Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
Chemistry. 2010 Jan 18;16(3):855-9. doi: 10.1002/chem.200902169.
Oligodeoxyribonucleotide conjugates of ethylenediamine-N,N,N',N'-tetrakis(methylenephosphonic acid) (EDTP) have been used to place a Ce(III)/EDTP complex in close proximity to predetermined phosphodiester linkages of a complementary target oligonucleotide. In the presence of atmospheric oxygen, the Ce(III) is oxidized into Ce(IV) which, in turn, efficiently cleaves the target phosphodiester linkage. No cleavage occurs at the other single-stranded regions, which suggests that the catalytic Ce species is strictly localized next to the target phosphodiester linkage. No decrease in the reaction rate is observed upon introduction of scavengers for hydroxyl radicals (such as DMSO or MeOH) or singlet oxygen (such as NaN(3)) to the system; this indicates that the reaction proceeds via a hydrolytic pathway. Any significant contribution by an oxidative pathway is further ruled out by the observation that nucleosides remain intact after incubation with Ce(IV)/EDTP complex for extended periods.
乙二胺-N,N,N',N'-四（亚甲基膦酸）（EDTP）的寡核苷酸缀合物已被用于将 Ce(III)/EDTP 配合物放置在互补靶寡核苷酸的预定磷酸二酯键附近。在大气氧的存在下，Ce(III)被氧化成 Ce(IV)，后者反过来有效地切割靶磷酸二酯键。在其他单链区域不会发生切割，这表明催化 Ce 物种严格定位于靶磷酸二酯键附近。向体系中引入羟基自由基（如 DMSO 或 MeOH）或单线态氧（如 NaN(3)）的清除剂后，反应速率没有降低；这表明反应通过水解途径进行。核昔酸在与 Ce(IV)/EDTP 配合物孵育延长时间后保持完整，这进一步排除了氧化途径的显著贡献。
