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Zhang Z, Mlýnský V, Krepl M, Šponer J, Stadlbauer P. Mechanical Stability and Unfolding Pathways of Parallel Tetrameric G-Quadruplexes Probed by Pulling Simulations. J Chem Inf Model 2024; 64:3896-3911. [PMID: 38630447 PMCID: PMC11094737 DOI: 10.1021/acs.jcim.4c00227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/02/2024] [Accepted: 04/02/2024] [Indexed: 05/14/2024]
Abstract
Guanine quadruplex (GQ) is a noncanonical nucleic acid structure formed by guanine-rich DNA and RNA sequences. Folding of GQs is a complex process, where several aspects remain elusive, despite being important for understanding structure formation and biological functions of GQs. Pulling experiments are a common tool for acquiring insights into the folding landscape of GQs. Herein, we applied a computational pulling strategy─steered molecular dynamics (SMD) simulations─in combination with standard molecular dynamics (MD) simulations to explore the unfolding landscapes of tetrameric parallel GQs. We identified anisotropic properties of elastic conformational changes, unfolding transitions, and GQ mechanical stabilities. Using a special set of structural parameters, we found that the vertical component of pulling force (perpendicular to the average G-quartet plane) plays a significant role in disrupting GQ structures and weakening their mechanical stabilities. We demonstrated that the magnitude of the vertical force component depends on the pulling anchor positions and the number of G-quartets. Typical unfolding transitions for tetrameric parallel GQs involve base unzipping, opening of the G-stem, strand slippage, and rotation to cross-like structures. The unzipping was detected as the first and dominant unfolding event, and it usually started at the 3'-end. Furthermore, results from both SMD and standard MD simulations indicate that partial spiral conformations serve as a transient ensemble during the (un)folding of GQs.
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Affiliation(s)
- Zhengyue Zhang
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
- CEITEC−Central
European Institute of Technology, Masaryk
University, Kamenice
5, Brno 625 00, Czech Republic
- National
Center for Biomolecular Research,
Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Miroslav Krepl
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Jiří Šponer
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Petr Stadlbauer
- Institute
of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
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Stadlbauer P, Mlýnský V, Krepl M, Šponer J. Complexity of Guanine Quadruplex Unfolding Pathways Revealed by Atomistic Pulling Simulations. J Chem Inf Model 2023; 63:4716-4731. [PMID: 37458574 PMCID: PMC10428220 DOI: 10.1021/acs.jcim.3c00171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Indexed: 08/15/2023]
Abstract
Guanine quadruplexes (GQs) are non-canonical nucleic acid structures involved in many biological processes. GQs formed in single-stranded regions often need to be unwound by cellular machinery, so their mechanochemical properties are important. Here, we performed steered molecular dynamics simulations of human telomeric GQs to study their unfolding. We examined four pulling regimes, including a very slow setup with pulling velocity and force load accessible to high-speed atomic force microscopy. We identified multiple factors affecting the unfolding mechanism, i.e.,: (i) the more the direction of force was perpendicular to the GQ channel axis (determined by GQ topology), the more the base unzipping mechanism happened, (ii) the more parallel the direction of force was, GQ opening and cross-like GQs were more likely to occur, (iii) strand slippage mechanism was possible for GQs with an all-anti pattern in a strand, and (iv) slower pulling velocity led to richer structural dynamics with sampling of more intermediates and partial refolding events. We also identified that a GQ may eventually unfold after a force drop under forces smaller than those that the GQ withstood before the drop. Finally, we found out that different unfolding intermediates could have very similar chain end-to-end distances, which reveals some limitations of structural interpretations of single-molecule spectroscopic data.
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Affiliation(s)
- Petr Stadlbauer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Miroslav Krepl
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech
Academy of Sciences, Královopolská 135, Brno 612 00, Czech Republic
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Bertini L, Libera V, Ripanti F, Seydel T, Paolantoni M, Orecchini A, Petrillo C, Comez L, Paciaroni A. Role of fast dynamics in the complexation of G-quadruplexes with small molecules. Phys Chem Chem Phys 2022; 24:29232-29240. [PMID: 36445842 DOI: 10.1039/d2cp03602a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
G-quadruplexes (G4s) formed by the human telomeric sequence AG3 (TTAG3)3 (Tel22) play a key role in cancer and aging. We combined elastic incoherent neutron scattering (EINS) and quasielastic incoherent neutron scattering (QENS) to characterize the internal dynamics of Tel22 G4s and to assess how it is affected by complexation with two standard ligands, Berberine and BRACO19. We show that the interaction with the two ligands induces an increase of the overall mobility of Tel22 as quantified by the mean squared displacements (MSD) of hydrogen atoms. At the same time, the complexes display a lower stiffness than G4 alone. Two different types of motion characterize the G4 nanosecond timescale dynamics. Upon complexation, an increasing fraction of G4 atomic groups participate in this fast dynamics, along with an increase in the relevant characteristic length scales. We suggest that the entropic contribution to the conformational free energy of these motions might be crucial for the complexation mechanisms.
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Affiliation(s)
- Luca Bertini
- Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy.
| | - Valeria Libera
- Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy. .,Istituto Officina dei Materiali-IOM, National Research Council-CNR, Via Alessandro Pascoli, 06123 Perugia, Italy.
| | - Francesca Ripanti
- Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy.
| | - Tilo Seydel
- Institut Max von Laue - Paul Langevin (ILL) 71 avenue des Martyrs, 38042 Grenoble, France
| | - Marco Paolantoni
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di Sotto, 6, 06123 Perugia, Italy
| | - Andrea Orecchini
- Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy.
| | - Caterina Petrillo
- Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy.
| | - Lucia Comez
- Istituto Officina dei Materiali-IOM, National Research Council-CNR, Via Alessandro Pascoli, 06123 Perugia, Italy.
| | - Alessandro Paciaroni
- Department of Physics and Geology, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy.
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Molecular dynamics simulations of G-quadruplexes: The basic principles and their application to folding and ligand binding. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2020. [DOI: 10.1016/bs.armc.2020.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Panczyk T, Wojton P, Wolski P. Mechanism of unfolding and relative stabilities of G-quadruplex and I-motif noncanonical DNA structures analyzed in biased molecular dynamics simulations. Biophys Chem 2019; 250:106173. [DOI: 10.1016/j.bpc.2019.106173] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/01/2022]
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Wolski P, Nieszporek K, Panczyk T. G-Quadruplex and I-Motif Structures within the Telomeric DNA Duplex. A Molecular Dynamics Analysis of Protonation States as Factors Affecting Their Stability. J Phys Chem B 2018; 123:468-479. [DOI: 10.1021/acs.jpcb.8b11547] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pawel Wolski
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30239 Cracow, Poland
| | - Krzysztof Nieszporek
- Department of Chemistry, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 3, 20031 Lublin, Poland
| | - Tomasz Panczyk
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30239 Cracow, Poland
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Bianchi F, Comez L, Biehl R, D’Amico F, Gessini A, Longo M, Masciovecchio C, Petrillo C, Radulescu A, Rossi B, Sacchetti F, Sebastiani F, Violini N, Paciaroni A. Structure of human telomere G-quadruplex in the presence of a model drug along the thermal unfolding pathway. Nucleic Acids Res 2018; 46:11927-11938. [PMID: 30407585 PMCID: PMC6294516 DOI: 10.1093/nar/gky1092] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/28/2018] [Accepted: 10/19/2018] [Indexed: 12/21/2022] Open
Abstract
A multi-technique approach, combining circular dichroism spectroscopy, ultraviolet resonance Raman spectroscopy and small angle scattering techniques, has been deployed to elucidate how the structural features of the human telomeric G-quadruplex d[A(GGGTTA)3GGG] (Tel22) change upon thermal unfolding. The system is studied both in the free form and when it is bound to Actinomycin D (ActD), an anticancer ligand with remarkable conformational flexibility. We find that at room temperature binding of Tel22 with ActD involves end-stacking upon the terminal G-tetrad. Structural evidence for drug-driven dimerization of a significant fraction of the G-quadruplexes is provided. When the temperature is raised, both free and bound Tel22 undergo melting through a multi-state process. We show that in the intermediate states of Tel22 the conformational equilibrium is shifted toward the (3+1) hybrid-type, while a parallel structure is promoted in the complex. The unfolded state of the free Tel22 is consistent with a self-avoiding random-coil conformation, whereas the high-temperature state of the complex is observed to assume a quite compact form. Such an unprecedented high-temperature arrangement is caused by the persistent interaction between Tel22 and ActD, which stabilizes compact conformations even in the presence of large thermal structural fluctuations.
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Affiliation(s)
- Federico Bianchi
- Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - Lucia Comez
- IOM-CNR c/o Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - Ralf Biehl
- JCNS & ICS, Forschungszentrum Jülich GmbH, Leo-Brandt Strasse, 52425 Jülich, Germany
| | - Francesco D’Amico
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Alessandro Gessini
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Marialucia Longo
- JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Juelich GmbH, Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Claudio Masciovecchio
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Caterina Petrillo
- Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - Aurel Radulescu
- JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Juelich GmbH, Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Barbara Rossi
- Elettra-Sincrotrone Trieste, Strada Statale 14 - km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Francesco Sacchetti
- Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia, Italy
| | - Federico Sebastiani
- Lehrstuhl für Physikalische Chemie 2, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Nicolò Violini
- JCNS, Forschungszentrum Jülich GmbH, Leo-Brandt Strasse, 52425 Jülich, Germany
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Pal S, Paul S. Conformational deviation of Thrombin binding G-quadruplex aptamer (TBA) in presence of divalent cation Sr 2+: A classical molecular dynamics simulation study. Int J Biol Macromol 2018; 121:350-363. [PMID: 30308284 DOI: 10.1016/j.ijbiomac.2018.09.102] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 08/27/2018] [Accepted: 09/17/2018] [Indexed: 11/28/2022]
Abstract
Thrombin binding TBA-G-quadruplex aptamer (TBA) plays a major role in blood coagulation cascade. The 15-mer TBA sequence tends to form four-stranded TBA-G-quadruplex structure. In this research work, a series of explicit solvent classical MD simulations of the TBA is carried out using different salt (SrCl2) concentrations (0, 50, 100 and 200 mM). Here we have also testified the effect of salt concentration of divalent cation Sr2+ on the conformational change of quadruplex DNA. The structural deviations, fluctuations, torsional angles and the affinity of the ion are explored at different salt concentrations. It is found that the conformation of TBA-G-quadruplex at 0 mM and 50 mM salt concentrations, is very much different than the other salt concentrations (100 mM and 200 mM). Also observed are as follows: (i) no exchange of Sr2+ ion between inside and outside of the channel, (ii) an enhancement in the Sr2+ ion density around the phosphate region of the loop residues as salt concentration increases and (iii) the stacking of T3 and T4 residues of loop-1 that appears up to 50 mM concentration, vanishes as the salt concentration is increased further.
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Affiliation(s)
- Saikat Pal
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India.
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