Hybridization of complementary and homologous peptide nucleic acid oligomers to a guanine quadruplex-forming RNA
Hybridization of complementary and homologous peptide nucleic acid oligomers to a guanine quadruplex-forming RNA
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DOI：
10.1021/bi051831q
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发表时间：
2006-02-14
期刊：
影响因子：
2.9
通讯作者：
Armitage, BA
中科院分区：
文献类型：
--
作者：
Marin, VL;Armitage, BA
以鸟嘌呤四链形成RNA为靶标的多肽核酸(PNA)低聚物可以两种不同的方式进行设计。首先，互补的富含胞嘧啶的PNA可以通过形成Watson-Crick碱基对进行杂交，从而产生杂交的PNA-RNA双链。其次，富含鸟嘌呤的同源PNA可以通过形成G四分体进行杂交，从而产生杂交的PNA-RNA四联体。通过UV热变性、圆二色谱和荧光光谱实验比较了两种识别模式，发现互补的PNA形成1：1的双链，同源的PNA形成2：1的四链。这两个杂交种都非常稳定，并且在低纳摩尔浓度下观察到杂交。无论PNA链的极性如何，杂交四链的形成都是同样有效的，这表明PNA和RNA链上的环核苷酸碱基之间缺乏相互作用。这一发现对序列特异性的影响以及提高亲和力的方法也进行了讨论。
Peptide nucleic acid (PNA) oligomers targeted to guanine quadruplex-forming RNAs can be designed in two different ways. First, complementary cytosine-rich PNAs can hybridize by the formation Of Watson-Crick base pairs, resulting in hybrid PNA-RNA duplexes. Second, guanine-rich homologous PNAs can hybridize by the formation of G tetrads, resulting in hybrid PNA-RNA quadruplexes. UV thermal denaturation, circular dichroism, and fluorescence spectroscopy experiments were used to compare these two recognition modes and revealed 1: 1 duplex formation for the complementary PNA and 2:1 (PNA(2)-RNA) quadruplex formation for the homologous PNA. Both hybrids were very stable, and hybridization was observed at low nanomolar concentrations. Hybrid quadruplex formation was equally efficient regardless of the PNA strand polarity, indicating a lack of interaction between the loop nucleobases on the PNA and RNA strands. The implications of this finding on sequence specificity as well as methods to improve affinity are also discussed.