Sequence dependence of energy transfer in DNA oligonucleotides.
Sequence dependence of energy transfer in DNA oligonucleotides.
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DOI：
10.1016/s0006-3495(00)76663-x
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发表时间：
2000-02
影响因子：
3.4
通讯作者：
Daguang Xu;T. Nordlund
中科院分区：
文献类型：
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作者：
Daguang Xu;T. Nordlund
用光学光谱法研究了合成的DNA寡聚体中从正常DNA碱基到2-氨基嘌呤碱基的单重态能量转移的顺序、温度、浓度和溶剂依赖性。在260- 280 nm处有一个可变的荧光激发带，直接显示了转移。腺嘌呤（A）是一个数量级的最有效的能量供体。与2AP相邻的A堆充当2AP激励的天线。A和2AP之间插入的G、C或T碱基有效地阻断了从A到2AP的转移。碱基堆积促进了能量转移，而碱基配对则略微降低了能量转移。效率在单链和双链寡聚体中具有不同的温度依赖性，并且在所测量的样品中在0°C以下最高。效率转变远低于双链十聚体的解链转变。双链十聚体d（CTGA[2AP]TTCAG）2中的转移效率适度依赖于样品和盐浓度，并且具有溶剂依赖性。除了沿着沿着的A，在生理温度下转移超过几个碱基是不可能的，这表明单线态能量转移不是DNA中UV损伤定位的主要因素。这些结果与最近观察到的电子转移从2AP到G的寡核苷酸的共同特点。
The sequence, temperature, concentration, and solvent dependence of singlet energy transfer from normal DNA bases to the 2-aminopurine base in synthesized DNA oligomers were investigated by optical spectroscopy. Transfer was shown directly by a variable fluorescence excitation band at 260–280nm. Adenine (A) is the most efficient energy donor by an order of magnitude. Stacks of A adjacent to 2AP act as an antenna for 2AP excitation. An interposed G, C, or T base between A and 2AP effectively blocks transfer from A to 2AP. Base stacking facilitates transfer, while base pairing reduces energy transfer slightly. The efficiency is differentially temperature dependent in single- and double-stranded oligomers and is highest below 0°C in samples measured. An efficiency transition occurs well below the melting transition of a double-stranded decamer. The transfer efficiency in the duplex decamer d(CTGA[2AP]TTCAG)2is moderately dependent on the sample and salt concentration and is solvent dependent. Transfer at physiological temperature over more than a few bases is improbable, except along consecutive A's, indicating that singlet energy transfer is not a major factor in the localization of UV damage in DNA. These results have features in common with recently observed electron transfer from 2AP to G in oligonucleotides.