Torigoe H, Akaike T, Maruyama A
Institute of Physical and Chemical Research (RIKEN), 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
Nucleic Acids Res Suppl. 2001(1):195-6. doi: 10.1093/nass/1.1.195.
In the present study, we describe rapid formation of stable pyrimidine motif triplex at physiological pH. The triplex formation was achieved by the synergistic effect of poly(L-lysine)-graft-dextran (PLL-g-Dex) copolymer and N3'-->P5' phosphoramidate (PN) backbone modification of triplex-forming oligonucleotide (TFO). Either the PLL-g-Dex copolymer or the PN modification alone increased the binding constant by nearly two orders of magnitude for the triplex formation at neutral pH. The combination of both stabilizing factors that was the triplex formation with the PN TFO in the presence of the copolymer increased the binding constant by nearly four orders of magnitude. The kinetic study indicated that the copolymer increased the association rate constant, whereas the PN modification decreased the dissociation rate constant. No negative interference between these stabilizing effects was observed. The kinetically orchestrated effects in which the copolymer and the PN TFO contribute to distinct ingredients in triplex equilibrium achieved the rapid formation of the stable triplex.
在本研究中，我们描述了在生理pH条件下稳定嘧啶基序三链体的快速形成。三链体的形成是通过聚（L-赖氨酸）-接枝-葡聚糖（PLL-g-Dex）共聚物与三链体形成寡核苷酸（TFO）的N3'→P5'氨基磷酸酯（PN）主链修饰的协同作用实现的。单独的PLL-g-Dex共聚物或PN修饰在中性pH条件下使三链体形成的结合常数增加了近两个数量级。这两种稳定因素的组合，即在共聚物存在下用PN TFO形成三链体，使结合常数增加了近四个数量级。动力学研究表明，共聚物增加了缔合速率常数，而PN修饰降低了解离速率常数。未观察到这些稳定作用之间的负干扰。共聚物和PN TFO在三链体平衡中对不同成分起作用的动力学协调效应实现了稳定三链体的快速形成。
