Electron holes in G-Quadruplexes: The role of adenine ending groups
The study deals with four-stranded DNA structures (G-Quadruplexes), known to undergo ionization upon direct absorption of low-energy UV photons. Combining quantum chemistry calculations and time-resolved absorption spectroscopy with 266 nm excitation, it focuses on the electron holes generated in te...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/704468 |
| Acceso en línea: | http://hdl.handle.net/10486/704468 https://dx.doi.org/10.3390/ijms222413436 |
| Access Level: | acceso abierto |
| Palabra clave: | Adenine Cation Deoxyguanosine Phosphate Guanine Guanine Quadruplex Absorption Spectroscopy Anisotropy Deprotonation DNA Structure Electron Oxidative Stress Química |
| Sumario: | The study deals with four-stranded DNA structures (G-Quadruplexes), known to undergo ionization upon direct absorption of low-energy UV photons. Combining quantum chemistry calculations and time-resolved absorption spectroscopy with 266 nm excitation, it focuses on the electron holes generated in tetramolecular systems with adenine groups at the ends. Our computations show that the electron hole is placed in a single guanine site, whose location depends on the position of the adenines at the 3′ or 5′ ends. This position also affects significantly the electronic absorption spectrum of (G+ )• radical cations. Their decay is highly anisotropic, composed of a fast process (<2 µs), followed by a slower one occurring in ~20 µs. On the one hand, they undergo deprotonation to (G-H2)• radicals and, on the other, they give rise to a reaction product absorbing in the 300–500 nm spectral domain |
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