Formation of purine photoproducts in a defined human DNA sequence.
Formation of purine photoproducts in a defined human DNA sequence.
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在确定的人类 DNA 序列中形成嘌呤光产物。
DOI：
10.1111/j.1751-1097.1989.tb08430.x
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发表时间：
1989
影响因子：
3.3
通讯作者：
Duker,NJ
中科院分区：
文献类型：
--
作者：
Gallagher,PE;Duker,NJ
用一段确定的人DNA序列研究了宽谱紫外线照射（250-400 nm）对DNA碱基损伤的形成。将经过照射的92个碱基对的人Alphoid片段的3端与从噬菌体T4感染的E中纯化的酶部分一起孵育。如先前所报道的，通过测序凝胶对反应产物的分析显示含嘌呤的光产物以及嘧啶环丁烷光二聚体的酶切。嘌呤切割活性不需要金属离子，并且不受β-巯基乙醇或二硫苏糖醇的影响。嘌呤光产物的形成与缓冲液无关;这些损伤是通过在Tris、Hepes或磷酸盐缓冲液中照射DNA产生的。它们在260至300 nm之间的生物学显著波长下产生。在该范围以上或以下仅检测到低水平。嘌呤光产物的形成是剂量依赖性的，在某些特定位点的产量与嘧啶二聚体相似。这些结果表明，含嘌呤的光产物可能是紫外线致癌的后果。
The formation of DNA base damages by broad spectrum ultraviolet irradiation (250–400 nm) was investigated using a defined sequence of human DNA. The irradiated, 92 base pair, 3‐end of the human alphoid segment was incubated with an enzyme fraction purified from bacteriophage T4‐infectedE. coli.As previously reported, analysis of reaction products by sequencing gels showed enzymic incision of purine‐containing photoproducts as well as pyrimidine cyclobutane photodimers. The purine‐incising activity does not require metal ions and was unaffected by β‐mercaptoethanol or dithiothreitol. The formation of the purine photoproducts is independent of buffer; these lesions are produced by irradiation of DNA in Tris, Hepes or phosphate buffers. They are produced at biologically significant wavelengths between 260 to 300 nm. Only low levels were detected above or below this range. The formation of purine photoproducts is dose dependent with similar yields at some specific loci to pyrimidine dimers. These results suggest that purine‐containing photoproducts could be of consequence in ultraviolet carcinogenesis.