1
|
Nandi S, Coane C, Villegas AE, Ray A, Di Felice R. The impact of G-quadruplex dynamics on inter-tetrad electronic couplings: a hybrid computational study. Phys Chem Chem Phys 2022; 24:22513-22522. [PMID: 36106845 DOI: 10.1039/d2cp03505g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The G-quadruplex is a fascinating nucleic acid motif with implications in biology, medicine, and nanotechnologies. G-quadruplexes can form in the telomeres at the edges of chromosomes and in other guanine-rich regions of the genome. They can also be engineered for exploitation as biological materials for nanodevices. Their higher stiffness and higher charge transfer rates make them better candidates in nanodevices than duplex DNA. For the development of molecular nanowires, it is important to optimize electron transport along the wire axis. One powerful basis to do so is by manipulating the structure, based on known effects that structural changes have on electron transport. Here, we investigate such effects, by a combination of classical simulations of the structure and dynamics and quantum calculations of electronic couplings. We find that this structure-function relationship is complex. A single helix shape parameter alone does not embody such complexity, but rather a combination of distances and angles between stacked bases influences charge transfer efficiency. By analyzing linear combinations of shape descriptors for different topologies, we identify the structural features that most affect charge transfer efficiency. We discuss the transferability of the proposed model and the limiting effects of inherent flexibility.
Collapse
Affiliation(s)
- Samprita Nandi
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA.
| | - Colin Coane
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA.
| | - Angel-Emilio Villegas
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA.
| | - Angana Ray
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA.
| | - Rosa Di Felice
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA. .,Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.,CNR Institute of Nanoscience, 41125 Modena, Italy
| |
Collapse
|
2
|
Mantela M, Morphis A, Lambropoulos K, Simserides C, Di Felice R. Effects of Structural Dynamics on Charge Carrier Transfer in B-DNA: A Combined MD and RT-TDDFT Study. J Phys Chem B 2021; 125:3986-4003. [PMID: 33857373 DOI: 10.1021/acs.jpcb.0c11489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hole transfer along the axis of duplex DNA has been the focus of physical chemistry research for decades, with implications in diverse fields, from nanotechnology to cell oxidative damage. Computational approaches are particularly amenable for this problem, to complement experimental data for interpretation of transfer mechanisms. To be predictive, computational results need to account for the inherent mobility of biological molecules during the time frame of experimental measurements. Here, we address the structural variability of B-DNA and its effects on hole transfer in a combined molecular dynamics (MD) and real-time time-dependent density functional theory (RT-TDDFT) study. Our results show that quantities that characterize the charge transfer process, such as the time-dependent dipole moment and hole population at a specific site, are sensitive to structural changes that occur on the nanosecond time scale. We extend the range of physical properties for which such a correlation has been observed, further establishing the fact that quantitative computational data on charge transfer properties should include statistical averages. Furthermore, we use the RT-TDDFT results to assess an efficient tight-binding method suitable for high-throughput predictions. We demonstrate that charge transfer, although affected by structural variability, on average, remains strong in AA and GG dimers.
Collapse
Affiliation(s)
- Marilena Mantela
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | - Andreas Morphis
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | - Konstantinos Lambropoulos
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | - Constantinos Simserides
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece
| | | |
Collapse
|
3
|
Llancalahuen FM, Fuentes JA, Carreño A, Zúñiga C, Páez-Hernández D, Gacitúa M, Polanco R, Preite MD, Arratia-Pérez R, Otero C. New Properties of a Bioinspired Pyridine Benzimidazole Compound as a Novel Differential Staining Agent for Endoplasmic Reticulum and Golgi Apparatus in Fluorescence Live Cell Imaging. Front Chem 2018; 6:345. [PMID: 30211148 PMCID: PMC6123694 DOI: 10.3389/fchem.2018.00345] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/23/2018] [Indexed: 12/16/2022] Open
Abstract
In this study, we explored new properties of the bioinspired pyridine benzimidazole compound B2 (2,4-di-tert-butyl-6-(3H-imidazo[4,5-c]pyridine-2-yl)phenol) regarding its potential use as a differential biomarker. For that, we performed 1D 1HNMR (TOCSY), UV-Vis absorption spectra in different organic solvents, voltammetry profile (including a scan-rate study), and TD-DFT calculations that including NBO analyses, to provide valuable information about B2 structure and luminescence. In our study, we found that the B2 structure is highly stable, where the presence of an intramolecular hydrogen bond (IHB) seems to have a crucial role in the stability of luminescence, and its emission can be assigned as fluorescence. In fact, we found that the relatively large Stokes Shift observed for B2 (around 175 nm) may be attributed to the stability of the B2 geometry and the strength of its IHB. On the other hand, we determined that B2 is biocompatible by cytotoxicity experiments in HeLa cells, an epithelial cell line. Furthermore, in cellular assays we found that B2 could be internalized by passive diffusion in absence of artificial permeabilization at short incubation times (15 min to 30 min). Fluorescence microscopy studies confirmed that B2 accumulates in the endoplasmic reticulum (ER) and Golgi apparatus, two organelles involved in the secretory pathway. Finally, we determined that B2 exhibited no noticeable blinking or bleaching after 1 h of continuous exposure. Thus, B2 provides a biocompatible, rapid, simple, and efficient way to fluorescently label particular organelles, producing similar results to that obtained with other well-established but more complex methods.
Collapse
Affiliation(s)
- Felipe M Llancalahuen
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
| | - Juan A Fuentes
- Laboratorio de Patogénesis y Genética Bacteriana, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Alexander Carreño
- Center of Applied Nanosciences, Universidad Andres Bello, Santiago, Chile.,Fondo Nacional de Ciencia y Tecnología (FONDECYT), Santiago, Chile
| | - César Zúñiga
- Center of Applied Nanosciences, Universidad Andres Bello, Santiago, Chile
| | | | | | - Rubén Polanco
- Centro de Biotecnología Vegeta, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Marcelo D Preite
- Departamento de Química Orgánica, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Carolina Otero
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
| |
Collapse
|
4
|
Zhou T, Yang L, Lu Y, Dror I, Dantas Machado AC, Ghane T, Di Felice R, Rohs R. DNAshape: a method for the high-throughput prediction of DNA structural features on a genomic scale. Nucleic Acids Res 2013; 41:W56-62. [PMID: 23703209 PMCID: PMC3692085 DOI: 10.1093/nar/gkt437] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a method and web server for predicting DNA structural features in a high-throughput (HT) manner for massive sequence data. This approach provides the framework for the integration of DNA sequence and shape analyses in genome-wide studies. The HT methodology uses a sliding-window approach to mine DNA structural information obtained from Monte Carlo simulations. It requires only nucleotide sequence as input and instantly predicts multiple structural features of DNA (minor groove width, roll, propeller twist and helix twist). The results of rigorous validations of the HT predictions based on DNA structures solved by X-ray crystallography and NMR spectroscopy, hydroxyl radical cleavage data, statistical analysis and cross-validation, and molecular dynamics simulations provide strong confidence in this approach. The DNAshape web server is freely available at http://rohslab.cmb.usc.edu/DNAshape/.
Collapse
Affiliation(s)
- Tianyin Zhou
- Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Hancock SP, Ghane T, Cascio D, Rohs R, Di Felice R, Johnson RC. Control of DNA minor groove width and Fis protein binding by the purine 2-amino group. Nucleic Acids Res 2013; 41:6750-60. [PMID: 23661683 PMCID: PMC3711457 DOI: 10.1093/nar/gkt357] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The width of the DNA minor groove varies with sequence and can be a major determinant of DNA shape recognition by proteins. For example, the minor groove within the center of the Fis–DNA complex narrows to about half the mean minor groove width of canonical B-form DNA to fit onto the protein surface. G/C base pairs within this segment, which is not contacted by the Fis protein, reduce binding affinities up to 2000-fold over A/T-rich sequences. We show here through multiple X-ray structures and binding properties of Fis–DNA complexes containing base analogs that the 2-amino group on guanine is the primary molecular determinant controlling minor groove widths. Molecular dynamics simulations of free-DNA targets with canonical and modified bases further demonstrate that sequence-dependent narrowing of minor groove widths is modulated almost entirely by the presence of purine 2-amino groups. We also provide evidence that protein-mediated phosphate neutralization facilitates minor groove compression and is particularly important for binding to non-optimally shaped DNA duplexes.
Collapse
Affiliation(s)
- Stephen P Hancock
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1737, USA
| | | | | | | | | | | |
Collapse
|