STRAND-INVASION OF DUPLEX DNA BY PEPTIDE NUCLEIC-ACID OLIGOMERS
STRAND-INVASION OF DUPLEX DNA BY PEPTIDE NUCLEIC-ACID OLIGOMERS
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DOI：
10.1073/pnas.90.22.10648
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发表时间：
1993-11-15
影响因子：
11.1
通讯作者：
BABISS, LE
中科院分区：
文献类型：
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作者：
PEFFER, NJ;HANVEY, JC;BABISS, LE
聚酰胺寡聚物，称为肽核酸 (PNA)，以高亲和力与 DNA 和 RNA 结合，并提供反义和反基因方法来调节基因表达。当 PNA 与双链 DNA 中的互补序列结合时，双链体的一条链被置换，并形成稳定的 D 环。与结合极性由脱氧核糖决定的寡脱氧核苷酸不同，PNA 的不受限制的聚酰胺主链可以允许以方向无关的方式与 DNA 靶标结合。我们现在提供的证据表明，PNA 实际上可以与 DNA 中的互补序列结合，而不受 DNA 链极性的影响，也就是说，PNA 以“平行”和“反平行”方式与 DNA 结合。对于混合序列 15 聚体 PNA，PNA-DNA 相互作用的动力学研究表明，D 环形成迅速，且复合物可稳定数小时。然而，当通过凝胶迁移率变化分析或 RNA 聚合酶 II 延伸终止进行测量时，D 环的形成是盐依赖性的，但 PNA 链解离不是盐依赖性的。我们观察到含有 D 环的 DNA 片段具有异常的凝胶迁移率，该迁移率随 D 环相对于 DNA 末端的位置而变化。根据排列分析，PNA.DNA 复合物的迁移率降低归因于 D 环处或附近的 DNA 弯曲。
Polyamide oligomers, termed peptide nucleic acids (PNAs), bind with high affinity to both DNA and RNA and offer both antisense and antigene approaches for regulating gene expression. When a PNA binds to a complementary sequence in a double-stranded DNA, one strand of the duplex is displaced, and a stable D-loop is formed. Unlike oligodeoxynucleotides for which binding polarity is determined by the deoxyribose sugar, the unrestrained polyamide backbone of the PNA could permit binding to a DNA target in an orientation-independent manner. We now provide evidence that PNAs can, in fact, bind to their complementary sequence in DNA independent of the DNA-strand polarity-that is, a PNA binds to DNA in both ''parallel'' and ''antiparallel'' fashion. With a mixed-sequence 15-mer PNA, kinetic studies of PNA-DNA interactions revealed that D-loop formation was rapid and the complex was stable for several hours. However, when measured either by gel-mobility-shift analysis or RNA polymerase II-elongation termination, D-loop formation was salt dependent, but PNA-strand dissociation was not salt dependent. We observed that D-loop-containing DNA fragments had anomalous gel mobilities that varied as a function of the position of the D-loop relative to the DNA termini. On the basis of permutation analysis, the decreased mobility of the PNA.DNA complex was attributed to a bend in the DNA at or near the D-loop.