Characterization and application of a DNA aptamer binding to L-tryptophan
Characterization and application of a DNA aptamer binding to L-tryptophan
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与 L-色氨酸结合的 DNA 适体的表征和应用
DOI：
10.1039/c0an00550a
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发表时间：
2011-01-01
期刊：
影响因子：
4.2
通讯作者：
Shangguan, Dihua
中科院分区：
文献类型：
--
作者：
Yang, Xiaojuan;Bing, Tao;Shangguan, Dihua
通过指数富集配体的系统进化（SELEX）技术，已经进化出特异性识别l -色氨酸的DNA适体。截断突变实验表明，Trp3a-1序列与l -色氨酸的结合能力最强。预测Trp3a-1将采用环-茎二级结构，其中环可能在茎的帮助下进一步折叠成l -色氨酸的结合袋。特异性研究表明，Trp3a-1与l -色氨酸结合较强，与其他氨基酸几乎不结合，与一些含有l -色氨酸残基的色氨酸类似物和多肽结合较弱。Trp3a-1与l -色氨酸的结合主要是通过Trp3a-1的结合口袋与l -色氨酸上的所有基团之间形成氢键和精确堆叠来实现的。该适配体也被证明是D/ l -色氨酸手性分离的有效配体。l -色氨酸及其衍生物具有重要的生物学作用；该配体可作为色氨酸分析及其他相关研究的工具。
DNA aptamers for specific recognition of L-tryptophan have been evolved by a SELEX (systematic evolution of ligands by exponential enrichment) technique. Truncation-mutation experiments suggest that a 34-mer sequence, Trp3a-1, possesses the strongest binding ability to L-tryptophan. Trp3a-1 is predicted to adopt a loop-stem secondary structure, in which the loop may further fold into a binding pocket for L-tryptophan with the help of the stem. The specificity investigation shows that Trp3a-1 strongly binds to L-tryptophan, has almost no binding to other amino acids, and weakly binds to some tryptophan analogs and peptides containing the L-tryptophan residue. The binding of Trp3a-1 to L-tryptophan is mainly contributed to by hydrogen bonds and precise stacking formed between the binding pocket of Trp3a-1 and all groups on L-tryptophan. This aptamer has also been proved to be an effective ligand for the chiral separation of D/L-tryptophan. L-Tryptophan and its derivatives are known to play important biological roles; this aptamer ligand could be used as a tool for the analysis of tryptophan and other related studies.