Human telomeric hybrid-2-over-hybrid-1G-quadruplex targeting and a selective hypersaline-tolerant sensor using abasic site-engineered monomorphism
Human telomeric hybrid-2-over-hybrid-1G-quadruplex targeting and a selective hypersaline-tolerant sensor using abasic site-engineered monomorphism
复制标题
人类端粒杂合2超杂合1G四链体靶向和使用脱碱基位点工程单态性的选择性耐高盐传感器
DOI：
10.1016/j.aca.2017.01.041
复制
发表时间：
2017
影响因子：
6.2
通讯作者：
Yong Shao
中科院分区：
文献类型：
--
作者：
Tao Wu;meiyun Ye;Tianyi Mao;Fan Lin;Yuehua Hu;Ning Gan;Yong Shao
人类端粒g -四重体形成序列（htG4）的多态杂交-1和杂交-2构象的共存使其精细结构鉴定复杂化，限制了其作为传感器元件的应用。利用碱基位点（AP位点）修饰的htG4s作为两种典型杂交构象的单态代表，我们发现硫黄素T （ThT）在单体和串联htG4分子中可以选择性地靶向杂交-2构象，而不是杂交-1构象。仅采用AP位点设计的单态杂交-2构象的htG4在K+中最有效地照亮ThT荧光，并且实现了选择性K+传感器，具有显着的耐高盐能力，甚至可以在超过30,000倍的Na+中工作。在600 mM Na+下，K+检测的动态范围可以扩展到30 mM，检测限为20 μM。这是htG4这两种杂化构象的荧光识别的首次报道，尽管它们长期以来一直被分类为具有其特征的结构拓扑。我们的工作将引起人们对基于单态htG4共形器的传感器开发的极大兴趣，因为以前从未实现过如此高性能的传感器开发。
Coexistence of the polymorphic hybrid-1 and hybrid-2 conformers for a given human telomeric G-quadruplex-forming sequence (htG4) complicates its fine structure identification and limits its application as a sensor element. With help from abasic site (AP site)-engineered htG4s serving as the monomorphic representatives of the two typical hybrid conformers, we found that thioflavin T (ThT) can selectively target the hybrid-2 conformer over the hybrid-1 counterpart in monomer and tandem htG4 molecules. The htG4 that solely adopts the monomorphic hybrid-2 conformer engineered by the AP site is most efficient in lighting up ThT fluorescence in K+and a selective K+sensor is realized with a remarkable hypersaline-tolerant capability that can work even in 30000-fold excess of Na+. At 600 mM Na+, the dynamic range for K+detection can be extended to 30 mM with the limit of detection of 20 μM. This is the first report on the fluorescence discrimination of these two hybrid conformers of htG4 although they have long been categorized with their characteristically structural topologies. Our work will attract much interest in the development of sensors based on the monomorphic htG4 conformer since such high performance in sensor development has not been previously achieved.