Ab initio study of the structural, tautomeric, pairing, and electronic properties of seleno-derivatives of thymine


Journal Article

The structural, tautomeric, hydrogen-bonding, stacking, and electronic properties of a seleno-derivative of thymine (T), denoted here as 4SeT and created by replacing 04 in T with Se, are investigated by means of ab initio computational techniques. The structural properties of T and 4SeT are very similar, and the geometrical differences are mainly limited to the adjacent environment of the C - Se bond. The canonical "keto" form is the most stable tautomer, in the gas phase and in aqueous solution, for both T and 4SeT. It is argued that the competition between two opposite trends, i.e., a decrease in the base-pairing ability and an increase of the stacking interaction upon incorporation of 4SeT into a duplex, likely explains the similar experimental melting points of a seleno-derivative duplex (Se-DNA) and its native counterpart. Interestingly, the underlying electronic structure shows that replacement of O4 with Se promotes a reduction in the HOMO-LUMO gap and an increase in interplane coupling, which suggests that Se-DNA could be potentially useful for nanodevice applications. This finding is further supported by the fact that transfer integrals between 4SeT ⋯ A stacked base pairs are larger than those determined for similarly stacked natural T ⋯ A pairs. © 2009 American Chemical Society.

Full Text

Duke Authors

Cited Authors

  • Vázquez-Mayagoitia, A; Huertas, O; Brancolini, G; Migliore, A; Sumpter, BG; Orozco, M; Javier Luque, F; Felice, RD; Fuentes-Cabrera, M

Published Date

  • October 29, 2009

Published In

Volume / Issue

  • 113 / 43

Start / End Page

  • 14465 - 14472

International Standard Serial Number (ISSN)

  • 1520-6106

Digital Object Identifier (DOI)

  • 10.1021/jp9057077

Citation Source

  • Scopus