FORMATION OF SINGLE AND DOUBLE STRAND BREAKS IN DNA ULTRAVIOLET IRRADIATED AT HIGH INTENSITY
FORMATION OF SINGLE AND DOUBLE STRAND BREAKS IN DNA ULTRAVIOLET IRRADIATED AT HIGH INTENSITY
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高强度紫外线照射 DNA 中单链和双链断裂的形成
DOI：
10.1111/j.1751-1097.1991.tb01991.x
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发表时间：
1991
影响因子：
3.3
通讯作者：
K. Minton
中科院分区：
文献类型：
--
作者：
T. Masnyk;K. Minton
DNA中由两个量子过程引起的单链断裂(SSB)是公认的。我们现在报道，双光子过程也会导致双链断裂(DSB)。用准分子激光(248 Nm)照射pUC19和M13噬菌体Rf DNA，激光强度分别为107、109、1010和1011W/m2，剂量高达30kJ/m2。凝胶电泳法测定DNA中超螺旋、开环、线形和短片段的比例。在通量上发现了线形分子，而超螺旋DNA仍然存在。在相对的链上相互靠近的独立SSB的随机出现(产生线性DNA)意味着在样品中每个分子都引入了许多SSB。如果是这样的话，不应该观察到没有SSB的超螺旋DNA。
The induction of single‐strand breaks (SSB) by two quantum processes in DNA is well established. We now report that biphotonic processes result in double‐strand breaks (DSB) as well. pUC19 and bacteriophage M13 RF DNA were irradiated using an excimer laser (248 nm) at intensities of 107, 109, 1010 and 1011 W/m2 and doses up to 30 kJ/m2. The proportion of DNA as supercoil, open circular, linear and short fragments was determined by gel electrophoresis. Linear molecules were noted at fluences where supercoiled DNA was still present. The random occurrence of independent SSB in proximity to each other on opposite strands (producing linear DNA) implies introduction of numerous SSB per molecule in the sample. If so, supercoiled DNA that has sustained no SSB should not be observed.