Chen Wen, Komiyama Makoto
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
Chembiochem. 2005 Oct;6(10):1825-30. doi: 10.1002/cbic.200500119.
Two deoxyuridine derivatives each bearing a monophosphate group at the 5-position with a C3 linker, were incorporated into an oligonucleotide. By using this modified oligonucleotide, a bulge was formed at a predetermined position in a DNA substrate, and two monophosphate groups were placed at both junctions of the bulge. Upon treatment of the mixture with Ce(IV)-EDTA at pH 7.0, the phosphodiester linkages at the bulge site were selectively and efficiently hydrolyzed. The monophosphate groups introduced into the bulge site greatly accelerated site-selective DNA scission. Compared with the previously reported two-additive system, which combines two oligonucleotide additives each with a monophosphate at their termini, the present one-additive system is simpler and more convenient. Furthermore, site-selective DNA hydrolysis by using this one-additive system is successful even at high reaction temperatures (e.g., 55 degrees C). This reflects the thermodynamic stability of the duplexes formed between the substrate and the additive DNA.
两种在5位带有单磷酸基团且带有C3连接基的脱氧尿苷衍生物被掺入到寡核苷酸中。通过使用这种修饰的寡核苷酸，在DNA底物的预定位置形成了一个凸起，并且在凸起的两个连接处都放置了两个单磷酸基团。在pH 7.0条件下用Ce(IV)-EDTA处理该混合物时，凸起部位的磷酸二酯键被选择性且高效地水解。引入到凸起部位的单磷酸基团极大地加速了位点选择性DNA断裂。与先前报道的双添加剂系统（该系统将两种在末端均带有单磷酸的寡核苷酸添加剂结合在一起）相比，本单添加剂系统更简单、更方便。此外，使用这种单添加剂系统进行位点选择性DNA水解即使在高反应温度（例如55℃）下也能成功。这反映了底物与添加剂DNA之间形成的双链体的热力学稳定性。
