Structural features of the L-argininamide-binding DNA aptamer studied with ESI-FTMS
Structural features of the L-argininamide-binding DNA aptamer studied with ESI-FTMS
复制标题
利用 ESI-FTMS 研究 L-精氨酰胺结合 DNA 适体的结构特征
DOI：
10.1021/ac060606r
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发表时间：
2006-10-15
影响因子：
7.4
通讯作者：
Bruist, Michael F.
中科院分区：
文献类型：
--
作者：
Guo, Xinhua;Liu, Zhiqiang;Bruist, Michael F.
Harada和Frankel的24-mer DNA适体（Harada，K.; Frankel，A. D. EMBO J. 1995，14，5798-5811）通过电喷雾电离傅里叶变换质谱法（ESI-FTMS）研究了结合L-烟酰胺（L-Arm）的化合物。作为对照，研究了相同碱基组成的两种衍生物，一种具有相同的茎但具有乱序环，另一种没有形成二级结构的能力。与线性对照相比，可以折叠成茎环结构的两种DNA显示出更负电荷的离子分布。这种趋势在配体的存在下得以保持;预期具有更多二级结构的复合物具有带更多负电荷的离子。对于每个DNA，观察到对应于没有、一个和两个结合的L-臂分子的不同种类。将分数峰强度拟合到直接结合模型，并获得结合常数。因此，ESI-FTMS可以提供有关DNA结构及其与非共价配体相互作用的定性和定量数据。
The 24-mer DNA aptamer of Harada and Frankel ( Harada, K.; Frankel, A. D. EMBO J. 1995, 14, 5798-5811) that binds L-argininamide (L-Arm) was studied by electrospray ionization Fourier transform mass spectrometry (ESI-FTMS). This DNA folds into a stem and loop such that the loop is able to engulf L-Arm. As controls, two derivatives of the same base composition, one with the same stem but a scrambled loop and the other with no ability to form a secondary structure, were studied. The two DNAs that could fold into stem-loop structures showed a more negatively charged distribution of ions than the linear control. This tendency was preserved in the presence of ligand; complexes expected to have more secondary structure had ions with more negative charges. Distinct species corresponding to no, one, and two bound L-Arm molecules were observed for each DNA. The fractional peak intensities were fit to a straightforward binding model and binding constants were obtained. Thus, ESI-FTMS can provide both qualitative and quantitative data regarding the structure of DNA and its interactions with noncovalent ligands.