Open Access

ARTICLE

The Stability of Anionic States of Thymine-Glycine Dimers with Excess Electron

by Yugai Huang, , ,

1 School of Life Science, Chemistry and Chemical Engineering, Jiangsu Second Normal University, Nanjing, 210013, China.
2 Queen’s University, Belfast, Northern Ireland, Belfast BT7 1NN, United Kingdom.

* Corresponding Author: Huang Yugai. Email: .

Computers, Materials & Continua 2018, 57(3), 485-494. https://doi.org/10.32604/cmc.2018.03112

Abstract

It has been demonstrated that low energy electrons (LEEs) can induce serious DNA damages including bases loss and even single and double strand breaks. Experiments also showed that LEE induced DNA damages will be reduced with the presence of amino acids. For understanding of the protection of amino acids to DNA, the stability of 6 kinds of thymine and glycine (T-g) dimers with planar configurations with an excess electron were studied with density functional theory (DFT) method. The results show that, when the excess electron is vertically attached, all the dimers become more active with higher energy. After re-optimization, 4 kinds (66.7%) of T-g dimers become more stable than the corresponding neutral states. For the most stable anionic dimer noted as [34-A]-, the excess electron is localized on the thymine, while one proton transfers from glycine to thymine. The proton transformation decreases the activities and prevents further reactions of the excess electron. For other three dimers, there is no chemical topology change. The glycine attracts the excess electron with hydrogen-bonding to the thymine.

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