Communication: UV photoionization of cytosine catalyzed by Ag(+).
J Chem Phys
; 143(4): 041103, 2015 Jul 28.
Article
em En
| MEDLINE
| ID: mdl-26233098
The photo-induced damages of DNA in interaction with metal cations, which are found in various environments, still remain to be characterized. In this paper, we show how the complexation of a DNA base (cytosine (Cyt)) with a metal cation (Ag(+)) changes its electronic properties. By means of UV photofragment spectroscopy of cold ions, it was found that the photoexcitation of the CytAg(+) complex at low energy (315-282) nm efficiently leads to ionized cytosine (Cyt(+)) as the single product. This occurs through a charge transfer state in which an electron from the p orbital of Cyt is promoted to Ag(+), as confirmed by ab initio calculations at the TD-DFT/B3LYP and RI-ADC(2) theory level using the SV(P) basis set. The low ionization energy of Cyt in the presence of Ag(+) could have important implications as point mutation of DNA upon sunlight exposition.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prata
/
DNA
/
Citosina
/
Metais
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Estados Unidos