Lönnberg Tuomas, Suzuki Yuta, Komiyama Makoto
Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
Org Biomol Chem. 2008 Oct 7;6(19):3580-7. doi: 10.1039/b807789d. Epub 2008 Jul 16.
Oligodeoxyribonucleotide multiphosphonate conjugates have been prepared by on-support oximation of aminooxy-functionalized oligonucleotides with 2-(4-formylphenoxy)ethyl esters of nitrilotris(methylenephosphonic acid) (NTP) and ethylenediaminetetrakis(methylenephosphonic acid) (EDTP). These conjugates, along with the corresponding oligonucleotides bearing hydroxy or monophosphate termini, were hybridized with a longer substrate DNA leaving a narrow single-stranded gap site in the substrate between the two additive oligonucleotides. Gap sites flanked by two of the multiphosphonate groups, in particular EDTP, were hydrolyzed by the Ce(IV)-EDTA complex significantly faster than the corresponding gap sites flanked by only hydroxy or monophosphate termini. Using the new oligonucleotide conjugates, efficient site-selective hydrolysis of the substrate DNA can be achieved at Ce(IV) concentrations where other single-stranded regions remain intact. At high Ce(IV) concentrations, the cleavage rate becomes independent on [Ce(IV)] and little improvement by the new multiphosphonate conjugates over oligonucleotides with monophosphate termini is observed, suggesting that the origin of the rate acceleration is the higher affinity of the NTP or EDTP ligands to Ce(IV) compared to hydroxy or monophosphate ligands.
通过用次氮基三（亚甲基膦酸）（NTP）和乙二胺四（亚甲基膦酸）（EDTP）的2-（4-甲酰基苯氧基）乙酯对氨氧基官能化的寡核苷酸进行载体上的肟化反应，制备了寡脱氧核糖核苷酸多膦酸酯缀合物。这些缀合物，以及带有羟基或单磷酸末端的相应寡核苷酸，与更长的底物DNA杂交，在两种添加的寡核苷酸之间的底物中留下一个狭窄的单链缺口位点。两侧带有两个多膦酸酯基团（特别是EDTP）的缺口位点被Ce（IV）-EDTA络合物水解的速度明显快于仅两侧带有羟基或单磷酸末端的相应缺口位点。使用新的寡核苷酸缀合物，在Ce（IV）浓度下可以实现底物DNA的高效位点选择性水解，而其他单链区域保持完整。在高Ce（IV）浓度下，裂解速率变得与[Ce（IV）]无关，并且未观察到新的多膦酸酯缀合物比具有单磷酸末端的寡核苷酸有太大改善，这表明速率加速的原因是NTP或EDTP配体与Ce（IV）的亲和力高于羟基或单磷酸配体。
