DNA Binding of A D‐Lysine‐Based Chiral PNA: Direction Control and Mismatch Recognition
DNA Binding of A D‐Lysine‐Based Chiral PNA: Direction Control and Mismatch Recognition
复制标题
基于 D-赖氨酸的手性 PNA 的 DNA 结合：方向控制和错配识别
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
R. Marchelli
中科院分区：
文献类型：
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作者：
S. Sforza;R. Corradini;S. Ghirardi;A. Dossena;R. Marchelli
肽核酸（PNAs）是由N-（2-氨基乙基）甘氨酸单元构成骨架的寡核苷酸类似物；它们与互补的DNA和RNA结合，具有很高的稳定性和特异性。为了提高结合特异性、溶解度和细胞摄取，已经引入了许多修饰，其中一些涉及引入立体中心。为了实现与DNA的选择性反平行结合，我们在本文中报道了一种手性PNA十聚体（H-GTAGATCACT-NH2）的合成和结合能力，该十聚体在链的中间含有三个基于d - lys的单体（一个“手性盒子”）。事实上，反平行的PNA-DNA双链显示熔点为43°C（通过CD和UV光谱确定），而平行的PNA-DNA双链无法形成，这表明在UV和CD光谱中没有温度依赖性。此外，与具有单个错配的反平行DNA链进行的杂交实验表明，该PNA在错配和匹配目标之间具有出色的区分能力。这些结果表明，PNA序列中间的高手性约束强烈影响DNA络合的方向选择性，即DNA络合中的反平行/平行偏好。特别是，“d -手性盒子”有利于高度特异性的反平行DNA结合，从而允许可能的诊断应用于筛选单点突变。
Peptide nucleic acids (PNAs) are oligonucleotide analogues with a skeleton made up of N-(2-aminoethyl)glycine units; they bind to complementary DNA and RNA with high stability and specificity. In order to improve the binding specificity, solubility and uptake into cells, many modifications have been introduced, some concerning the introduction of stereogenic centres. With the aim of achieving a selective antiparallel binding with DNA, we report in this paper the synthesis and binding abilities of a chiral PNA decamer (H-GTAGATCACT-NH2) bearing three D-Lys-based monomers (a “chiral box”) in the middle of the strand. Indeed, the antiparallel PNA-DNA duplex showed a melting point of 43 °C (determined both by CD and UV spectroscopy), whereas the parallel PNA-DNA duplex failed to form, as shown by the absence of temperature dependence in the UV and CD spectra. Moreover, hybridization experiments carried out with antiparallel DNA strands bearing single mismatches showed that this PNA was excellent in discriminating between mismatched and matched targets. These results indicate that a high chiral constraint in the middle of a PNA sequence strongly affects the direction selectivity, i.e. the antiparallel/parallel preference in the DNA complexation. In particular, a “D-chiral box” favours a highly specific antiparallel DNA binding, thus allowing possible diagnostic applications for the screening of single-point mutations.