Modulation of psoralen DNA crosslinking kinetics associated with a triplex-forming oligonucleotide.
Modulation of psoralen DNA crosslinking kinetics associated with a triplex-forming oligonucleotide.
复制标题
与三链体形成寡核苷酸相关的补骨脂素 DNA 交联动力学的调节。
DOI：
10.1111/j.1751-1097.2007.00243.x
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发表时间：
2008
影响因子：
3.3
通讯作者：
Krishnan,Rajagopal
中科院分区：
文献类型：
--
作者：
Oh,DennisH;Suzara,Vincent;Krishnan,Rajagopal
一个三链形成的寡核苷酸(TFO)，HPRT3，连接到补骨脂素衍生物，被设计为靶向HPRT基因中的补骨脂素反应位点。HPRT3与合成的双链靶序列高亲和力结合。在相同的UVA辐射剂量下，补骨脂素单加合物(MA)与链间交联物(MA)的比例随TFO浓度的增加而降低，并随TFO浓度的增加而反转。当TFO浓度从10 nm增加到10 μm时，补骨脂素MA的形成效率相对不变，但链间交联的形成效率增加了数倍。缩短TFO以降低其解离常数或改变TFO结合位点两侧的DNA序列都不会改变MA和交联率的浓度依赖关系。与10 nmHPRT3相关的补骨脂素光动力学转化为与10 μmHPRT3相关的光动力学，并在10 μ毫秒加入不与HPRT3靶序列特异性相互作用的其他无关的TFOS。浓度为0.5%(VOL/VOL)或更高的甘油也能模拟高浓度的TFO促进交联剂的形成。这些结果表明，虽然补骨脂素可能被TFOS靶向于特定的序列反应，但与三链形成相关的光反应性也受到可能影响局部大分子环境的序列无关因素的调节。
A triplex‐forming oligonucleotide (TFO), HPRT3, conjugated to a psoralen derivative, was designed to target a psoralen reaction site within theHPRTgene. HPRT3 bound with high affinity to a synthetic duplex target sequence. At a uniform UVA radiation dose, the ratio of psoralen monoadducts (MA) to interstrand crosslinks decreased and inverted with increasing TFO concentration. As the TFO concentration increased from 10 nmto 10 μm, the efficiency of psoralen MA formation remained relatively constant but the efficiency of interstrand crosslink formation increased several‐fold. Neither shortening the TFO to reduce its dissociation constant nor altering the DNA sequences flanking the TFO binding site altered the concentration dependence of MA and crosslink yields. The psoralen photokinetics associated with 10 nmHPRT3 converted to those associated with 10 μmHPRT3 with the addition of other unrelated TFOs at 10 μmthat do not specifically interact with the HPRT3 target sequence. Glycerol at concentrations of 0.5% (vol/vol) or higher also mimicked high TFO concentrations in enhancing crosslink formation. These results demonstrate that while psoralen may be targeted to react at a particular sequence by TFOs, photoreactivity associated with triplex formation is also modulated by sequence‐independent factors that may affect the local macromolecular environment.