Effect of oligomer length on vibrational coupling and energy relaxation in double-stranded DNA
Effect of oligomer length on vibrational coupling and energy relaxation in double-stranded DNA
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DOI：
10.1016/j.chemphys.2017.12.010
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发表时间：
2018-08-17
期刊：
影响因子：
2.3
通讯作者：
Hunt, Neil T.
中科院分区：
文献类型：
--
作者：
Hithell, Gordon;Donaldson, Paul M.;Hunt, Neil T.
利用二维红外光谱研究了A-Trich DNA低聚物长度对双链和单链结构的振动模式耦合和能量弛豫机制的影响。对于长到足以形成双DNA结构的低聚物，观察到DNA碱基的振动模式与主磷酸基团的对称拉伸振动的耦合。双相合金熔化时失去了耦合。低聚体长度和DNA二级结构对碱基模式振动弛豫的时间尺度和机制均无显著影响，这符合碱基模式到中间模式的级联过程，其中一些位于脱氧核糖基上，然后到达磷酸主链。研究表明，碱基和主链之间的振动耦合需要形成双螺旋结构，而振动能量管理是核苷酸的固有特性。(C) 2017 Elsevier B.V.版权所有
The effect of oligomer length on the vibrational mode coupling and energy relaxation mechanisms of A-Trich DNA oligomers in double-and single-stranded conformations has been investigated using two-dimensional infrared spectroscopy. Vibrational coupling of modes of the DNA bases to the symmetric stretching vibration of the backbone phosphate group was observed for oligomers long enough to form duplex-DNA structures. The coupling was lost upon melting of the duplex. No significant effect of oligomer length or DNA secondary structure was found on either the timescale for vibrational relaxation of the base modes or the mechanism, which was consistent with a cascade process from base modes to intermediate modes, some of which are located on the deoxyribose group, and subsequently to the phosphate backbone. The study shows that vibrational coupling between base and backbone requires formation of the double-helix structure while vibrational energy management is an inherent property of the nucleotide. (C) 2017 Elsevier B.V. All rights reserved.