Department of Radiation Oncology, University of Texas, Southwestern Medical Center, Dallas, Texas 75390, USA.
J Comput Chem. 2010 Nov 15;31(14):2601-6. doi: 10.1002/jcc.21554.
Coherent control of OH-free radicals interacting with the spin-triplet state of a DNA molecule is investigated. A model Hamiltonian for molecular spin singlet-triplet resonance is developed. We illustrate that the spin-triplet state in DNA molecules can be efficiently populated, as the spin-injection rate can be tuned to be orders of magnitudes greater than the decay rate due to small spin-orbit coupling in organic molecules. Owing to the nano-second life-time of OH free radicals, a non-equilibrium free energy barrier induced by the injected spin triplet state that lasts approximately longer than one-micro second in room temperature can efficiently block the initial Hydrogen abstraction and DNA damage. For a direct demonstration of the spin-blockade effect, a molecular simulation based on an ab-initio Car-Parrinello molecular dynamics is deployed.
研究了与 DNA 分子的自旋三重态相互作用的 OH 自由基的相干控制。开发了用于分子自旋单重态-三重态共振的模型哈密顿量。我们说明，由于有机分子中的小自旋轨道耦合，自旋注入速率可以调整为比衰减速率大几个数量级，因此 DNA 分子中的自旋三重态可以有效地填充。由于 OH 自由基的纳秒寿命，由注入的自旋三重态引起的非平衡自由能势垒在室温下持续约超过 1 微秒的时间可以有效地阻止初始的氢提取和 DNA 损伤。为了直接证明自旋阻塞效应，部署了基于从头算 Car-Parrinello 分子动力学的分子模拟。
