1
|
Palafox MA, Chalanchi SM, Isasi J, Premkumar R, Franklin Benial AM, Rastogi VK. Effect of bromine atom on the different tautomeric forms of microhydrated 5-bromouracil, in the DNA:RNA microhelix and in the interaction with human proteins. J Biomol Struct Dyn 2020; 38:5443-5463. [DOI: 10.1080/07391102.2019.1704878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- M. Alcolea Palafox
- Facultad de Ciencias Químicas, Departamento de Química-Fisica, Universidad Complutense de Madrid, Madrid, Spain
| | - S. M. Chalanchi
- Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran
| | - J. Isasi
- Facultad de Ciencias Químicas, Departamento de Química Inorgánica, Universidad Complutense de Madrid, Madrid, Spain
| | - R. Premkumar
- PG and Research Department of Physics, N.M.S.S.V.N. College, Madurai, Tamil Nadu, India
| | | | | |
Collapse
|
2
|
Alcolea Palafox M, Franklin Benial AM, K Rastogi V. Biomolecules of 2-Thiouracil, 4-Thiouracil and 2,4-Dithiouracil: A DFT Study of the Hydration, Molecular Docking and Effect in DNA:RNAMicrohelixes. Int J Mol Sci 2019; 20:E3477. [PMID: 31311161 PMCID: PMC6678171 DOI: 10.3390/ijms20143477] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/17/2022] Open
Abstract
The molecular structure of 2-thiouracil, 4-thiouracil and 2,4-dithiouracil was analyzed under the effect of the first and second hydration shell by using the B3LYP density functional (DFT) method, and the results were compared to those obtained for the uracil molecule. A slight difference in the water distribution appears in these molecules. On the hydration of these molecules several trends in bond lengths and atomic charges were established. The ring in uracil molecule appears easier to be deformed and adapted to different environments as compared to that when it is thio-substituted. Molecular docking calculations of 2-thiouracil against three different pathogens: Bacillus subtilis, Escherichia coli and Candida albicans were carried out. Docking calculations of 2,4-dithiouracil ligand with various targeted proteins were also performed. Different DNA: RNA hybrid microhelixes with uridine, 2-thiouridine, 4-thiouridine and 2,4-dithiouridine nucleosides were optimized in a simple model with three nucleotide base pairs. Two main types of microhelixes were analyzed in detail depending on the intramolecular H-bond of the 2'-OH group. The weaker Watson-Crick (WC) base pair formed with thio-substituted uracil than with unsubstituted ones slightly deforms the helical and backbone parameters, especially with 2,4-dithiouridine. However, the thio-substitution significantly increases the dipole moment of the A-type microhelixes, as well as the rise and propeller twist parameters.
Collapse
Affiliation(s)
- M Alcolea Palafox
- Departamento de Química-Física, Facultad de CienciasQuímicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | | | - V K Rastogi
- Indian Spectroscopy Society, KC 68/1, Old Kavinagar, Ghaziabad 201002, India
| |
Collapse
|
3
|
Alcolea Palafox M. Effect of the sulfur atom on S2 and S4 positions of the uracil ring in different DNA:RNA hybrid microhelixes with three nucleotide base pairs. Biopolymers 2019; 110:e23247. [PMID: 30676643 DOI: 10.1002/bip.23247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/03/2018] [Accepted: 11/07/2018] [Indexed: 02/06/2023]
Abstract
The effect of the sulphur atom on the uracil ring was analyzed in different DNA:RNA microhelixes with three nucleotide base-pairs, including uridine, 2-thiouridine, 4-thiouridine, 2,4-dithiouridine, cytidine, adenosine and guanosine. Distinct backbone and helical parameters were optimized at different density functional (DFT) levels. The Watson-Crick pair with 2-thiouridine appears weaker than with uridine, but its interaction with water molecules appears easier. Two types of microhelixes were found, depending on the H-bond of H2' hydroxyl atom: A-type appears with the ribose ring in 3 E-envelope C3' -endo, and B-type in 2 E-envelope C2' -endo. B-type is less common but it is more stable and with higher dipole-moment. The sulphur atoms significantly increase the dipole-moment of the microhelix, as well as the rise and propeller twist parameters. Simulations with four Na atoms H-bonded to the phosphate groups, and further hydration with explicit water molecules were carried out. A re-definition of the numerical value calculation of several base-pair and base-stacking parameters is suggested.
Collapse
Affiliation(s)
- Mauricio Alcolea Palafox
- Departamento de Química-Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
| |
Collapse
|
4
|
Alcolea Palafox M, Kattan D, Afseth N. FT-IR spectra of the anti-HIV nucleoside analogue d4T (Stavudine). Solid state simulation by DFT methods and scaling by different procedures. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.12.079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
5
|
Felske LR, Lenz SAP, Wetmore SD. Quantum Chemical Studies of the Structure and Stability of N-Methylated DNA Nucleobase Dimers: Insights into the Mutagenic Base Pairing of Damaged DNA. J Phys Chem A 2017; 122:410-419. [PMID: 29189004 DOI: 10.1021/acs.jpca.7b10485] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
DNA is constantly under attack from exogenous and endogenous sources that modify the chemical structure of the nucleobases. A common type of nucleobase damage is N-methylation, which can result in mutagenesis. Nevertheless, these lesions are often repaired by the DNA repair enzyme AlkB, albeit at varying rates. Herein we use density functional theory (B3LYP-D3(BJ)/6-311++G(2df,2p)//B3LYP/6-31G(d,p)) to comprehensively examine the structural and energetic properties of base pairs between seven nucleobase lesions resulting from N-methylation on the Watson-Crick (WC) binding face and each canonical nucleobase. By characterizing 105 stable nucleobase dimers, we provide fundamental details regarding the preferred lesion base pairings. Specifically, we reveal that the flexibility of the methylamino group resulting from methylation of an exocyclic amino substituent allows the 2MeG, 4MeC, and 6MeA lesions to maintain a preference for canonical WC base pairing, which correlates with the experimentally reported lack of mutagenicity for these damage products. In contrast, calculated distortions in key structural parameters and altered binding energies for base pairs involving adducts formed upon methylation of a ring nitrogen (namely, 1MeG, 3MeT, 1MeA, and 3MeC) help rationalize the associated mutagenicity and repair efficiencies. Most importantly, our work provides molecular-level information about the interactions between N-methylated and canonical nucleobases that is critical for future large-scale modeling of damaged DNA and enzyme-DNA complexes that strive to further uncover the mutagenicity and repair propensities of these detrimental lesions.
Collapse
Affiliation(s)
- Lindey R Felske
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge T1K 3M4, Alberta, Canada
| | - Stefan A P Lenz
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge T1K 3M4, Alberta, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge T1K 3M4, Alberta, Canada
| |
Collapse
|
6
|
Palafox MA. Structure and conformational analysis of the anti-HIV reverse transcriptase inhibitor AZT using MP2 and DFT methods. Differences with the natural nucleoside thymidine. Simulation of the 1st phosphorylation step with ATP. Phys Chem Chem Phys 2015; 16:24763-83. [PMID: 25317835 DOI: 10.1039/c4cp03695f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A comprehensive quantum-chemical investigation of the conformational landscape of the HIV-1 reverse transcriptase inhibitor AZT (3'-azido-3'-deoxythymidine) nucleoside analogue was carried out. The whole conformational parameters (χ, γ, β, δ, ϕ, P, νmax) were analysed as well as the NBO charges. The search located at least 55 stable structures, 9 of which were by MP2 within a 1 kcal mol(-1) electronic energy range of the global minimum. Most conformers were anti or high-anti around the glycoside bond and with North sugar ring puckering angles. The distribution of all the conformers according to the ranges of stability of the characteristic torsional angles was established. The results obtained were in accordance with those found in related anti-HIV nucleoside analogues. The best conformer in the anti form corresponded to the calculated values by MP2 of χ = -126.9°, β = 176.4° and γ = 49.1°. An analysis of the lowest vibrations in conformer C1 was carried out. The first hydration shell was simulated and the structural differences with the natural nucleoside deoxythymidine (dT) were determined. The first phosphorylation step was simulated by interacting ATP with the best hydrated clusters of AZT and dT. The Na cations act as a bridge between the phosphate moieties of ATP making it easy for -P3O3 to receive the H5' proton from AZT or dT. A proton-transfer mechanism is proposed through the water molecules. When the number of the water molecules surrounding AZT is lower than 8, the first phosphorylation step of AZT can be carried out. However, the appropriate orientation of the O5'-H in dT avoids this limitation and it can be performed with large numbers of water molecules.
Collapse
Affiliation(s)
- M Alcolea Palafox
- Chemical Physics Department, Chemistry Faculty, Complutense University, Ciudad Universitaria, Madrid-28040, Spain.
| |
Collapse
|
7
|
Ponikvar-Svet M, Zeiger DN, Liebman JF. Interplay of thermochemistry and structural chemistry, the journal (volume 25, 2014, issues 1–2) and the discipline. Struct Chem 2015. [DOI: 10.1007/s11224-015-0572-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
8
|
Alvarez-Ros MC, Palafox MA. Conformational analysis, molecular structure and solid state simulation of the antiviral drug acyclovir (zovirax) using density functional theory methods. Pharmaceuticals (Basel) 2014; 7:695-722. [PMID: 24915059 PMCID: PMC4078516 DOI: 10.3390/ph7060695] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 05/22/2014] [Accepted: 05/26/2014] [Indexed: 11/23/2022] Open
Abstract
The five tautomers of the drug acyclovir (ACV) were determined and optimised at the MP2 and B3LYP quantum chemical levels of theory. The stability of the tautomers was correlated with different parameters. On the most stable tautomer N1 was carried out a comprehensive conformational analysis, and the whole conformational parameters (R, β, Φ, φ1, φ2, φ3, φ4, φ5) were studied as well as the NBO Natural atomic charges. The calculations were carried out with full relaxation of all geometrical parameters. The search located at least 78 stable structures within 8.5 kcal/mol electronic energy range of the global minimum, and classified in two groups according to the positive or negative value of the torsional angle j1. In the nitrogen atoms and in the O2' and O5' oxygen atoms of the most stable conformer appear a higher reactivity than in the natural nucleoside deoxyguanosine. The solid state was simulated through a dimer and tetramer forms and the structural parameters were compared with the X-ray crystal data available. Several general conclusions were emphasized.
Collapse
Affiliation(s)
- Margarita Clara Alvarez-Ros
- Departamento de Química-Física I. Facultad de Ciencias Químicas, Universidad Complutense, Ciudad Universitaria, Madrid 28040, Spain.
| | - Mauricio Alcolea Palafox
- Departamento de Química-Física I. Facultad de Ciencias Químicas, Universidad Complutense, Ciudad Universitaria, Madrid 28040, Spain.
| |
Collapse
|
9
|
El-Sayed AA, Tamara Molina A, Álvarez-Ros M, Alcolea Palafox M. Conformational analysis of the anti-HIV Nikavir prodrug: comparisons with AZT and Thymidine, and establishment of structure–activity relationships/tendencies in other 6′-derivatives. J Biomol Struct Dyn 2014; 33:723-48. [DOI: 10.1080/07391102.2014.909743] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
| | - A. Tamara Molina
- Facultad de Ciencias Químicas, Departamento de Química-Física I, Universidad Complutense, Ciudad Universitaria, Madrid 28040, Spain
| | - M.C. Álvarez-Ros
- Facultad de Ciencias Químicas, Departamento de Química-Física I, Universidad Complutense, Ciudad Universitaria, Madrid 28040, Spain
| | - M. Alcolea Palafox
- Facultad de Ciencias Químicas, Departamento de Química-Física I, Universidad Complutense, Ciudad Universitaria, Madrid 28040, Spain
| |
Collapse
|
10
|
Alcolea Palafox M. Molecular structure differences between the antiviral Nucleoside Analogue 5-iodo-2′-deoxyuridine and the natural nucleoside 2′-deoxythymidine using MP2 and DFT methods: conformational analysis, crystal simulations, DNA pairs and possible behaviour. J Biomol Struct Dyn 2013; 32:831-51. [DOI: 10.1080/07391102.2013.789402] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|