Quinoxaline antibiotics enhance peptide nucleic acid binding to double-stranded DNA
Quinoxaline antibiotics enhance peptide nucleic acid binding to double-stranded DNA
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DOI：
10.1021/bi000254x
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发表时间：
2000-08-08
期刊：
影响因子：
2.9
通讯作者：
Nielsen, PE
中科院分区：
文献类型：
--
作者：
Mollegaard, NE;Bailly, C;Nielsen, PE
用凝胶滞留分析法研究了多种DNA结合药物对肽核酸(PNA)链置换结合双链DNA的影响。双-PNA[H-(Lys)-TTJTTJTTTTT-(Eg)(3)-TTTTCTTCTT-Lys-NH2]与包含PNA合适靶点的248个核苷酸片段一起使用。所研究的大多数配体，包括DNA小槽结合剂以及嵌入剂和双嵌入剂，对PNA与DNA的结合没有影响或强烈抑制。相比之下，喹恶啉抗生素促进了PNA-DNA复合体的形成。利用时间和温度依赖性实验对棘霉素的PNA辅助作用进行了较为详细的研究，以阐明其作用机制。PNA与DNA的结合遵循准一级动力学，但在10亩的棘球菌素存在下，结合的初始速度加快了10倍以上。抗生素使PNA与dsDNA结合的活化能降低2倍(对照组为45kJ/mol比90kJ/mol)。喹恶啉促进PNA与DNA结合的原因尚不完全清楚，但很可能包括促进PNA入侵的双螺旋扭曲(打开)。这项研究证明，通过明智地添加某些DNA相互作用的配体，可以潜在地提高DNA靶向的PNA抗基因分子的效力。
The effects of a wide range of DNA binding drugs on peptide nucleic acid (PNA) binding to double-stranded DNA by strand displacement have been investigated using a gel retardation assay. The bis-PNA [H-(Lys)-TTJTTJTTTT-(eg)(3) -TTTTCTTCTT-Lys-NH2] was used together with a 248 bp DNA fragment containing an appropriate target for the PNA. Most of the ligands that were studied, including DNA minor groove binders as well as intercalators and bis-intercalators, either have no effect or strongly inhibit PNA binding to DNA. By contrast, quinoxaline antibiotics facilitate PNA-DNA complex formation. The "PNA-helper" effect of echinomycin was studied in more detail using time and temperature dependence experiments to elucidate the mechanism. PNA binding to DNA follows pseudo-first-order kinetics, but the initial rate of binding is accelerated more than 10-fold in the presence of 10 mu M echinomycin. The activation energy for PNA binding to dsDNA is lowered 2-fold by the antibiotic (45 vs 90 kJ/mol in the control). The reasons why quinoxalines promote the binding of PNA to DNA are not entirely clear but may well include distortions (opening) of the double helix that facilitate PNA invasion. This study establishes that the efficacy of DNA-targeted PNA antigene molecules could potentially be enhanced by judiciously adding certain DNA-interactive ligands.