DNA probes for the studies of damaged strand excision during the nucleotide excision repair (NER) have been designed using the novel non-nucleosidic phosphoramidite reagents that contain N-[6-(9-antracenylcarbamoyl)hexanoyl]-3-amino-1,2-propandiol (nAnt) and N-[6-(5(6)-fluoresceinylcarbamoyl)hexanoyl]-3-amino-1,2-propandiol (nFlu) moieties. New lesion-imitating adducts being inserted into DNA show good substrate properties in NER process. Modified extended linear nFlu– and nAntr–DNA are suitable for estimation of specific excision activity catalysed with mammalian whole-cell extracts. The following substrate activity range was revealed for the model 137-bp linear double-stranded DNA: nAnt–DNA ≈ nFlu–DNA > Chol–DNA (Chol–DNA—legitimate NER substrate that contains non-nucleoside fragment bearing cholesterol residue). In vitro assay shows that modified DNA can be a useful tool to study NER activity in whole-cell extracts. The developed approach should be of general use for the incorporation of NER-sensitive distortions into model DNAs. The new synthetic extended linear DNA containing bulky non-nucleoside modifications will be useful for NER mechanism study and for applications.
利用新型非核苷
磷酰胺试剂设计了用于研究核苷酸切除修复(NER)过程中受损链切除的 DNA 探针,这些试剂含有 N-[6-(9-
蒽基
氨基甲酰基)己酰基]-
3-氨基-1,2-丙二醇(nAnt)和 N-[6-(5(6)-
荧光素基
氨基甲酰基)己酰基]-
3-氨基-1,2-丙二醇(nFlu)分子。插入 DNA 的新病变模拟加合物在 NER 过程中显示出良好的底物特性。经修饰的扩展线性 nFlu- 和 nAntr-DNA 适用于估计哺乳动物全细胞
提取物催化的特异性切除活性。对于 137-bp 的线性双链 DNA 模型,底物活性范围如下:nAnt-DNA ≈ nFlu-DNA > Chol-DNA(Chol-DNA--含有
胆固醇残基的非核苷片段的合法 NER 底物)。体外试验表明,修饰 DNA 是研究全细胞
提取物中 NER 活性的有用工具。所开发的方法可用于在模型 DNA 中加入对 NER 敏感的畸变。含有大块非核苷修饰的新合成扩展线性 DNA 将有助于 NER 机制研究和应用。