Fluorescent amplifying recognition for DNA G-quadruplex folding with a cationic conjugated polymer: A platform for homogeneous potassium detection
Fluorescent amplifying recognition for DNA G-quadruplex folding with a cationic conjugated polymer: A platform for homogeneous potassium detection
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DOI：
10.1021/ja051507i
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发表时间：
2005-09-07
影响因子：
15
通讯作者：
Zhu, DB
中科院分区：
文献类型：
--
作者：
He, F;Tang, YL;Zhu, DB
具有富含G序列的单链DNA可以通过分子内氢键相互作用折叠成二级结构，G-四链体。这种构象变化可以通过均相测定方法检测，该方法基于从水溶性阳离子共轭聚合物（CCP）到标记在G-四链体DNA末端的荧光素发色团的荧光共振能量转移（FRET）。DNA周围的空间电荷密度控制从CCP到荧光素的FRET效率。CCP/G-四链体对的更高FRET效率与更浓缩的G-四链体和CCP之间的静电相互作用比CCP/ssDNA对更强相关。由于钾离子可以特异性地与G-四链体DNA结合，因此G-四链体DNA/CCP组装体也可以用作高选择性和灵敏度地检测水中钾离子的平台。
Single-stranded DNA with G-rich sequences can fold into secondary structures, G-quadruplexes, via intramolecular hydrogen-bonding interactions. This conformational change can be detected by a homogeneous assay method based on fluorescence resonance energy transfer (FRET) from a water-soluble cationic conjugated polymer (CCP) to a fluorescein chromophore labeled at the terminus of the G-quadruplex DNA. The space charge density around the DNA controls the efficiency of FRET from the CCP to the fluorescein. The higher FRET efficiency for the CCP/G-quadruplex pair is correlated to the stronger electrostatic interactions between the more condensed G-quadruplex and the CCP in comparison to the CCP/ssDNA pair. Since the potassium ion can specifically bind to the G-quadruplex DNA, the G-quartet-DNA/CCPs assembly can also be used as a platform to sense the potassium ion in water with high selectivity and sensitivity.