School of Natural Sciences and Mathematics and Department of Materials Science, University of Texas at Dallas, Richardson, Texas 75080, USA.
J Phys Chem A. 2011 Oct 13;115(40):11045-9. doi: 10.1021/jp204894m. Epub 2011 Sep 19.
We employ a large scale molecular simulation based on bond-order ReaxFF to simulate the chemical reaction and study the damage to a large fragment of DNA molecule in the solution by ionizing radiation. We illustrate that the randomly distributed clusters of diatomic OH radicals that are primary products of megavoltage ionizing radiation in water-based systems are the main source of hydrogen abstraction as well as formation of carbonyl and hydroxyl groups in the sugar moiety that create holes in the sugar rings. These holes grow up slowly between DNA bases and DNA backbone, and the damage collectively propagates to a DNA single and double strand break.
我们采用基于键序 ReaxFF 的大规模分子模拟来模拟化学反应，并研究离子辐射对溶液中大片段 DNA 分子的损伤。我们的研究表明，水基体系中兆伏级离子辐射的初级产物——随机分布的双原子 OH 自由基簇是氢提取以及糖部分中羰基和羟基形成的主要来源，这些基团会在糖环中形成空洞。这些空洞在 DNA 碱基和 DNA 主链之间缓慢生长，损伤会逐渐扩展到 DNA 的单链和双链断裂。
