1
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Warman H, Slocombe L, Sacchi M. How proton transfer impacts hachimoji DNA. RSC Adv 2023; 13:13384-13396. [PMID: 37143915 PMCID: PMC10152326 DOI: 10.1039/d3ra00983a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/23/2023] [Indexed: 05/06/2023] Open
Abstract
Hachimoji DNA is a synthetic nucleic acid extension of DNA, formed by an additional four bases, Z, P, S, and B, that can encode information and sustain Darwinian evolution. In this paper, we aim to look into the properties of hachimoji DNA and investigate the probability of proton transfer between the bases, resulting in base mismatch under replication. First, we present a proton transfer mechanism for hachimoji DNA, analogous to the one presented by Löwdin years prior. Then, we use density functional theory to calculate proton transfer rates, tunnelling factors and the kinetic isotope effect in hachimoji DNA. We determined that the reaction barriers are sufficiently low that proton transfer is likely to occur even at biological temperatures. Furthermore, the rates of proton transfer of hachimoji DNA are much faster than in Watson-Crick DNA due to the barrier for Z-P and S-B being 30% lower than in G-C and A-T. Suggesting that proton transfer occurs more frequently in hachimoji DNA than canonical DNA, potentially leading to a higher mutation rate.
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Affiliation(s)
- Harry Warman
- School of Physics and Maths, University of Surrey Guildford GU2 7XH UK
| | - Louie Slocombe
- School of Chemistry and Chemical Engineering, University of Surrey Guildford GU2 7XH UK
| | - Marco Sacchi
- School of Chemistry and Chemical Engineering, University of Surrey Guildford GU2 7XH UK
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2
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From structure and dynamics to biomolecular functions: The ubiquitous role of solvent in biology. Curr Opin Struct Biol 2022; 77:102462. [PMID: 36150344 DOI: 10.1016/j.sbi.2022.102462] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 08/22/2022] [Indexed: 12/14/2022]
Abstract
Biological activity requires a solvent that can provide a suitable environment, which satisfies the twin need for stability and the ability to change. Among all the solvents water plays the most important role. We review, analyze, and comment on recent works on the structure and dynamics of water around biomolecules and their role in specific biological functions. While studies in the past have focused on understanding the biomolecule-water interactions through a hydration layer; recently the attention has shifted towards understanding functions at a molecular level. Such a microscopic understanding clearly requires elucidation of detailed dynamical processes where solvent molecules play an important role. Finally, we comment on the advances made in understanding the role of water inside a biological cell.
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3
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Gillet N, Bartocci A, Dumont E. Assessing the sequence dependence of pyrimidine-pyrimidone (6-4) photoproduct in a duplex double-stranded DNA: A pitfall for microsecond range simulation. J Chem Phys 2021; 154:135103. [PMID: 33832258 DOI: 10.1063/5.0041332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Sequence dependence of the (6-4) photoproduct conformational landscape when embedded in six 25-bp duplexes is evaluated along extensive unbiased and enhanced (replica exchange with solute tempering, REST2) molecular dynamics simulations. The structural reorganization as the central pyrimidines become covalently tethered is traced back in terms of non-covalent interactions, DNA bending, and extrusion of adenines of the opposite strands. The close sequence pattern impacts the conformational landscape around the lesion, inducing different upstream and downstream flexibilities. Moreover, REST2 simulations allow us to probe structures possibly important for damaged DNA recognition.
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Affiliation(s)
- Natacha Gillet
- Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5182, Laboratoire de Chimie, 46 allée d'Italie, F69364 Lyon, France
| | - Alessio Bartocci
- Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5182, Laboratoire de Chimie, 46 allée d'Italie, F69364 Lyon, France
| | - Elise Dumont
- Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5182, Laboratoire de Chimie, 46 allée d'Italie, F69364 Lyon, France
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4
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Tolosa S, Sansón J, Hidalgo A. A procedure to understanding the C-G to A-T transversion. SMD simulations from guanine oxidation pathways assisted by one H2O2 molecule in the C-G basis pair. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Tolosa S, Sansón J, Hidalgo A. Mechanisms of the T-A to C-G transition studied by SMD simulations: Deamination vs tautomerisation. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Raczyńska ED, Gal JF, Maria PC, Kamińska B, Igielska M, Kurpiewski J, Juras W. Purine tautomeric preferences and bond-length alternation in relation with protonation-deprotonation and alkali metal cationization. J Mol Model 2020; 26:93. [PMID: 32248379 PMCID: PMC7256107 DOI: 10.1007/s00894-020-4343-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 03/05/2020] [Indexed: 11/03/2022]
Abstract
Quantum chemical calculations were carried out for deprotonated (P-) and protonated purine (PH+) and for adducts with one alkali metal cation (P-M+ and PM+, where M+ is Li+ or Na+) in the gas phase {B3LYP/6-311+G(d,p)}, a model of perfectly apolar environment, and for selected structures in aqueous solution {PCM(water)//B3LYP/6-311+G(d,p)}, a reference polar medium for biological studies. All potential isomers of purine derivatives were considered, the favored structures indicated, and the preferred sites for protonation/deprotonation and cationization reactions determined. Proton and metal cation basicities of purine in the gas phase were discussed and compared with those of imidazole and pyrimidine. Bond-length alternations in the P, PH+, P-M+, and PM+ forms were quantitatively measured using the harmonic oscillator model of electron delocalization (HOMED) indices and compared with those for P. Variations of the HOMED values when proceeding from the purine structural building blocks, pyrimidine and imidazole, to the bicyclic purine system were also examined. Generally, the isolated NH isomers exhibit a strongly delocalized π-system (HOMED > 0.8). Deprotonation slightly increases the HOMED values, whereas protonation and cationization change the HOMED indices in different way. For bidentate M+-adducts, the HOMED values are larger than 0.9 like for the largely delocalized P-. The HOMED values correlate well in a comprehensive relationship with the relative Gibbs energies (ΔG) calculated for individual isomers whatever the purine form is, neutral, protonated, or cationized. When PCM-DFT model was utilized for P-, PH+, PM+, and P-M+ (M+ = Li+) both electron delocalization and relative stability are different from those for the molecules in vacuo. The solvation effects cause a slight increase in HOMEDs, whereas the ΔEs decrease, but in different ways. Hence, contribution of particular isomers in the isomeric mixtures of PH+, PM+, and P-M+ also varies. HOMED variations for the favored neutral, deprotonated, protonated, and lithiated forms of purine in the gas phase and aqueous solution.
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Affiliation(s)
- Ewa D Raczyńska
- Department of Chemistry, Warsaw University of Life Sciences (SGGW), 02-776, Warszawa, Poland.
| | - Jean-François Gal
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice, UMR 7272, 06108, Nice, France
| | - Pierre-Charles Maria
- Université Côte d'Azur, CNRS, Institut de Chimie de Nice, UMR 7272, 06108, Nice, France
| | - Beata Kamińska
- Department of Chemistry, Warsaw University of Life Sciences (SGGW), 02-776, Warszawa, Poland
| | - Małgorzata Igielska
- Department of Biotechnology, Warsaw University of Life Sciences (SGGW), 02-776, Warszawa, Poland
| | - Julian Kurpiewski
- Department of Biotechnology, Warsaw University of Life Sciences (SGGW), 02-776, Warszawa, Poland
| | - Weronika Juras
- Department of Biotechnology, Warsaw University of Life Sciences (SGGW), 02-776, Warszawa, Poland
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7
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Turaeva N, Oksengendler BL. Non-poissonian Distribution of Point Mutations in DNA. Front Chem 2020; 8:38. [PMID: 32083056 PMCID: PMC7005246 DOI: 10.3389/fchem.2020.00038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/13/2020] [Indexed: 12/01/2022] Open
Abstract
In general, for chemical reactions occurring in systems, where fluctuations are not negligibly small, it is necessary to introduce a master equation for distribution of probability of fluctuations. It has been established that the monomolecular reactions of a type as A ↔ X are described by the master equation, which leads to a Poisson distribution with the variance equal to the average value N 0. However, the consideration of the Löwdin mechanism as autocatalytic non-linear chemical reactions such as A + X ↔ 2X and the corresponding master equation lead to a non-Poissonian probability distribution of fluctuations. In the presented work, first-order autocatalysis has been applied to the Löwdin's mechanism of spontaneous mutations in DNA. Describing double proton transfers between complimentary nucleotide bases along the chain by first-order autocatalytic reactions, the corresponding master equation for protons in tautomeric states becomes non-linear, and at non-equilibrium conditions this leads to the non-Poissonian distribution of spontaneous mutations in DNA. It is also suggested that the accumulation of large fluctuations of successive cooperative concerted protons along the chain may produce higher non-linearities which could have a significant impact on some biochemical processes, occurring in DNA.
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Affiliation(s)
- Nigora Turaeva
- Department of Biological Sciences, Webster University, Saint Louis, MO, United States
| | - Boris L Oksengendler
- Arifov Institute of ion-plasma and Laser Technologies, Tashkent, Uzbekistan
- Ural Federal University, Yekaterinburg, Russia
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8
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Liu H, Cao J, Bian W. Double Proton Transfer in the Dimer of Formic Acid: An Efficient Quantum Mechanical Scheme. Front Chem 2019; 7:676. [PMID: 31750286 PMCID: PMC6842929 DOI: 10.3389/fchem.2019.00676] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 09/30/2019] [Indexed: 11/13/2022] Open
Abstract
Double proton transfer plays an important role in biology and chemistry, such as with DNA base pairs, proteins and molecular clusters, and direct information about these processes can be obtained from tunneling splittings. Carboxylic acid dimers are prototypes for multiple proton transfer, of which the formic acid dimer is the simplest one. Here, we present efficient quantum dynamics calculations of ground-state and fundamental excitation tunneling splittings in the formic acid dimer and its deuterium isotopologues. These are achieved with a multidimensional scheme developed by us, in which the saddle-point normal coordinates are chosen, the basis functions are customized for the proton transfer process, and the preconditioned inexact spectral transform method is used to solve the resultant eigenvalue problem. Our computational results are in excellent agreement with the most recent experiments (Zhang et al., 2017; Li et al., 2019).
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Affiliation(s)
- Hao Liu
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.,School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jianwei Cao
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Wensheng Bian
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.,School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, China
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9
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Soler-Polo D, Mendieta-Moreno JI, Trabada DG, Mendieta J, Ortega J. Proton Transfer in Guanine-Cytosine Base Pairs in B-DNA. J Chem Theory Comput 2019; 15:6984-6991. [DOI: 10.1021/acs.jctc.9b00757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Diego Soler-Polo
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Jesús I. Mendieta-Moreno
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Daniel G. Trabada
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Jesús Mendieta
- Departamento de Biotecnología, Universidad Francisco de Vitoria, E-28223 Pozuelo de Alarcón, Madrid, Spain
| | - José Ortega
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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10
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Tolosa S, Sansón JA, Hidalgo A. Theoretical Study of Adenine to Guanine Transition Assisted by Water and Formic Acid Using Steered Molecular Dynamic Simulations. Front Chem 2019; 7:414. [PMID: 31249828 PMCID: PMC6582222 DOI: 10.3389/fchem.2019.00414] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/20/2019] [Indexed: 01/22/2023] Open
Abstract
The free energy profile of the adenine to guanine transition in the gas and aqueous phases was obtained by applying steered molecular dynamic (SMD) simulations. Three processes were considered to explain the mechanism assisted by water and formic acid molecules. The first process is hydrolytic deamination of adenine, then oxidation of the hypoxanthine previously formed, and finally, the animation from xanthine to guanine. In the gas phase these processes indicate a slow and not spontaneous conversion (ΔG g = 4.07 kcal·mol-1, k = 5.59·10-40 s-1), and a lifetime for guanine of τ = 7.75·10+22 s. The presence of solvent makes the transition more difficult by increasing the reaction energy to 26.90 kcal·mol-1 and decreasing the speed of the process to 1.63·10-55 s-1. However, it decreases the energy of the deamination process to -9.63 kcal·mol-1 and the lifetime of guanine base to τ = 6.85·10+17 s when the surrounding medium used in the transition process is aqueous. The results show that the guanine could participate in genetic mutations based on the lifetimes obtained. Transition states and intermediates structures were analyzed at the molecular dynamic level. This allows to follow the mechanism over time and to calculate thermodynamic and kinetic properties.
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Affiliation(s)
- Santiago Tolosa
- Departamento de Ingeniería Química y Química Física, Universidad de Extremadura, Badajoz, Spain
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11
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Structural and thermodynamic studies of cytosine to thymine conversion in gas and solution phases using steered molecular dynamic simulations. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.12.152] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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i-Motif DNA structures upon electric field exposure: completing the map of induced genetic errors. Theor Chem Acc 2019. [DOI: 10.1007/s00214-019-2423-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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13
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Halim MA, Gheith OA, Makkeya Y, Nagib AM, Atta AF, Emam M, Yehia A, Said T, Nair P, Al-Otaibi T. Extended Efficacy of Low-Dose Valganciclovir for Prevention of Cytomegalovirus Disease in Intermediate-Risk Kidney Transplant Recipients: Two-Year Follow-Up. EXP CLIN TRANSPLANT 2019; 17:339-343. [PMID: 30674240 DOI: 10.6002/ect.2018.0020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES In a previous study, we evaluated 1-year outcomes of using low-dose valganciclovir prophylaxis for cytomegalovirus infection in intermediate-risk kidney transplant recipients. Whether this effect persists in the long term is unknown. We aimed to evaluate the 2-year follow up of such adopted prophylaxis. MATERIALS AND METHODS We randomized 2 matched groups of kidney transplant recipients (1:1) to receive valganciclovir as 450 mg daily (group 1) or 900 mg daily (group 2) for the first 6 months after kidney transplant. The final analysis included 196 patients as intermediate-risk patients (98 in each treatment group) after exclusion of 5 high-risk patients. Serologically, all patients were at moderate risk for cytomegalovirus infection. Long-term outcomes including cytomegalovirus disease, acute rejection, new-onset diabetes after transplant, graft loss, and patient survival were assessed. RESULTS Through year 2 of follow-up, cytomegalovirus infection was reported in only 1 patient in group 1 (at month 13) and 1 patient in group 2 (at month 19) (not significant). Biopsy-proven acute rejection episodes were not statistically different between the groups (2 episodes in group 1 and 6 in group 2; P = .431). New-onset diabetes posttransplant was reported in 8.1% in group 1 and 13.2% in group 2 (P = .535). Graft failure was equal in both groups (1 in each group) at 2 years of follow up (not significant). Patient survival was comparable in both groups (100% in group 1 versus 97.9% in group 2; P = .661). The total number of cytomegalovirus infections at 2 years was numerically less in group 1 (P = .128). CONCLUSIONS Low-dose valganciclovir prophylaxis for 6 months was associated with sustained reduction of cytomegalovirus infection up to 2 years after kidney transplant without significant impact on the acute rejection, new-onset diabetes posttransplant, or patient and graft outcomes.
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Affiliation(s)
- Medhat A Halim
- The Department of Medicine, Hamed Al-Essa Organ Transplantation Centre, Ibn Sina Hospital, Kuwait
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14
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Raczyńska ED, Makowski M. Effects of Positive and Negative Ionization on Prototropy in Pyrimidine Bases: An Unusual Case of Isocytosine. J Phys Chem A 2018; 122:7863-7879. [PMID: 30192141 DOI: 10.1021/acs.jpca.8b07539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intramolecular proton-transfers (prototropic conversions) have been studied for the guanine building block isocytosine (iC), and effects of positive ionization, called one-electron oxidation (iC - e → iC+•), and negative ionization, called one-electron reduction (iC + e → iC-•), on tautomeric conversions when proceeding from neutral to ionized isocytosine have been discussed. Although radical cations and radical anions are very short-lived species, the ionization effects could be investigated by quantum-chemical methods. Such kind of studies gives some information about the labile protons and the most basic positions in the neutral and radical forms of the tautomeric system. For investigations, the complete isomeric mixture of isocytosine has been considered and calculations performed in two extreme environments, apolar {DFT(B3LYP)/6-311+G(d,p)} and polar {PCM(water)//DFT(B3LYP)/6-311+G(d,p)}. For selected isomers, the G4 theory has also been applied. There are no good relations for energetic parameters of neutral and ionized forms. Ionization energies depend on localization of labile protons. Tautomeric equilibria for neutral and ionized isocytosine, favored sites of protonation and deprotonation, and favored structures of protonated and deprotonated forms strongly depend on environment. Acidity of iC+• is close to that of the iC conjugate acid, and basicity of iC-• is close to that of the iC conjugate base. This increase of acid-base properties of charged radicals explains the proton-transfer in ionized pairs of nucleobases. When compared to other pyrimidine bases such as uracil (U) and cytosine (C), which exhibit analogous tautomeric equilibria between nine prototropic tautomers as isocytosine, the tautomeric preferences for iC, iC+•, iC-•, U, U+•, U-•, C, C+•, and C-• are completely different. The differences suggest that acid-base properties of functional groups, their stabilities, and ionization energies play a principal role in proton-transfers for pyrimidine bases and influence compositions of tautomeric mixtures.
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Affiliation(s)
- Ewa D Raczyńska
- Department of Chemistry , Warsaw University of Life Sciences (SGGW) , ul. Nowoursynowska 159c , 02-776 Warszawa , Poland
| | - Mariusz Makowski
- Faculty of Chemistry , University of Gdańsk , ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
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15
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Arabi AA, Matta CF. Effects of Intense Electric Fields on the Double Proton Transfer in the Watson–Crick Guanine–Cytosine Base Pair. J Phys Chem B 2018; 122:8631-8641. [DOI: 10.1021/acs.jpcb.8b05053] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Alya A. Arabi
- College of Natural and Health Sciences, Zayed University, Abu Dhabi, P.O. Box 144534, United Arab Emirates
| | - Chérif F. Matta
- Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, Nova Scotia B3M 2J6, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4J3, Canada
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16
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Tolosa S, Sansón J, Hidalgo A. Theoretical study of mechanisms for double proton transfer in adenine–uracil base pair via steered molecular dynamic simulations. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.06.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Mechanisms for guanine–cytosine tautomeric equilibrium in solution via steered molecular dynamic simulations. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.12.091] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Arabi AA, Matta CF. Adenine–thymine tautomerization under the influence of strong homogeneous electric fields. Phys Chem Chem Phys 2018; 20:12406-12412. [DOI: 10.1039/c8cp01122b] [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
This paper reveals the key energy correction terms contributing to the low probability of AT tautomerization under electric fields.
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Affiliation(s)
- Alya A. Arabi
- College of Natural and Health Sciences
- Zayed University
- Abu Dhabi
- United Arab Emirates
| | - Chérif F. Matta
- Department of Chemistry and Physics
- Mount Saint Vincent University
- Halifax
- Canada
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19
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Tolosa S, Sansón JA, Hidalgo A. Theoretical study of mechanisms for the hydrolytic deamination of cytosine via steered molecular dynamic simulations. RSC Adv 2018; 8:34867-34876. [PMID: 35547048 PMCID: PMC9087476 DOI: 10.1039/c8ra07390b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 10/04/2018] [Indexed: 12/31/2022] Open
Abstract
Gibbs free energy profiles of the cytosine deamination assisted by a water molecule in a discrete aqueous medium were obtained by the application of Steered Molecular Dynamic (SMD) simulations. Two pathways were considered to explain the mechanism of this process, where the water molecule attacks the C–N bond to give an intermediate (an amino–hydroxy–oxo structure in the A-path, and a hydroxy–oxo in the B-path) as the determinant step of reaction. Stationary structures along both energy profiles were analyzed at molecular dynamics level, obtaining states with higher free energies than those from electronic calculations in the gas phase and in solution described as a continuous medium. From the results obtained, the more complex A-pathway, with five steps, was kinetically the most favorable (with an endergonic reaction energy of 7.41 kcal mol−1, a high barrier of 67.53 kcal mol−1, and a small velocity constant k2 = 1.80 × 10−37 s−1), concluding that the uracil base can participate in a spontaneous genetic mutation since the uracil–ammonia complex has a long lifetime of 6.10 × 1027 s. This process turns out exergonic and faster when carried out in gas phase simulation or electronic calculation with a continuous medium, due to the disappearance of explicit water molecules that can compete with the assistant molecule. Gibbs free energy profiles of the cytosine deamination assisted by a water molecule in a discrete aqueous medium were obtained by the application of Steered Molecular Dynamic (SMD) simulations.![]()
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Affiliation(s)
- S. Tolosa
- Departamento de Ingeniería Química y Química Física
- Universidad de Extremadura
- Badajoz
- Spain
| | - J. A. Sansón
- Departamento de Ingeniería Química y Química Física
- Universidad de Extremadura
- Badajoz
- Spain
| | - A. Hidalgo
- Departamento de Ingeniería Química y Química Física
- Universidad de Extremadura
- Badajoz
- Spain
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20
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Tolosa S, Sánchez J, Sansón J, Hidalgo A. Steered molecular dynamic simulations of the tautomeric equilibria in solution of DNA bases. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.03.118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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Roßbach S, Ochsenfeld C. Influence of Coupling and Embedding Schemes on QM Size Convergence in QM/MM Approaches for the Example of a Proton Transfer in DNA. J Chem Theory Comput 2017; 13:1102-1107. [PMID: 28195707 DOI: 10.1021/acs.jctc.6b00727] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The influence of embedding and coupling schemes on the convergence of the QM size in the QM/MM approach is investigated for the transfer of a proton in a DNA base pair. We find that the embedding scheme (mechanical or electrostatic) has a much greater impact on the convergence behavior than the coupling scheme (additive QM/MM or subtractive ONIOM). To achieve size convergence, QM regions with up to 6000 atoms are necessary for pure QM or mechanical embedding. In contrast, electrostatic embedding converges faster: for the example of the transfer of a proton between DNA base pairs, we recommend including at least five base pairs and 5 Å of solvent (including counterions) into the QM region, i.e., a total of 1150 atoms.
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Affiliation(s)
- Sven Roßbach
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU Munich) , Butenandtstr. 7, D-81377 Munich, Germany.,Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, University of Munich (LMU Munich) , Butenandtstr, 5-13, D-81377 Munich, Germany
| | - Christian Ochsenfeld
- Chair of Theoretical Chemistry, Department of Chemistry, University of Munich (LMU Munich) , Butenandtstr. 7, D-81377 Munich, Germany.,Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, University of Munich (LMU Munich) , Butenandtstr, 5-13, D-81377 Munich, Germany
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22
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Cerón-Carrasco JP, Jacquemin D. Exposing the G-quadruplex to electric fields: the role played by telomeres in the propagation of DNA errors. Phys Chem Chem Phys 2017; 19:9358-9365. [DOI: 10.1039/c7cp01034f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We use quantum calculations to assess the impact of external electric fields on the stability of G-quadruplex, a key structure in telomere functionality.
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Affiliation(s)
- José Pedro Cerón-Carrasco
- Bioinformatics and High Performance Computing Research Group (BIO-HPC)
- Universidad Católica San Antonio de Murcia (UCAM)
- Murcia
- Spain
| | - Denis Jacquemin
- CEISAM
- UMR CNRS 6230
- BP 92208
- Université de Nantes
- 44322 Nantes Cedex 3
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23
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Joseph S, Vakani B, Kundu R. Molecular phylogenetic study on few morphotypes of a patellogastropod Cellana karachiensis from northern Arabian Sea reveals unexpected genetic diversity. Mitochondrial DNA A DNA Mapp Seq Anal 2016; 29:181-191. [PMID: 28024423 DOI: 10.1080/24701394.2016.1261854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A group of limpets, Cellana karachiensis, exhibiting phenotypic plasticity were examined from Gujarat coastline India, using molecular phylogeny. Previous examination of the COI genes established the presence of three different haplotypes X, Y and Z, while present study showed three more haplotypes X1, X2 and Z1. Thus, a total of six COI gene haplotypes, having 99.23% to 99.85% sequence similarity, were observed with variations at six sites. Bayesian phylogenetic analysis shows divergence of lineages X-Y, X1-X2 and Z-Z1. Careful observation of nucleotide alterations showed a nonrandom mutation with more A↔G and C↔T transitions between closely related species of the genus Cellana. A stretch of 17 base pair, within COI region, was marked as region with high degree of variability between species of Cellana. Results suggest that this could be the beginning of speciation, with partial or complete reproductive barrier or these are already distinct species in different stages of evolution.
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Affiliation(s)
- Sneha Joseph
- a Department of Bioscience , Saurashtra University , Rajkot , Gujarat , India
| | - Bhavik Vakani
- a Department of Bioscience , Saurashtra University , Rajkot , Gujarat , India
| | - Rahul Kundu
- a Department of Bioscience , Saurashtra University , Rajkot , Gujarat , India
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24
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O'Brien JM, Beal MA, Yauk CL, Marchetti F. Next generation sequencing of benzo(a)pyrene-induced lacZ mutants identifies a germ cell-specific mutation spectrum. Sci Rep 2016; 6:36743. [PMID: 27829668 PMCID: PMC5103183 DOI: 10.1038/srep36743] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/14/2016] [Indexed: 12/19/2022] Open
Abstract
De novo mutations are implicated in a variety of genetic diseases and arise primarily in the male germline. We investigated whether male germ cells have unique mechanisms for spontaneous or chemically-induced mutation relative to somatic cells using the MutaMouse model. We recovered lacZ transgenes from sperm 42 days after a 28-day exposure to benzo(a)pyrene (BaP, 100 mg/kg/day) to assess mutations arising in dividing spermatogonia. BaP caused a 3.4-fold increase in lacZ mutant frequency over controls which increased to 4.1-fold after clonal correction. We then used next generation sequencing to compare the spontaneous and BaP-induced mutation spectra in sperm and bone marrow. The spontaneous spectrum in sperm had significantly more G:C to A:T transitions and fewer mutations at A:T basepairs than bone marrow. BaP predominantly induced G:C to T:A transversions in both cell types, and both were enriched for mutations at CpG dinucleotides. However, BaP induced significantly more deletions in sperm, but more G:C to A:T transitions and G:C to C:G transversions in bone marrow. Differences in error-prone translesion DNA synthesis polymerases may underlie the observed spectrum differences between sperm and bone marrow. These findings suggest that mutations in sperm can arise via mechanisms that are unique to male germ cells.
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Affiliation(s)
- Jason M O'Brien
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Marc A Beal
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, K1A 0K9, Canada
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25
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de Almeida M, Ourique G, Fulco U, Albuquerque E, de Moura F, Lyra M. Charge transport properties of a twisted DNA molecule: A renormalization approach. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2016.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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26
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Effects of ionization on stability of 1-methylcytosine - DFT and PCM studies. J Mol Model 2016; 22:146. [PMID: 27259531 PMCID: PMC4893064 DOI: 10.1007/s00894-016-3020-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/26/2016] [Indexed: 01/01/2023]
Abstract
Consequences of ionization were studied by quantum-chemical methods (DFT and PCM) for 1-methylcytosine (MC)—a model of the nucleobase cytosine (C) connected with sugar in DNA. For calculations, three prototropic tautomers (one amino and two imino forms) and two imino zwitterions were considered, including conformational or configurational isomerism of exo heterogroups. Ionization and interactions between neighboring groups affect intramolecular proton-transfers, geometric and thermodynamic parameters, and electron delocalization for individual isomers. We discovered that an imino isomer is present in the isomeric mixture in the highest amount for positively ionized MC. Its contribution in neutral and negatively ionized MC is considerably smaller. Acid-base parameters for selected radical ions were estimated in the gas phase and compared to those of neutral MC. Gas-phase acidity of radical cations is close to that of the conjugate acid of MC, and gas-phase basicity of radical anions is close to that of the conjugate base of MC. Various routes of amino-imino conversion between neutral and ionized isomers were considered. Energetic-barrier for intramolecular proton-transfer in MC is close to that in the parent system—formamidine.
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27
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Brovarets' OO, Hovorun DM. A novel conception for spontaneous transversions caused by homo-pyrimidine DNA mismatches: a QM/QTAIM highlight. Phys Chem Chem Phys 2016. [PMID: 26219928 DOI: 10.1039/c5cp03211c] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have firstly shown that the T·T(w) and C·C(w) DNA mismatches with wobble (w) geometry stay in slow tautomeric equilibrium with short T·T*(WC) and C·C*(WC) Watson-Crick (WC) mispairs. These non-dissociative tautomeric rearrangements are controlled by the plane-symmetric, highly stable, highly polar and zwitterionic transition states. The obtained results allow us to understand in what way the T·T(w) and C·C(w) mismatches acquire enzymatically competent T·T*(WC) and C·C*(WC) conformations directly in the hydrophobic recognition pocket of a high-fidelity DNA-polymerase, thereby producing thermodynamically non-equilibrium spontaneous transversions. The simplest numerical estimation of the frequency ratio of the TT to CC spontaneous transversions satisfactorily agrees with experimental data.
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Affiliation(s)
- Ol'ha O Brovarets'
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Akademika Zabolotnoho Str., 03680 Kyiv, Ukraine.
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By how many tautomerisation routes the Watson–Crick-like A·C* DNA base mispair is linked with the wobble mismatches? A QM/QTAIM vision from a biological point of view. Struct Chem 2015. [DOI: 10.1007/s11224-015-0687-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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