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Brovarets’ OO, Muradova A, Hovorun DM. Novel horizons of the conformationally-tautomeric transformations of the G·T base pairs: quantum-mechanical investigation. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2026510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ol’ha O. Brovarets’
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Alona Muradova
- Department of Molecular Biotechnology and Bioinformatics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Dmytro M. Hovorun
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
- Department of Molecular Biotechnology and Bioinformatics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
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Brovarets' OO, Muradova A, Hovorun DM. Novel mechanisms of the conformational transformations of the biologically important G·C nucleobase pairs in Watson–Crick, Hoogsteen and wobble configurations via the mutual rotations of the bases around the intermolecular H-bonds: a QM/QTAIM study. RSC Adv 2021; 11:25700-25730. [PMID: 35478902 PMCID: PMC9036977 DOI: 10.1039/d0ra08702e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 06/09/2021] [Indexed: 01/12/2023] Open
Abstract
It was established conformational transformations of the G·C nucleobase pairs, occurring via the mutual rotation of the G and C bases around the intermolecular H-bonds.
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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
- Kyiv
- Ukraine
| | - Alona Muradova
- Department of Molecular Biotechnology and Bioinformatics
- Institute of High Technologies
- Taras Shevchenko National University of Kyiv
- Kyiv
- Ukraine
| | - Dmytro M. Hovorun
- Department of Molecular and Quantum Biophysics
- Institute of Molecular Biology and Genetics
- National Academy of Sciences of Ukraine
- Kyiv
- Ukraine
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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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Brovarets’ OO, Hovorun DM. Key microstructural mechanisms of the 2-aminopurine mutagenicity: Results of extensive quantum-chemical research. J Biomol Struct Dyn 2019; 37:2716-2732. [DOI: 10.1080/07391102.2018.1495577] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Ol’ha O. Brovarets’
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
- Department of Molecular Biotechnology and Bioinformatics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, 2-h Akademika Hlushkova Ave, Kyiv, Ukraine
| | - Dmytro M. Hovorun
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
- Department of Molecular Biotechnology and Bioinformatics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, 2-h Akademika Hlushkova Ave, Kyiv, Ukraine
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Brovarets' OO, Tsiupa KS, Dinets A, Hovorun DM. Unexpected Routes of the Mutagenic Tautomerization of the T Nucleobase in the Classical A·T DNA Base Pairs: A QM/QTAIM Comprehensive View. Front Chem 2018; 6:532. [PMID: 30538979 PMCID: PMC6277528 DOI: 10.3389/fchem.2018.00532] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 10/12/2018] [Indexed: 01/24/2023] Open
Abstract
In this paper using quantum-mechanical (QM) calculations in combination with Bader's quantum theory of "Atoms in Molecules" (QTAIM) in the continuum with ε = 1, we have theoretically demonstrated for the first time that revealed recently highly-energetic conformers of the classical A·T DNA base pairs - Watson-Crick [A·T(wWC)], reverse Watson-Crick [A·T(wrWC)], Hoogsteen [A·T(wH)] and reverse Hoogsteen [A·T(wrH)] - act as intermediates of the intrapair mutagenic tautomerization of the T nucleobase owing to the novel tautomerisation pathways: A·T(wWC)↔A·T*(w⊥ WC); A·T(wrWC)↔A·T O 2 * (w⊥ rWC); A·T(wH)↔A·T*(w⊥ H); A·T(wrH)↔A·T O 2 * (w⊥ rH). All of them occur via the transition states as tight ion pairs (A+, protonated by the N6H2 amino group)·(T-, deprotonated by the N3H group) with quasi-orthogonal geometry, which are stabilized by the participation of the strong (A)N6+H···O4-/O2-(T) and (A)N6+H···N3-(T) H-bonds. Established tautomerizations proceed through a two-step mechanism of the protons moving in the opposite directions along the intermolecular H-bonds. Initially, proton moves from the N3H imino group of T to the N6H2 amino group of A and then subsequently from the protonated N6+H3 amino group of A to the O4/O2 oxygen atom of T, leading to the products - A·T*(w⊥ WC), A·T O 2 * (w⊥ rWC), A·T*(w⊥ H), and A·T O 2 * (w⊥ rH), which are substantially non-planar, conformationally-labile complexes. These mispairs are stabilized by the participation of the (A)N6H/N6H'···N3(T) and (T)O2H/O4H···N6(A) H-bonds, for which the pyramidalized amino group of A is their donor and acceptor. The Gibbs free energy of activation of these mutagenic tautomerizations lies in the range of 27.8-29.8 kcal·mol-1 at T = 298.15 K in the continuum with ε = 1.
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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, Kyiv, Ukraine
- Department of Pharmacology, Bogomolets National Medical University, Kyiv, Ukraine
| | - Kostiantyn S. Tsiupa
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Andrii Dinets
- Department of Surgery #4, Bogomolets National Medical University, Kyiv, Ukraine
| | - Dmytro M. Hovorun
- Department of Molecular and Quantum Biophysics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
- Department of Pathophysiology, Bogomolets National Medical University, Kyiv, Ukraine
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Synthesis, spectroscopic characterization and crystallographic behavior of ethyl 2-(4-methyl-(2-benzylidenehydrazinyl))thiazole-4-carboxylate: Experimental and theoretical (DFT) studies. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2018.04.083] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Non-dissociative structural transitions of the Watson-Crick and reverse Watson-Crick А·Т DNA base pairs into the Hoogsteen and reverse Hoogsteen forms. Sci Rep 2018; 8:10371. [PMID: 29991693 PMCID: PMC6039495 DOI: 10.1038/s41598-018-28636-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/21/2018] [Indexed: 11/08/2022] Open
Abstract
In this study it was theoretically shown that discovered by us recently (Brovarets' et al., Frontiers in Chemistry, 2018, 6:8; doi: 10.3389/fchem.2018.00008) high-energetical, significantly non-planar (symmetry C1), short-lived wobbled conformers of the classical Watson-Crick А·Т(WC), reverse Watson-Crick А·Т(rWC), Hoogsteen А·Т(Н) and reverse Hoogsteen А·Т(rН) DNA base pairs are the intermediates of their pairwise А∙Т(WC)/А∙Т(rWC) ↔ А∙Т(H)/А∙Т(rH) conformational transformations. These transitions do not require for their realization the energy-consumable anisotropic rotation of the amino group of A around the exocyclic C6-N6 bond. They are controlled by the non-planar transition states with quasi-orthogonal geometry (symmetry C1) joined by the single intermolecular (Т)N3H···N6(А) H-bond (~4 kcal∙mol-1). The Gibbs free energies of activation for these non-dissociative, dipole-active conformational transitions consist 7.33 and 7.81 kcal∙mol-1, accordingly. Quantum-mechanical (QM) calculations in combination with Bader's quantum theory of "Atoms in Molecules" (QTAIM) have been performed at the MP2/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of QM theory in the continuum with ε = 4 under normal conditions.
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Brovarets' OO, Voiteshenko IS, Hovorun DM. Physico-chemical profiles of the wobble ↔ Watson-Crick G*·2AP(w) ↔ G·2AP(WC) and A·2AP(w) ↔ A*·2AP(WC) tautomerisations: a QM/QTAIM comprehensive survey. Phys Chem Chem Phys 2018; 20:623-636. [PMID: 29227488 DOI: 10.1039/c7cp05139e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This study is intended to clarify in detail the tautomeric transformations of the wobble (w) G*·2AP(w) and A·2AP(w) nucleobase mispairs involving 2-aminopurine (2AP) into the Watson-Crick (WC) G·2AP(WC) and A*·2AP(WC) base mispairs (asterisks denote mutagenic tautomers of the DNA bases), respectively, by quantum-mechanical methods and Bader's Quantum Theory of Atoms in Molecules. Our previously reported methodology has been used, which allows the evolution of the physico-chemical parameters to be tracked along the entire internal reaction coordinate (IRC), not exclusively in the stationary states of these reactions. These biologically important G*·2AP(w) ↔ G·2AP(WC) and A·2AP(w) ↔ A*·2AP(WC) w ↔ WC tautomerisations, which are involved in mutagenic tautomerically-conformational pathways, determine the origin of the transitions and transversions induced by 2AP. In addition, it is established that they proceed through planar, highly stable, zwitterionic transition states and they exhibit similar physico-chemical profiles and stages of sequential intrapair proton transfer, followed by spatial rearrangement of the nucleobases relative to each other within the base pairs. These w ↔ WC tautomerisations occur non-dissociatively and are accompanied by a significant alteration in geometry (from wobble to Watson-Crick and vice versa) and redistribution of the specific intermolecular interactions, which can be divided into 10 patterns including AHB H-bonds and loosened A-H-B covalent bridges along the IRC of tautomerisation. Based on the redistribution of the geometrical and electron-topological parameters of the intrapair hydrogen bonds, exactly 9 key points have been allocated to characterize the evolution of these reactions.
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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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9
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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: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Brovarets' OO, Tsiupa KS, Hovorun DM. The A·T(rWC)/A·T(H)/A·T(rH) ↔ A·T*(rwWC)/A·T*(wH)/A·T*(rwH) mutagenic tautomerization via sequential proton transfer: a QM/QTAIM study. RSC Adv 2018; 8:13433-13445. [PMID: 35542561 PMCID: PMC9079753 DOI: 10.1039/c8ra01446a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 03/23/2018] [Indexed: 12/14/2022] Open
Abstract
In this study for the first time we have revealed by QM and QTAIM calculations at the MP2/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of QM theory the novel routes of the mutagenic tautomerization of three biologically important A·T DNA base pairs – reverse Watson–Crick A·T(rWC), Hoogsteen A·T(H) and reverse Hoogsteen A·T(rH) – followed by their rebuilding into the wobble (w) A·T*(rwWC), A·T*(wH) and A·T*(rwH) base mispairs by the participation of the mutagenic tautomers of the DNA bases (denoted by asterisk) and vice versa, thus complementing the physico-chemical property of the canonical A·T(WC) Watson–Crick DNA base pair reported earlier (Brovarets' et al., RSC Adv., 2015, 5, 99594–99605). These non-dissociative tautomeric transformations in the classical A·T(rWC), A·T(H) and A·T(rH) DNA base pairs proceed similarly to the canonical A·T(WC) DNA base pair via the intrapair sequential proton transfer with shifting towards major or minor grooves of DNA followed by further double proton transfer along the intermolecular H-bonds and are controlled by the plane symmetric and highly stable transition states – tight ion pairs formed by the A+ nucleobase, protonated by the N1/N7 nitrogen atoms, and T− nucleobase, deprotonated by the N3H imino group. Comparison of the estimated populations of the tautomerised states (10−21 to 10−14) with similar characteristics for the canonical A·T(WC) DNA base pair (10−8 to 10−7) leads authors to the conclusion, that only a base pair with WC architecture can be a building block of the DNA macromolecule as a genetic material, which is able for the evolutionary self-development. Among all four classical DNA base pairs, only A·T(WC) DNA base pair can ensure the proper rate of the spontaneous point errors of replication in DNA. We discovered tautomeric wobbling of the classical A·T DNA base pairs. This data evidence, that only a base pair with Watson–Crick architecture can be a building block of the DNA macromolecule as a genetic material, which is able for the evolutionary self-development.![]()
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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
- 03680 Kyiv
- Ukraine
| | - Kostiantyn S. Tsiupa
- Department of Molecular and Quantum Biophysics
- Institute of Molecular Biology and Genetics
- National Academy of Sciences of Ukraine
- 03680 Kyiv
- Ukraine
| | - Dmytro M. Hovorun
- Department of Molecular and Quantum Biophysics
- Institute of Molecular Biology and Genetics
- National Academy of Sciences of Ukraine
- 03680 Kyiv
- Ukraine
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Brovarets' OO, Voiteshenko IS, Pérez-Sánchez H, Hovorun DM. A QM/QTAIM detailed look at the Watson-Crick↔wobble tautomeric transformations of the 2-aminopurine·pyrimidine mispairs. J Biomol Struct Dyn 2017; 36:1649-1665. [PMID: 28514900 DOI: 10.1080/07391102.2017.1331864] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This work is devoted to the careful QM/QTAIM analysis of the evolution of the basic physico-chemical parameters along the intrinsic reaction coordinate (IRC) of the biologically important 2AP·T(WC)↔2AP·T*(w) and 2AP·C*(WC)↔2AP·C(w) Watson-Crick(WC)↔wobble(w) tautomeric transformations obtained at each point of the IRC using original authors' methodology. Established profiles reflect the high similarity between the courses of these processes. Basing on the scrupulous analysis of the profiles of their geometric and electron-topological parameters, it was established that the dipole-active WC↔w tautomerizations of the Watson-Crick-like 2AP·T(WC)/2AP·C*(WC) mispairs, stabilized by the two classical N3H⋯N1, N2H⋯O2 and one weak C6H⋯O4/N4 H-bonds, into the wobble 2AP·T*(w)/2AP·C(w) base pairs, respectively, joined by the two classical N2H⋯N3 and O4/N4H⋯N1 H-bonds, proceed via the concerted stepwise mechanism through the sequential intrapair proton transfer and subsequent large-scale shifting of the bases relative each other, through the planar, highly stable, zwitterionic transition states stabilized by the participation of the four H-bonds - N1+H⋯O4-/N4-, N1+H⋯N3-, N2+H⋯N3-, and N2+H⋯O2-. Moreover, it was found out that the 2AP·T(WC)↔2AP·T*(w)/2AP·C*(WC)↔2AP·C(w) tautomerization reactions occur non-dissociatively and are accompanied by the consequent replacement of the 10 unique patterns of the specific intermolecular interactions along the IRC. Obtained data are of paramount importance in view of their possible application for the control and management of the proton transfer, e.g. by external electric or laser fields.
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Affiliation(s)
- Ol'ha O Brovarets'
- a Department of Molecular and Quantum Biophysics , Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine , 150 Akademika Zabolotnoho Str., Kyiv 03680 , Ukraine.,b Department of Molecular Biotechnology and Bioinformatics , Institute of High Technologies, Taras Shevchenko National University of Kyiv , 2-h Akademika Hlushkova Ave., Kyiv 03022 , Ukraine
| | - Ivan S Voiteshenko
- b Department of Molecular Biotechnology and Bioinformatics , Institute of High Technologies, Taras Shevchenko National University of Kyiv , 2-h Akademika Hlushkova Ave., Kyiv 03022 , Ukraine
| | - Horacio Pérez-Sánchez
- c Computer Science Department , Bioinformatics and High Performance Computing (BIO-HPC) Research Group, Universidad Católica San Antonio de Murcia (UCAM) , Guadalupe, Murcia 30107 , Spain
| | - Dmytro M Hovorun
- a Department of Molecular and Quantum Biophysics , Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine , 150 Akademika Zabolotnoho Str., Kyiv 03680 , Ukraine.,b Department of Molecular Biotechnology and Bioinformatics , Institute of High Technologies, Taras Shevchenko National University of Kyiv , 2-h Akademika Hlushkova Ave., Kyiv 03022 , Ukraine
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Brovarets' OO, Hovorun DM. Proton tunneling in the A∙T Watson-Crick DNA base pair: myth or reality? J Biomol Struct Dyn 2015; 33:2716-20. [PMID: 26362836 DOI: 10.1080/07391102.2015.1092886] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The results and conclusions reached by Godbeer et al. in their recent work, that proton tunneling in the A∙T(WC) Watson-Crick (WC) DNA base pair occurs according to the Löwdin's (L) model, but with a small (~10(-9)) probability were critically analyzed. Here, it was shown that this finding overestimates the possibility of the proton tunneling at the A∙T(WC)↔A*∙T*(L) tautomerization, because this process cannot be implemented as a chemical reaction. Furthermore, it was outlined those biologically important nucleobase mispairs (A∙A*↔A*∙A, G∙G*↔G*∙G, T∙T*↔T*∙T, C∙C*↔C*∙C, H∙H*↔H*∙H (H - hypoxanthine)) - the players in the field of the spontaneous point mutagenesis - where the tunneling of protons is expected and for which the application of the model proposed by Godbeer et al. can be productive.
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Affiliation(s)
- Ol'ha O Brovarets'
- a 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.,b Department of Molecular Biotechnology and Bioinformatics , Institute of High Technologies, Taras Shevchenko National University of Kyiv , 2-h Akademika Hlushkova Ave., 03022 Kyiv , Ukraine
| | - Dmytro M Hovorun
- a 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.,b Department of Molecular Biotechnology and Bioinformatics , Institute of High Technologies, Taras Shevchenko National University of Kyiv , 2-h Akademika Hlushkova Ave., 03022 Kyiv , Ukraine
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Brovarets' OO, Hovorun DM. How does the long G·G* Watson-Crick DNA base mispair comprising keto and enol tautomers of the guanine tautomerise? The results of a QM/QTAIM investigation. Phys Chem Chem Phys 2015; 16:15886-99. [PMID: 24964351 DOI: 10.1039/c4cp01241k] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The double proton transfer (DPT) in the long G·G* Watson-Crick base mispair (|C6N1(G*)N1C6(G)| = 36.4°; C1 symmetry), involving keto and enol tautomers of the guanine (G) nucleobase, along two intermolecular neighboring O6H···O6 (8.39) and N1···HN1 (6.14 kcal mol(-1)) H-bonds that were established to be slightly anti-cooperative, leads to its transformation into the G*·G base mispair through a single transition state (|C6N1N1C6| = 37.1°; C1), namely to the interconversion into itself. It was shown that the G·G* ↔ G*·G tautomerisation via the DPT is assisted by the third specific contact, that sequentially switches along the intrinsic reaction coordinate (IRC) in an original way: (G)N2H···N2(G*) H-bond (-25.13 to -10.37) → N2···N2 van der Waals contact (-10.37 to -9.23) → (G)N2···HN2(G*) H-bond (-9.23 to 0.79) → (G*)N2···HN2(G) H-bond (0.79 to 7.35 Bohr). The DPT tautomerisation was found to proceed through the asynchronous concerted mechanism by employing the QM/QTAIM approach and the methodology of the scans of the geometric, electron-topological, energetic, polar and NBO properties along the IRC. Nine key points, that can be considered as part of the tautomerisation repertoire, have been established and analyzed in detail. Furthermore, it was shown that the G·G* or G*·G base mispair is a thermodynamically and dynamically stable structure with a lifetime of 8.22 × 10(-10) s and all 6 low-frequency intermolecular vibrations are able to develop during this time span. Lastly, our results highlight the importance of the G·G* ↔ G*·G DPT tautomerisation, which can have implications for biological and chemical sensing applications.
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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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Brovarets' OO, Hovorun DM. DPT tautomerisation of the G·A(syn) and A*·G*(syn) DNA mismatches: a QM/QTAIM combined atomistic investigation. Phys Chem Chem Phys 2015; 16:9074-85. [PMID: 24695821 DOI: 10.1039/c4cp00488d] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
By applying a combined QM and QTAIM atomistic computational approach we have established for the first time that the G·A(syn) and A*·G*(syn) DNA mismatches (rare tautomers are marked with an asterisk), causing spontaneous transversions with substantially various probabilities, radically differ from each other in their ability to tautomerise through the double proton transfer (DPT). The A*·G*(syn) mismatch tautomerises quite easily (ΔΔG(TS) ≈ 4·kT at room temperature) into the A·G*(syn) mismatch through the asynchronous concerted mechanism, whereas the G·A(syn) base mispair does not tautomerise via the DPT at all, since there is no local minimum corresponding to the tautomerised G*·A*(syn) mismatch on the potential energy surface. It was established that the A·G*(syn) base mispair is a dynamically unstable H-bonded complex with an extremely short lifetime of 2.17 × 10(-13) s. Consequently, the obtained results allow us to believe that spontaneous or forced dissociation of both the G·A(syn) and A*·G*(syn) DNA mismatches by the DNA-polymerase occurs with the preservation of the tautomeric status of the bases.
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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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Brovarets’ OO, Yurenko YP, Hovorun DM. The significant role of the intermolecular CH⋯O/N hydrogen bonds in governing the biologically important pairs of the DNA and RNA modified bases: a comprehensive theoretical investigation. J Biomol Struct Dyn 2014; 33:1624-52. [DOI: 10.1080/07391102.2014.968623] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Brovarets’ OO, Hovorun DM. Does the G·G*synDNA mismatch containing canonical and rare tautomers of the guanine tautomerise through the DPT? A QM/QTAIM microstructural study. Mol Phys 2014. [DOI: 10.1080/00268976.2014.927079] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Brovarets' OO, Hovorun DM. Atomistic nature of the DPT tautomerisation of the biologically important C·C* DNA base mispair containing amino and imino tautomers of cytosine: a QM and QTAIM approach. Phys Chem Chem Phys 2014; 15:20091-104. [PMID: 24154739 DOI: 10.1039/c3cp52644e] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A theoretical study of tautomerisation of the biologically important cytosine·cytosine* (C·C*) DNA mismatch with a propeller-like structure (|C4N3N3C4| = 32.4°; C1 symmetry) and cis-oriented N1H glycosidic bonds, formed by the amino and imino tautomers of the C nucleobase, via the asynchronous concerted double proton transfer (DPT) along two H-bonds through the transition state (TSC·C*↔C*·C) (|C4N3N3C4| = 48.5°; C1 symmetry) into the C*·C mispair was carried out for the first time. It was established that the C·C*/C*·C DNA base mispair is associated by the antiparallel N4H···N4 (6.66 kcal mol(-1)), N3H···N3 (6.47 kcal mol(-1)) H-bonds and the O2···O2 van der Waals (vdW) contact (0.33 kcal mol(-1)), while the zwitterionic TSC·C*↔C*·C is stabilized by the parallel N4(+)H···N4(-) (13.55 kcal mol(-1)), N3(+)H···N3(-) (13.20 kcal mol(-1)) H-bonds and the O2(+)···O2(-) vdW contact (0.60 kcal mol(-1)). It was shown that the C·C* ↔ C*·C tautomerisation via the DPT is assisted by the O2···O2 vdW contact, that in contrast to the two others N4H···N4 and N3H···N3 H-bonds exists along the entire intrinsic reaction coordinate (IRC) range. The positive values of the Grunenberg's compliance constants (30.919 and 21.384 Å mdyn(-1) for C·C*/C*·C and TSC·C*↔C*·C, respectively) indicate that the O2···O2 vdW contact is a stabilizing closed-shell interaction. It was found that the middle N3H···N3 H-bond is anti-cooperative with the upper N4H···N4 H-bond and cooperative with the lower O2···O2 vdW contact. The 9 key points, which can be considered as electron-topological "fingerprints" of the asynchronous concerted C·C* ↔ C*·C tautomerisation process via the DPT were revealed along the IRC and examined in detail. It was shown that the C·C*/C*·C base mispair is a thermodynamically and dynamically stable structure. Its lifetime is equal to 1.53 × 10(-7) s at the MP2/cc-pVQZ//B3LYP/6-311++G(d,p) level of theory in vacuum. All 6 low-frequency intermolecular vibrations are able to develop during this time span.
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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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Brovarets' OO, Zhurakivsky RO, Hovorun DM. DPT tautomerisation of the wobble guanine·thymine DNA base mispair is not mutagenic: QM and QTAIM arguments. J Biomol Struct Dyn 2014; 33:674-89. [PMID: 24650179 DOI: 10.1080/07391102.2014.897259] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We have shown for the first time, connecting QM methods with QTAIM analysis and using the methodology of the sweeps of the energetical, electron-topological and geometrical parameters, that the tautomerisation of the wobble guanine·thymine (wG·T) DNA base mispair into the wG(*)·T(*) base mispair induced by the double proton transfer (DPT), which undergoes a concerted asynchronous pathway, is not mutagenic. The wG·T → wG(*)·T(*) DPT tautomerisation does not result in the transition of the G base into its mutagenic tautomeric form G(*) able to mispair with the T base within the Watson-Crick base pairing scheme. This observation is explained by the so-called quantum protection of the wG·T DNA base mispair from its mutagenic tautomerisation - the dynamical non-stability of the tautomerised wG(*)·T(*) base mispair and significantly negative value of the Gibbs free energy of activation for the reverse reaction of the wG·T → wG(*)·T(*) DPT tautomerisation.
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Affiliation(s)
- Ol'ha O Brovarets'
- a 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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Brovarets’ OO, Zhurakivsky RO, Hovorun DM. A QM/QTAIM microstructural analysis of the tautomerisationviathe DPT of the hypoxanthine·adenine nucleobase pair. Mol Phys 2014. [DOI: 10.1080/00268976.2013.877170] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Brovarets' OO, Zhurakivsky RO, Hovorun DM. Does the tautomeric status of the adenine bases change upon the dissociation of the A*·Asyn Topal–Fresco DNA mismatch? A combined QM and QTAIM atomistic insight. Phys Chem Chem Phys 2014; 16:3715-25. [DOI: 10.1039/c3cp54708f] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Brovarets’ OO, Zhurakivsky RO, Hovorun DM. Structural, energetic and tautomeric properties of the T·T∗/T∗·T DNA mismatch involving mutagenic tautomer of thymine: A QM and QTAIM insight. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2013.12.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Brovarets' OO, Zhurakivsky RO, Hovorun DM. Is the DPT tautomerization of the long A·G Watson-Crick DNA base mispair a source of the adenine and guanine mutagenic tautomers? A QM and QTAIM response to the biologically important question. J Comput Chem 2013; 35:451-66. [PMID: 24382756 DOI: 10.1002/jcc.23515] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 11/12/2013] [Accepted: 11/30/2013] [Indexed: 02/04/2023]
Abstract
Herein, we first address the question posed in the title by establishing the tautomerization trajectory via the double proton transfer of the adenine·guanine (A·G) DNA base mispair formed by the canonical tautomers of the A and G bases into the A*·G* DNA base mispair, involving mutagenic tautomers, with the use of the quantum-mechanical calculations and quantum theory of atoms in molecules (QTAIM). It was detected that the A·G ↔ A*·G* tautomerization proceeds through the asynchronous concerted mechanism. It was revealed that the A·G base mispair is stabilized by the N6H···O6 (5.68) and N1H···N1 (6.51) hydrogen bonds (H-bonds) and the N2H···HC2 dihydrogen bond (DH-bond) (0.68 kcal·mol(-1) ), whereas the A*·G* base mispair-by the O6H···N6 (10.88), N1H···N1 (7.01) and C2H···N2 H-bonds (0.42 kcal·mol(-1) ). The N2H···HC2 DH-bond smoothly and without bifurcation transforms into the C2H···N2 H-bond at the IRC = -10.07 Bohr in the course of the A·G ↔ A*·G* tautomerization. Using the sweeps of the energies of the intermolecular H-bonds, it was observed that the N6H···O6 H-bond is anticooperative to the two others-N1H···N1 and N2H···HC2 in the A·G base mispair, while the latters are significantly cooperative, mutually strengthening each other. In opposite, all three O6H···N6, N1H···N1, and C2H···N2 H-bonds are cooperative in the A*·G* base mispair. All in all, we established the dynamical instability of the А*·G* base mispair with a short lifetime (4.83·10(-14) s), enabling it not to be deemed feasible source of the A* and G* mutagenic tautomers of the DNA bases. The small lifetime of the А*·G* base mispair is predetermined by the negative value of the Gibbs free energy for the A*·G* → A·G transition. Moreover, all of the six low-frequency intermolecular vibrations cannot develop during this lifetime that additionally confirms the aforementioned results. Thus, the A*·G* base mispair cannot be considered as a source of the mutagenic tautomers of the DNA bases, as the A·G base mispair dissociates during DNA replication exceptionally into the A and G monomers in the canonical tautomeric form.
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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 ; Research and Educational Center "State Key Laboratory of Molecular and Cell Biology", 150 Akademika Zabolotnoho Str., 03680, Kyiv, Ukraine; Department of Molecular Biology, Biotechnology and Biophysics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, 2-h Akademika Hlushkova Ave., 03022, Kyiv, Ukraine
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Brovarets' OO. [Under what conditions does G.C Watson-Crick DNA base pair acquire all four configurations characteristic for A.T Watson-Crick DNA base pair?]. UKRAINIAN BIOCHEMICAL JOURNAL 2013; 85:98-103. [PMID: 24319979 DOI: 10.15407/ubj85.04.098] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
At the MP2/6-311++G(2df,pd)//B3LYP/6-311++G(d,p) level of theory it was established for the first time, that the Löwdin's G*.C* DNA base pair formed by the mutagenic tautomers can acquire, as the A-T Watson-Crick DNA base pair, four biologically important configurations, namely: Watson-Crick, reverse Watson-Crick, Hoogsteen and reverse Hoogsteen. This fact demonstrates rather unexpected role of the tautomerisation of the one of the Watson-Crick DNA base pairs, in particular, via double proton transfer: exactly the G.C-->G*.C* tautomerisation allows to overcome steric hindrances for the implementation of the above mentioned configurations. Geometric, electron-topological and energetic properties of the H-bonds that stabilise the studied pairs, as well as the energetic characteristics of the latters are presented.
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Brovarets’ OO, Hovorun DM. The physicochemical essence of the purine·pyrimidine transition mismatches with Watson-Crick geometry in DNA: A·C*versaA*·C. A QM and QTAIM atomistic understanding. J Biomol Struct Dyn 2013; 33:28-55. [DOI: 10.1080/07391102.2013.852133] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Brovarets' OO, Hovorun DM. Atomistic understanding of the C·T mismatched DNA base pair tautomerization via the DPT: QM and QTAIM computational approaches. J Comput Chem 2013; 34:2577-90. [PMID: 23955922 DOI: 10.1002/jcc.23412] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 07/25/2013] [Indexed: 11/09/2022]
Abstract
It was established that the cytosine·thymine (C·T) mismatched DNA base pair with cis-oriented N1H glycosidic bonds has propeller-like structure (|N3C4C4N3| = 38.4°), which is stabilized by three specific intermolecular interactions-two antiparallel N4H…O4 (5.19 kcal mol(-1)) and N3H…N3 (6.33 kcal mol(-1)) H-bonds and a van der Waals (vdW) contact O2…O2 (0.32 kcal mol(-1)). The C·T base mispair is thermodynamically stable structure (ΔG(int) = -1.54 kcal mol(-1) ) and even slightly more stable than the A·T Watson-Crick DNA base pair (ΔG(int) = -1.43 kcal mol(-1)) at the room temperature. It was shown that the C·T ↔ C*·T* tautomerization via the double proton transfer (DPT) is assisted by the O2…O2 vdW contact along the entire range of the intrinsic reaction coordinate (IRC). The positive value of the Grunenberg's compliance constants (31.186, 30.265, and 22.166 Å/mdyn for the C·T, C*·T*, and TS(C·T ↔ C*·T*), respectively) proves that the O2…O2 vdW contact is a stabilizing interaction. Based on the sweeps of the H-bond energies, it was found that the N4H…O4/O4H…N4, and N3H…N3 H-bonds in the C·T and C*·T* base pairs are anticooperative and weaken each other, whereas the middle N3H…N3 H-bond and the O2…O2 vdW contact are cooperative and mutually reinforce each other. It was found that the tautomerization of the C·T base mispair through the DPT is concerted and asynchronous reaction that proceeds via the TS(C·T ↔ C*·T*) stabilized by the loosened N4-H-O4 covalent bridge, N3H…N3 H-bond (9.67 kcal mol(-1) ) and O2…O2 vdW contact (0.41 kcal mol(-1) ). The nine key points, describing the evolution of the C·T ↔ C*·T* tautomerization via the DPT, were detected and completely investigated along the IRC. The C*·T* mispair was revealed to be the dynamically unstable structure with a lifetime 2.13·× 10(-13) s. In this case, as for the A·T Watson-Crick DNA base pair, activates the mechanism of the quantum protection of the C·T DNA base mispair from its spontaneous mutagenic tautomerization through the DPT.
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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 Zabolotnoho Str., Kyiv, 03680, Ukraine; Research and Educational Center, State Key Laboratory of Molecular and Cell Biology, 150 Zabolotnoho Str., Kyiv, 03680, Ukraine; Department of Molecular Biotechnology and Bioinformatics, Institute of High Technologies, Taras Shevchenko National University of Kyiv, 2 Hlushkova Ave., Kyiv, 03022, Ukraine
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Brovarets’ OO, Hovorun DM. Why the tautomerization of the G·C Watson–Crick base pairviathe DPT does not cause point mutations during DNA replication? QM and QTAIM comprehensive analysis. J Biomol Struct Dyn 2013; 32:1474-99. [DOI: 10.1080/07391102.2013.822829] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Brovarets’ OO, Hovorun DM. Prototropic tautomerism and basic molecular principles of hypoxanthine mutagenicity: an exhaustive quantum-chemical analysis. J Biomol Struct Dyn 2013; 31:913-36. [PMID: 22962845 DOI: 10.1080/07391102.2012.715041] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Brovarets’ OO, Yurenko YP, Hovorun DM. Intermolecular CH···O/N H-bonds in the biologically important pairs of natural nucleobases: a thorough quantum-chemical study. J Biomol Struct Dyn 2013; 32:993-1022. [PMID: 23730732 DOI: 10.1080/07391102.2013.799439] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Brovarets’ OO, Zhurakivsky RO, Hovorun DM. DPT tautomerization of the long A∙A* Watson-Crick base pair formed by the amino and imino tautomers of adenine: combined QM and QTAIM investigation. J Mol Model 2013; 19:4223-37. [DOI: 10.1007/s00894-013-1880-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 05/02/2013] [Indexed: 12/01/2022]
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Brovarets OO, Hovorun DM. Can tautomerization of the A·T Watson–Crick base pairviadouble proton transfer provoke point mutations during DNA replication? A comprehensive QM and QTAIM analysis. J Biomol Struct Dyn 2013; 32:127-54. [DOI: 10.1080/07391102.2012.755795] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Brovarets' OO, Zhurakivsky RO, Hovorun DM. The physico-chemical "anatomy" of the tautomerization through the DPT of the biologically important pairs of hypoxanthine with DNA bases: QM and QTAIM perspectives. J Mol Model 2013; 19:4119-37. [PMID: 23292249 DOI: 10.1007/s00894-012-1720-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 12/03/2012] [Indexed: 10/27/2022]
Abstract
The biologically important tautomerization of the Hyp·Cyt, Hyp·Thy and Hyp·Hyp base pairs to the Hyp·Cyt, Hyp·Thy and Hyp·Hyp base pairs, respectively, by the double proton transfer (DPT) was comprehensively studied in vacuo and in the continuum with a low dielectric constant (ε = 4) corresponding to hydrophobic interfaces of protein-nucleic acid interactions by combining theoretical investigations at the B3LYP/6-311++G(d,p) level of QM theory with QTAIM topological analysis. Based on the sweeps of the energetic, electron-topological, geometric and polar parameters, which describe the course of the tautomerization along the intrinsic reaction coordinate (IRC), it was proved that the tautomerization through the DPT is concerted and asynchronous process for the Hyp·Cyt and Hyp·Thy base pairs, while concerted and synchronous for the Hyp·Hyp homodimer. The continuum with ε = 4 does not affect qualitatively the course of the tautomerization reaction for all studied complexes. The nine key points along the IRC of the Hyp·Cyt↔Hyp·Cyt and Hyp·Thy↔Hyp·Thy tautomerizations and the six key points of the Hyp·Hyp↔Hyp·Hyp tautomerization have been identified and fully characterized. These key points could be considered as electron-topological "fingerprints" of concerted asynchronous (for Hyp·Cyt and Hyp·Thy) or synchronous (for Hyp·Hyp) tautomerization process via the DPT. It was found, that in the Hyp·Cyt, Hyp·Thy, Hyp·Hyp and Hyp·Hyp base pairs all H-bonds are significantly cooperative and mutually reinforce each other, while the C2H…O2 H-bond in the Hyp·Cyt base pair and the O6H…O4 H-bond in the Hyp·Thy base pair behave anti-cooperatively, i.e., they become weakened, while two others become strengthened.
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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 Zabolotnoho Str, 03680, Kyiv, Ukraine
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Abdoli-Senejani M, Taherpour AA, Memarian HR, Khosravani M. Theoretical studies on the rotamers and dynamic behaviors of ethyl-5-acetyl-4-(3′,4′-dimethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3-carboxylate. Struct Chem 2012. [DOI: 10.1007/s11224-012-0037-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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