A TDDFT-based Study on the Proton-DNA Collision
| Autor: | Rodrigo Seraide, Gustavo Brunetto, Angel Rubio, Umberto De Giovannini, Mario A. Bernal |
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| Přispěvatelé: | Seraide R., Bernal M.A., Brunetto G., De Giovannini U., Rubio A. |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Models
Molecular Base pair First-principles FOS: Physical sciences 02 engineering and technology 010402 general chemistry 01 natural sciences Dissociation (chemistry) Settore FIS/03 - Fisica Della Materia chemistry.chemical_compound Fragmentation Physics - Chemical Physics Materials Chemistry Physics - Biological Physics Physical and Theoretical Chemistry Base Pairing Chemical Physics (physics.chem-ph) Chemistry Time-dependent density functional theory DNA 021001 nanoscience & nanotechnology Collision Phosphate Charged particle 0104 chemical sciences Surfaces Coatings and Films Energy Transfer Biological Physics (physics.bio-ph) Chemical physics Quantum Theory Density functional theory Protons Atomic physics 0210 nano-technology DNA Damage |
| Zdroj: | The Journal of Physical Chemistry B |
| Popis: | The interaction of heavy charged particles with DNA is of interest for several areas, from hadrontherapy to aero-space industry. In this paper, a TD-DFT study on the interaction of a 4 keV proton with an isolated DNA base pair was carried out. Ehrenfest dynamics was used to study the evolution of the system during and after the proton impact up to about 193 fs. This time was long enough to observe the dissociation of the target, which occurs between 80-100 fs. The effect of base pair linking to the DNA double helix was emulated by fixing the four O3' atoms responsible for the attachment. The base pair tends to dissociate into its main components, namely the phosphate groups, sugars and nitrogenous bases. A central impact with energy transfer of 17.9 eV only produces base damage while keeping the backbone intact. An impact on a phosphate group with energy transfer of about 60 eV leads to backbone break at that site together with base damage, while the opposite backbone site integrity is kept is this situation. As the whole system is perturbed during such a collision, no atom remains passive. These results suggest that base damage accompanies all backbone breaks since hydrogen bonds that keep bases together are much weaker that those between the other components of the DNA. |
| Databáze: | OpenAIRE |
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