作者:Ligang Zhang、Hai Long、Grant E. Boldt、Kim D. Janda、George C. Schatz、Frederick D. Lewis
DOI:10.1039/b513694f
日期:——
The synthesis, structure, and optical spectroscopy of hairpin oligonucleotide conjugates possessing synthetic stilbene C-nucleosides (stilbenosides) are reported. Synthetic methods for selective preparation of both the α- and β-stilbenosides have been developed. Both anomers are effective in stabilizing hairpin structures when used as capping groups at the open end of the hairpin base-pair domain. However, only the β-anomer effectively stabilizes the hairpin structure when located in the interior of the base-pair domain opposite an abasic site. Similar results are obtained for hairpins possessing two stilbenosides, either adjacent to each other or with one intervening base-pair. Molecular dynamics simulations are employed to obtain averaged structures for these conjugates. The calculated structures for the capped hairpins formed with either anomer show effective Ï-stacking with the adjacent base-pair. The calculated structures for the internal stilbenosides show that the α- and β-anomers form extrahelical and intrahelical structures, respectively. The relative orientations of the two stilbenes in the bis-stilbenosides have been studied using a combination of exciton-coupled circular dichroism spectroscopy and molecular modeling.
报道了具有合成二苯乙烯 C-核苷(二苯乙烯苷)的发夹寡核苷酸缀合物的合成、结构和光谱。已经开发了选择性制备α-和β-二苯乙烯苷的合成方法。当用作发夹碱基对结构域开放端的封端基团时,两种端基异构体均可有效稳定发夹结构。然而,只有β-端基异构体位于与脱碱基位点相对的碱基对域内部时,才能有效稳定发夹结构。对于具有两个二苯乙烯苷(彼此相邻或具有一个插入碱基对)的发夹,获得了类似的结果。采用分子动力学模拟来获得这些缀合物的平均结构。由任一端基对形成的加帽发夹的计算结构显示出与相邻碱基对的有效α-堆积。内部二苯乙烯苷的计算结构表明α-和β-端基异构体分别形成螺旋外和螺旋内结构。结合激子耦合圆二色性光谱和分子建模研究了双二苯乙烯苷中两种二苯乙烯的相对取向。