Jump to main content
Jump to site search

Issue 44, 2014
Previous Article Next Article

Protection of DNA against low-energy electrons by amino acids: a first-principles molecular dynamics study

Author affiliations

Abstract

Using first-principles molecular dynamics simulations, we have investigated the notion that amino acids can play a protective role when DNA is exposed to excess electrons produced by ionizing radiation. In this study we focus on the interaction of glycine with the DNA nucleobase thymine. We studied thymine–glycine dimers and a condensed phase model consisting of one thymine molecule solvated in amorphous glycine. Our results show that the amino acid acts as a protective agent for the nucleobase in two ways. If the excess electron is initially captured by the thymine, then a proton is transferred in a barrier-less way from a neighboring hydrogen-bonded glycine. This stabilizes the excess electron by reducing the net partial charge on the thymine. In the second mechanism the excess electron is captured by a glycine, which acts as a electron scavenger that prevents electron localization in DNA. Both these mechanisms introduce obstacles to further reactions of the excess electron within a DNA strand, e.g. by raising the free energy barrier associated with strand breaks.

Graphical abstract: Protection of DNA against low-energy electrons by amino acids: a first-principles molecular dynamics study

Back to tab navigation

Publication details

The article was received on 30 Aug 2014, accepted on 01 Oct 2014 and first published on 01 Oct 2014


Article type: Paper
DOI: 10.1039/C4CP03906H
Author version available: Download Author version (PDF)
Citation: Phys. Chem. Chem. Phys., 2014,16, 24350-24358
  •   Request permissions

    Protection of DNA against low-energy electrons by amino acids: a first-principles molecular dynamics study

    B. Gu, M. Smyth and J. Kohanoff, Phys. Chem. Chem. Phys., 2014, 16, 24350
    DOI: 10.1039/C4CP03906H

Search articles by author

Spotlight

Advertisements