Chou W, Chiu C, Cheng P. Microhydration Effects on the Ultrafast Photodynamics of Cytosine: Evidences for a Possible Hydration‐Site Dependence. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jr‐Wei Ho
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Hung‐Chien Yen
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Hui‐Qi Shi
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Li‐Hao Cheng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Chih‐Nan Weng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Wei‐Kuang Chou
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Chih‐Chung Chiu
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Po‐Yuan Cheng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
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13
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Ho J, Yen H, Shi H, Cheng L, Weng C, Chou W, Chiu C, Cheng P. Microhydration Effects on the Ultrafast Photodynamics of Cytosine: Evidences for a Possible Hydration‐Site Dependence. Angew Chem Int Ed Engl 2015; 54:14772-6. [DOI: 10.1002/anie.201507524] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/18/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Jr‐Wei Ho
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Hung‐Chien Yen
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Hui‐Qi Shi
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Li‐Hao Cheng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Chih‐Nan Weng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Wei‐Kuang Chou
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Chih‐Chung Chiu
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
| | - Po‐Yuan Cheng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30043 (R.O.C.)
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14
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González E, Lino J, Deriabina A, Herrera JNF, Poltev VI. Interactions of DNA bases with individual water molecules. Molecular mechanics and quantum mechanics computation results vs. experimental data. Biophysics (Nagoya-shi) 2014. [DOI: 10.1134/s0006350913050047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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15
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Gu B, Smyth M, Kohanoff J. Protection of DNA against low-energy electrons by amino acids: a first-principles molecular dynamics study. Phys Chem Chem Phys 2014; 16:24350-8. [DOI: 10.1039/c4cp03906h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The physical shielding and chemical stabilizing of the low energy electron by glycine around the thymine through proton transfer.
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Affiliation(s)
- Bin Gu
- Department of Physics
- Nanjing University of Information Science and Technology
- Nanjing 210044, China
- Atomistic Simulation Centre
- Queen's University Belfast
| | - Maeve Smyth
- Atomistic Simulation Centre
- Queen's University Belfast
- Belfast BT7 1NN, UK
| | - Jorge Kohanoff
- Atomistic Simulation Centre
- Queen's University Belfast
- Belfast BT7 1NN, UK
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16
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Shao P, Kuang XY, Ding LP, Zhao YR. Structures, electrophilic properties, and hydrogen bonds of cytidine, uridine, and their radical anions: Microhydration effects. J Chem Phys 2013; 139:024305. [PMID: 23862941 DOI: 10.1063/1.4812500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Structures, electrophilic properties, and hydrogen bonds of the neutral and anionic monohydrated nucleoside, (cytidine)H2O, and (uridine)H2O have been systematically investigated using density functional theory. Various water-binding sites were predicted by explicitly considering the optimized monohydrated structures. Meanwhile, predictions of electron affinities and vertical detachment energies were also carried out to investigate their electrophilic properties. By examining the singly occupied molecular orbital and natural population analysis, we found the excess negative charge is localized on the cytidine and uridine moiety in anionic monohydrates. This may be the reason why the strength of hydrogen bonding undergoes an obvious change upon the extra electron attachment. Based on the electron density (ρ) and reduced density gradient (RDG), we present an approach to map and analyze the weak interaction (especially hydrogen bond) in monohydrated cytidine and uridine. The scatter plots of RDG versus ρ allow us to identify the different type interactions. Meanwhile, the maps of the gradient isosurfaces show a rich visualization of hydrogen bond, van der Waals interaction, and steric effect.
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Affiliation(s)
- Peng Shao
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
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17
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Thicoipe S, Carbonniere P, Pouchan C. The Use of the GSAM Approach for the Structural Investigation of Low-Lying Isomers of Molecular Clusters from Density-Functional-Theory-Based Potential Energy Surfaces: The Structures of Microhydrated Nucleic Acid Bases. J Phys Chem A 2013; 117:7236-45. [DOI: 10.1021/jp401130a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sandrine Thicoipe
- Groupe de Chimie Théorique et Réactivité,
IPREM/ECP UMR CNRS 5254, Université de Pau et des Pays de l’Adour, F-64000 Pau, France
| | - Philippe Carbonniere
- Groupe de Chimie Théorique et Réactivité,
IPREM/ECP UMR CNRS 5254, Université de Pau et des Pays de l’Adour, F-64000 Pau, France
| | - Claude Pouchan
- Groupe de Chimie Théorique et Réactivité,
IPREM/ECP UMR CNRS 5254, Université de Pau et des Pays de l’Adour, F-64000 Pau, France
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18
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Neogi SG, Chaudhury P. Structure and spectroscopic aspects of water-halide ion clusters: A study based on a conjunction of stochastic and quantum chemical methods. J Comput Chem 2012; 34:471-91. [DOI: 10.1002/jcc.23156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/01/2012] [Accepted: 09/07/2012] [Indexed: 01/17/2023]
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19
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Gu J, Leszczynski J, Schaefer HF. Interactions of electrons with bare and hydrated biomolecules: from nucleic acid bases to DNA segments. Chem Rev 2012; 112:5603-40. [PMID: 22694487 DOI: 10.1021/cr3000219] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jiande Gu
- Drug Design & Discovery Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, CAS, PR China.
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20
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Gupta A, Jaeger HM, Compaan KR, Schaefer HF. Electron attachment to the guanine-cytosine nucleic acid base pair and the effects of monohydration and proton transfer. J Phys Chem B 2012; 116:5579-87. [PMID: 22530702 DOI: 10.1021/jp211608b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The guanine-cytosine (GC) radical anion and its interaction with a single water molecule is studied using ab initio and density functional methods. Z-averaged second-order perturbation theory (ZAPT2) was applied to GC radical anion for the first time. Predicted spin densities show that the radical character is localized on cytosine. The Watson-Crick monohydrated GC anion is compared to neutral GC·H2O, as well as to the proton-transferred analogue on the basis of structural and energetic properties. In all three systems, local minima are identified that correspond to water positioned in the major and minor grooves of macromolecular DNA. On the anionic surface, two novel structures have water positioned above or below the GC plane. On the neutral and anionic surfaces, the global minimum can be described as water interacting with the minor groove. These structures are predicted to have hydration energies of 9.7 and 11.8 kcal mol(-1), respectively. Upon interbase proton-transfer (PT), the anionic global minimum has water positioned in the major groove, and the hydration energy increases to 13.4 kcal mol(-1). PT GC·H2O(•-) has distonic character; the radical character resides on cytosine, while the negative charge is localized on guanine. The effects of proton transfer are further investigated through the computed adiabatic electron affinities (AEA) of GC and monohydrated GC, and the vertical detachment energies (VDE) of the corresponding anions. Monohydration increases the AEAs and VDEs by only 0.1 eV, while proton-transfer increases the VDEs substantially (0.8 eV). The molecular charge distribution of monohydrated guanine-cytosine radical anion depends heavily on interbase proton transfer.
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21
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Melicherčík M, Pašteka LF, Neogrády P, Urban M. Electron Affinities of Uracil: Microsolvation Effects and Polarizable Continuum Model. J Phys Chem A 2012; 116:2343-51. [DOI: 10.1021/jp211994k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Miroslav Melicherčík
- Department of Physical and Theoretical
Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
| | - Lukáš F. Pašteka
- Department of Physical and Theoretical
Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
| | - Pavel Neogrády
- Department of Physical and Theoretical
Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
| | - Miroslav Urban
- Department of Physical and Theoretical
Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
- Slovak University of Technology
in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917
24 Trnava, Slovakia
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22
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Gu J, Wang J, Leszczynski J. Electron Attachment to the Cytosine-Centered DNA Single Strands: Does Base Stacking Matter? J Phys Chem B 2012; 116:1458-66. [DOI: 10.1021/jp211386x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jiande Gu
- Drug Design & Discovery Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, CAS, Shanghai 201203, P. R. China
| | - Jing Wang
- Interdisciplinary Nanotoxicity
Center, Department of Chemistry, Jackson State University, Jackson,
Mississippi 39217, United States
| | - Jerzy Leszczynski
- Interdisciplinary Nanotoxicity
Center, Department of Chemistry, Jackson State University, Jackson,
Mississippi 39217, United States
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23
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Neogi SG, Chaudhury P. Structure and spectroscopy of water-fluoride microclusters: A combined genetic algorithm and DFT-based study. J Comput Chem 2011; 33:629-39. [DOI: 10.1002/jcc.21994] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 10/14/2011] [Accepted: 10/15/2011] [Indexed: 01/14/2023]
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24
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Ivanova B, Spiteller M. Conformation, optical properties, and absolute configuration of 2′,3′-isopropylideneadenosines: Theoretical vs. experimental study. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2011.08.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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25
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Smyth M, Kohanoff J. Excess electron localization in solvated DNA bases. PHYSICAL REVIEW LETTERS 2011; 106:238108. [PMID: 21770551 DOI: 10.1103/physrevlett.106.238108] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 05/02/2011] [Indexed: 05/31/2023]
Abstract
We present a first-principles molecular dynamics study of an excess electron in condensed phase models of solvated DNA bases. Calculations on increasingly large microsolvated clusters taken from liquid phase simulations show that adiabatic electron affinities increase systematically upon solvation, as for optimized gas-phase geometries. Dynamical simulations after vertical attachment indicate that the excess electron, which is initially found delocalized, localizes around the nucleobases within a 15 fs time scale. This transition requires small rearrangements in the geometry of the bases.
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Affiliation(s)
- Maeve Smyth
- Atomistic Simulation Centre, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
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26
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Pathak AK, Mukherjee T, Maity DK. Structure and IR Spectra of Microhydrated Cl2 with an Excess Electron: Experiment versus Theory. J Phys Chem A 2011; 115:3559-64. [DOI: 10.1021/jp112245v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. K. Pathak
- Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - T. Mukherjee
- Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - D. K. Maity
- Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400085, India
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27
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Dedíková P, Neogrády P, Urban M. Electron Affinities of Small Uracil−Water Complexes: A Comparison of Benchmark CCSD(T) Calculations with DFT. J Phys Chem A 2011; 115:2350-8. [DOI: 10.1021/jp111104j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Pavlína Dedíková
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
| | - Pavel Neogrády
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
| | - Miroslav Urban
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
- Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Slovak University of Technology in Bratislava, Bottova 25, SK-917 24 Trnava, Slovakia
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28
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Gu J, Wong NB, Xie Y, Schaefer FH. Electron attachment to a hydrated DNA duplex: the dinucleoside phosphate deoxyguanylyl-3',5'-deoxycytidine. Chemistry 2011; 16:13155-62. [PMID: 20922718 DOI: 10.1002/chem.201001306] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The minimal essential section of DNA helices, the dinucleoside phosphate deoxyguanylyl-3',5'-deoxycytidine dimer octahydrate, [dGpdC](2), has been constructed, fully optimized, and analyzed by using quantum chemical methods at the B3LYP/6-31+G(d,p) level of theory. Study of the electrons attached to [dGpdC](2) reveals that DNA double strands are capable of capturing low-energy electrons and forming electronically stable radical anions. The relatively large vertical electron affinity (VEA) predicted for [dGpdC](2) (0.38 eV) indicates that the cytosine bases are good electron captors in DNA double strands. The structure, charge distribution, and molecular orbital analysis for the fully optimized radical anion [dGpdC](2)(·-) suggest that the extra electron tends to be redistributed to one of the cytosine base moieties, in an electronically stable structure (with adiabatic electron affinity (AEA) 1.14 eV and vertical detachment energy (VDE) 2.20 eV). The structural features of the optimized radical anion [dGpdC](2)(·-) also suggest the probability of interstrand proton transfer. The interstrand proton transfer leads to a distonic radical anion [d(G-H)pdC:d(C+H)pdG](·-), which contains one deprotonated guanine anion and one protonated cytosine radical. This distonic radical anion is predicted to be more stable than [dGpdC](2)(·-). Therefore, experimental evidence for electron attachment to the DNA double helices should be related to [d(G-H)pdC:d(C+H)pdG](·-) complexes, for which the VDE might be as high as 2.7 eV (in dry conditions) to 3.3 eV (in fully hydrated conditions). Effects of the polarizable medium have been found to be important for increasing the electron capture ability of the dGpdC dimer. The ultimate AEA value for cytosine in DNA duplexes is predicted to be 2.03 eV in aqueous solution.
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Affiliation(s)
- Jiande Gu
- Drug Design & Discovery Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, CAS, Shanghai 201203, P. R. China.
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29
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Kim S, Schaefer HF. Vertical detachment energies of anionic thymidine: Microhydration effects. J Chem Phys 2010; 133:144305. [DOI: 10.1063/1.3488105] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Li X, Wang H, Bowen KH. Photoelectron spectroscopic study of the hydrated nucleoside anions: Uridine−(H2O)n=0–2, cytidine−(H2O)n=0–2, and thymidine−(H2O)n=0,1. J Chem Phys 2010; 133:144304. [DOI: 10.1063/1.3487735] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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31
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Glancy P, Beyermann WP. Dielectric properties of fully hydrated nucleotides in the terahertz frequency range. J Chem Phys 2010; 132:245102. [PMID: 20590216 DOI: 10.1063/1.3457941] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We use terahertz time domain spectroscopy (THz-TDS) to determine the complex frequency-dependent dielectric response of all four nucleotides at different dilute concentrations. In addition, the suspension model's ability to extract the dielectric response of just the nucleotide with the hydration shell epsilon(b) excluding the dielectric information relating to the bulk will be verified. The suspension model enables us to make the determination that the nucleotides have influences on the water molecules out to the fourth hydration shell. We use a two Debye relaxation fit model for water, all concentrations and all epsilon(b) values. We observed how the nucleotides affect the relaxation parameters in relation to that of pure bulk water. With this information, we notice a transition between purines and pyrimidines, where one is a hydrogen-bond network structure building type material with a low concentration increment and the other is a structure breaking type material with a low concentration decrement. Due to conductivity measurements, we determine that kinetic depolarization is a negligible affect compared to that of dielectric saturation, which we find to dominate where a decrement is found.
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Affiliation(s)
- P Glancy
- Department of Physics and Astronomy, University of California, Riverside, Riverside, California 92521, USA.
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32
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Ko YJ, Wang H, Radisic D, Stokes ST, Eustis SN, Bowen KH, Mazurkiewicz K, Storoniak P, Kowalczyk A, Haranczyk M, Gutowski M, Rak J. Barrier-free proton transfer induced by electron attachment to the complexes between 1‐methylcytosine and formic acid. Mol Phys 2010. [DOI: 10.1080/00268976.2010.515623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Yeon Jae Ko
- a Department of Chemistry , Johns Hopkins University , Baltimore , MD 21218 , USA
| | - Haopeng Wang
- a Department of Chemistry , Johns Hopkins University , Baltimore , MD 21218 , USA
| | - Dunja Radisic
- a Department of Chemistry , Johns Hopkins University , Baltimore , MD 21218 , USA
| | - Sarah T. Stokes
- a Department of Chemistry , Johns Hopkins University , Baltimore , MD 21218 , USA
| | - Soren N. Eustis
- a Department of Chemistry , Johns Hopkins University , Baltimore , MD 21218 , USA
| | - Kit H. Bowen
- a Department of Chemistry , Johns Hopkins University , Baltimore , MD 21218 , USA
| | - Kamil Mazurkiewicz
- b Department of Chemistry , University of Gdańsk , Sobieskiego 18 , 80-952 Gdańsk , Poland
| | - Piotr Storoniak
- b Department of Chemistry , University of Gdańsk , Sobieskiego 18 , 80-952 Gdańsk , Poland
| | - Arkadiusz Kowalczyk
- b Department of Chemistry , University of Gdańsk , Sobieskiego 18 , 80-952 Gdańsk , Poland
| | - Maciej Haranczyk
- c Computational Research Division, Lawrence Berkeley National Laboratory , Berkeley , CA 94720 , USA
| | - Maciej Gutowski
- d Chemistry-School of Engineering and Physical Sciencs, Heriot-Watt University , Edinburgh EH14 4AS , UK
| | - Janusz Rak
- b Department of Chemistry , University of Gdańsk , Sobieskiego 18 , 80-952 Gdańsk , Poland
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33
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Gu J, Xie Y, Schaefer HF. Electron attachment to hydrated oligonucleotide dimers: guanylyl-3',5'-cytidine and cytidylyl-3',5'-guanosine. Chemistry 2010; 16:5089-96. [PMID: 20349466 DOI: 10.1002/chem.200902977] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The dinucleoside phosphate deoxycytidylyl-3',5'-deoxyguanosine (dCpdG) and deoxyguanylyl-3',5'-deoxycytidine (dGpdC) systems are among the largest to be studied by reliable theoretical methods. Exploring electron attachment to these subunits of DNA single strands provides significant progress toward definitive predictions of the electron affinities of DNA single strands. The adiabatic electron affinities of the oligonucleotides are found to be sequence dependent. Deoxycytidine (dC) on the 5' end, dCpdG, has larger adiabatic electron affinity (AEA, 0.90 eV) than dC on the 3' end of the oligomer (dGpdC, 0.66 eV). The geometric features, molecular orbital analyses, and charge distribution studies for the radical anions of the cytidine-containing oligonucleotides demonstrate that the excess electron in these anionic systems is dominantly located on the cytosine nucleobase moiety. The pi-stacking interaction between nucleobases G and C seems unlikely to improve the electron-capturing ability of the oligonucleotide dimers. The influence of the neighboring base on the electron-capturing ability of cytosine should be attributed to the intensified proton accepting-donating interaction between the bases. The present investigation demonstrates that the vertical detachment energies (VDEs) of the radical anions of the oligonucleotides dGpdC and dCpdG are significantly larger than those of the corresponding nucleotides. Consequently, reactions with low activation barriers, such as those for O-C sigma bond and N-glycosidic bond breakage, might be expected for the radical anions of the guanosine-cytosine mixed oligonucleotides.
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Affiliation(s)
- Jiande Gu
- Drug Design & Discovery Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, CAS, Shanghai 201203, P. R. China.
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34
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Rasmussen AM, Lind MC, Kim S, Schaefer HF. Hydration of the Lowest Triplet States of the DNA/RNA Pyrimidines. J Chem Theory Comput 2010; 6:930-9. [DOI: 10.1021/ct900478c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andrew M. Rasmussen
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
| | - Maria C. Lind
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
| | - Sunghwan Kim
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602
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35
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Furmanchuk A, Isayev O, Shishkin OV, Gorb L, Leszczynski J. Hydration of nucleic acid bases: a Car–Parrinello molecular dynamics approach. Phys Chem Chem Phys 2010; 12:3363-75. [DOI: 10.1039/b923930h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Chen HY, Kao CL, Hsu SCN. Proton Transfer in Guanine−Cytosine Radical Anion Embedded in B-Form DNA. J Am Chem Soc 2009; 131:15930-8. [DOI: 10.1021/ja906899p] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hsing-Yin Chen
- Department of Medicinal and Applied Chemistry and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Chai-Lin Kao
- Department of Medicinal and Applied Chemistry and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Sodio C. N. Hsu
- Department of Medicinal and Applied Chemistry and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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37
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Gu J, Xie Y, Schaefer HF. Electron attachment to oligonucleotide dimers in water: Microsolvation-assisted base-stacking forms. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.03.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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38
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Bachrach SM, Nguyen TT, Demoin DW. Microsolvation of Cysteine: A Density Functional Theory Study. J Phys Chem A 2009; 113:6172-81. [PMID: 19408945 DOI: 10.1021/jp901491p] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Thuy T. Nguyen
- Department of Chemistry, Trinity University, San Antonio, Texas 78212
| | - Dustin W. Demoin
- Department of Chemistry, Trinity University, San Antonio, Texas 78212
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39
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Chen HY, Young PY, Hsu SCN. Theoretical evidence of barrier-free proton transfer in 7-azaindole-water cluster anions. J Chem Phys 2009; 130:165101. [DOI: 10.1063/1.3120604] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Duncan Lyngdoh RH, Schaefer HF. Elementary lesions in DNA subunits: electron, hydrogen atom, proton, and hydride transfers. Acc Chem Res 2009; 42:563-72. [PMID: 19231845 DOI: 10.1021/ar800077q] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
When DNA is damaged by ionizing radiation, the genes in a cell may acquire mutations or the cell could die. The smallest known DNA-damaging unit is an electron, often low-energy secondary electrons. Additional electrons and transfers involving hydrogen atoms, protons, and hydride anions can damage DNA subunits, including individual nucleobases and nucleoside pairs. Researchers would like to better understand the molecular mechanisms involved in DNA damage from ionizing radiation. In this Account, we highlight our theoretical investigations of the molecular mechanisms of DNA damage using quantum mechanical models. Our investigations use robust theoretical methods with computations conducted in the gas phase and with solution models. We calculate adiabatic electron affinities (AEAs), which describe the energetics of electronic attachment to closed-shell DNA subunits, for the free bases, nucleosides, nucleotides, base pairs, and single and double DNA strand units. Electron affinities for free nucleobases yield the order uracil > thymine > cytosine > guanine > adenine and the same order for the DNA nucleosides, mononucleotides, and nucleoside 3',5'-diphosphates. AEA values increase steadily with the size and complexity of the system because of greater hydration, glycosylation, nucleotide formation, and base pairing. We predict and experimental results partially confirm that most of the more complex and hydrated species are observable as radical anions. Our modeling studies indicate that depyrimidination reactions of radical anion nucleosides release cytosine more often than thymine. Recent experimental results support those findings. Our theoretical studies of DNA base-pair radical anions predict increases in electron affinity accompanying H bonding and solvation. Electron addition facilitates some proton transfers in these pairs, which results in strongly perturbed pairing configurations. Of all nucleobase moieties within the more complex radical anion systems, thymine is best able to retain a negative charge. Charge and spin are well-separated in some of these systems. Radical species derived via hydrogen abstraction from DNA subunits yield large AEA values because they form closed-shell anions. Our studies predict single-strand breaks following H abstraction from nucleotides. Some H-abstraction processes in the DNA base pairs lead to severe distortions in pairing configuration based on our calculations. This body of systematic theoretical studies provides realistic descriptions of some events that lead to elementary DNA lesions, while providing rationalizations for many observed phenomena. Such approaches can lead to the design of new experiments, which would contribute to our understanding of the chemical physics of nucleic acids.
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Affiliation(s)
| | - Henry F. Schaefer
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602
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41
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Pathak AK, Mukherjee T, Maity DK. Theoretical Study on the Spectroscopic Properties of CO3.−.nH2O Clusters: Extrapolation to Bulk. Chemphyschem 2008; 9:2259-64. [DOI: 10.1002/cphc.200800429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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42
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Yamagami R, Kobayashi K, Tagawa S. Formation of spectral intermediate G-C and A-T anion complex in duplex DNA studied by pulse radiolysis. J Am Chem Soc 2008; 130:14772-7. [PMID: 18841971 DOI: 10.1021/ja805127e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dynamics of electron adducts of 2'-deoxynucleotides and oligonucelotides (ODNs) were measured spectroscopically by nanosecond pulse radiolysis. The radical anions of the nucleotides were produced within 10 ns by the reaction of hydrated electrons (e(aq)(-)) and were protonated to form the corresponding neutral radicals. At pH 7.0, the radical anion of deoxythymidine (dT(*-)) was protonated to form the neutral radical dT(H)(*) in the time range of microseconds. The rate constant for the protonation was determined as 1.8 x 10(10) M(-1) s(-1). In contrast, the neutral radical of dC(H)(*) was formed immediately after the pulse, suggesting that the protonation occurs within 10 ns. The transient spectra of excess electrons of the double-stranded ODNs 5'-TAATTTAATAT-3' (AT) and 5'-CGGCCCGGCGC-3' (GC) differed from those of pyrimidine radicals (C and T) and their composite. In contrast, the spectra of the electron adducts of the single-stranded ODNs GC and AT exhibited characteristics of C and T, respectively. These results suggest that, in duplex ODNs, the spectral intermediates of G-C and A-T anions complex were formed. On the microsecond time scale, the subsequent changes in absorbance of the ODN AT had a first-order rate constant of 4 x 10(4) s(-1), reflecting the protonation of T.
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Affiliation(s)
- Ryuhei Yamagami
- The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki Osaka 567-0047, Japan
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43
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Kim S, Lind MC, Schaefer HF. Structures and Energetics of the Deprotonated Adenine−Uracil Base Pair, Including Proton-Transferred Systems. J Phys Chem B 2008; 112:3545-51. [DOI: 10.1021/jp711518n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sunghwan Kim
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602
| | - Maria C. Lind
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602
| | - Henry F. Schaefer
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602
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44
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Michaux C, Wouters J, Perpète EA, Jacquemin D. Microhydration of Protonated Glycine: An ab initio Family Tree. J Phys Chem B 2008; 112:2430-8. [DOI: 10.1021/jp710034r] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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45
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Radiation Effects On DNA: Theoretical Investigations Of Electron, Hole And Excitation Pathways To DNA Damage. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/978-1-4020-8184-2_20] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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46
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Kim S, Schaefer HF. Effects of Microsolvation on the Adenine−Uracil Base Pair and Its Radical Anion: Adenine−Uracil Mono- and Dihydrates. J Phys Chem A 2007; 111:10381-9. [PMID: 17705454 DOI: 10.1021/jp072727g] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microhydration effects upon the adenine-uracil (AU) base pair and its radical anion have been investigated by explicitly considering various structures of their mono- and dihydrates at the B3LYP/DZP++ level of theory. For the neutral AU base pair, 5 structures were found for the monohydrate and 14 structures for the dihydrate. In the lowest-energy structures of the neutral mono- and dihydrates, one and two water molecules bind to the AU base pair through a cyclic hydrogen bond via the N(9)-H and N(3) atoms of the adenine moiety, while the lowest-lying anionic mono- and dihydrates have a water molecule which is involved in noncyclic hydrogen bonding via the O4 atom of the uracil unit. Both the vertical detachment energy (VDE) and adiabatic electron affinity (AEA) of the AU base pair are predicted to increase upon hydration. While the VDE and AEA of the unhydrated AU pair are 0.96 and 0.40 eV, respectively, the corresponding predictions for the lowest-lying anionic dihydrates are 1.36 and 0.75 eV, respectively. Because uracil has a greater electron affinity than adenine, an excess electron attached to the AU base pair occupies the pi* orbital of the uracil moiety. When the uracil moiety participates in hydrogen bonding as a hydrogen bond acceptor (e.g., the N(6)-H(6a)...O(4) hydrogen bond between the adenine and uracil bases and the O(w)-H(w)...N and O(w)-H(w)...O hydrogen bonds between the AU pair and the water molecules), the transfer of the negative charge density from the uracil moiety to either the adenine or water molecules efficiently stabilizes the system. In addition, anionic structures which have C-H...O(w) contacts are energetically more favorable than those with N-H...O(w) hydrogen bonds, because the C-H...O(w) contacts do not allow the unfavorable electron density donation from the water to the uracil moiety. This delocalization effect makes the energetic ordering for the anionic hydrates very different from that for the corresponding neutrals.
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Affiliation(s)
- Sunghwan Kim
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602, USA
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