Laboratory for Organic and Biomimetic Chemistry, University of Ghent, Krijgslaan 281 S4, B-9000 Ghent, Belgium.
J Am Chem Soc. 2011 Feb 2;133(4):796-807. doi: 10.1021/ja1048169. Epub 2010 Dec 16.
Chemical reagents that form interstrand cross-links have been used for a long time in cancer therapy. They covalently link two strands of DNA, thereby blocking transcription. Cross-link repair enzymes, however, can restore the transcription processes, causing resistance to certain anti-cancer drugs. The mechanism of these cross-link repair processes has not yet been fully revealed. One of the obstacles in this study is the lack of sufficient amounts of well-defined, stable, cross-linked duplexes to study the pathways of cross-link repair enzymes. Our group has developed a cross-link strategy where a furan moiety is incorporated into oligodeoxynucleotides (ODNs). These furan-modified nucleic acids can form interstrand cross-links upon selective furan oxidation with N-bromosuccinimide. We here report on the incorporation of the furan moiety at the 2'-position of a uridine through an amido or ureido linker. The resulting modified ODNs display an unprecedented selectivity for cross-linking toward a cytidine opposite the modified residue, forming one specific cross-linked duplex, which could be isolated in good yield. Furthermore, the structure of the formed cross-linked duplexes could be unambiguously characterized.
用于癌症治疗的化学试剂已经在很长一段时间内形成链间交联。它们使两条 DNA 链共价连接，从而阻断转录。然而，交联修复酶可以恢复转录过程，导致对某些抗癌药物的耐药性。这些交联修复过程的机制尚未完全揭示。这项研究中的一个障碍是缺乏足够数量的定义明确、稳定的交联双链体来研究交联修复酶的途径。我们的小组开发了一种交联策略，其中将呋喃部分掺入寡脱氧核苷酸（ODN）中。这些呋喃修饰的核酸可以通过与 N-溴代丁二酰亚胺选择性地氧化呋喃来形成链间交联。我们在这里报告了通过酰胺或脲基连接体在尿嘧啶的 2'位引入呋喃部分。所得修饰的 ODN 对修饰残基对面的胞嘧啶表现出前所未有的交联选择性，形成一种特定的交联双链体，可以高产率分离。此外，可以明确表征形成的交联双链体的结构。
