Bartoszek A, Dackiewicz P, Składanowski A, Konopa J
Department of Pharmaceutical Technology and Biochemistry, Technical University of Gdańsk, Poland.
Chem Biol Interact. 1997 Feb 28;103(2):141-51. doi: 10.1016/s0009-2797(96)03754-4.
Using agarose gel electrophoresis we confirmed that Ledakrin is capable of incurring covalent crosslinking in pBR322 plasmid DNA and also in poly(dGdC) in the presence of a simple activating system containing DTT. The identification of adducts resulting from DNA crosslinking was carried out by 32P-post-labelling assay. We assumed that such adduct(s) should be brought about more readily with double-stranded than with single-stranded polynucleotides or nucleotides. Since our earlier experiments had shown that guanine is a major site of covalent binding of 1-nitroacridines, we compared DNA adduct formation by Ledakrin for ctDNA, dG-containing synthetic homopolymers and 3'-pdG. 32P-Post-labelling assay revealed two adduct spots that were enhanced in samples containing double-stranded substrates in which interstrand crosslinking between guanines was possible, namely ctDNA and poly(dGdC).
通过琼脂糖凝胶电泳，我们证实了在含有二硫苏糖醇（DTT）的简单激活系统存在的情况下，利达克林（Ledakrin）能够使pBR322质粒DNA以及聚（dGdC）发生共价交联。通过³²P后标记分析法对DNA交联产生的加合物进行了鉴定。我们认为，与单链多核苷酸或核苷酸相比，双链多核苷酸形成此类加合物应该更容易。由于我们早期的实验表明鸟嘌呤是1-硝基吖啶共价结合的主要位点，因此我们比较了利达克林对小牛胸腺DNA（ctDNA）、含dG的合成均聚物和3'-磷酸鸟苷（3'-pdG）形成DNA加合物的情况。³²P后标记分析法显示出两个加合物斑点，在含有双链底物的样品中这两个斑点增强，在双链底物中鸟嘌呤之间可能发生链间交联，即ctDNA和聚（dGdC）。
