Ye Mei-Yun, Zhu Rui-Tao, Li Xiang, Zhou Xiao-Shun, Yin Zheng-Zhi, Li Qian, Shao Yong
Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University , Jinhua 321004, Zhejiang, China.
Department of Chemistry, Taiyuan Normal University , Taiyuan 030031, China.
Anal Chem. 2017 Sep 5;89(17):8604-8608. doi: 10.1021/acs.analchem.7b02467. Epub 2017 Aug 21.
Besides the canonical Watson-Crick (WC) linked antiparallel-stranded duplex (aps-DNA), DNA is also able to form bioactive parallel-stranded duplex (ps-DNA) with the two involving strands adopting the equal 5'-3' polarity. Discriminating ps-DNA from aps-DNA with an ideal selectivity is more challenging because of their comparable duplex topologies. Herein, we designed a unique probe of HPIN to fluorescently recognize ps-DNA but to keep an almost nonfluorescent response in binding with aps-DNA. The success of the Hoogsteen hydrogen bonding pattern in lighting up the HPIN fluorescence over the reverse Watson-Crick (rWC) one suggests the critical role of HPIN in structurally adaptive recognition to the strand polarity-determined base-pairing peculiarity. The turn-on fluorescence should result from restriction of the HPIN cis/trans isomerization upon the adaptive Hoogsteen base pair binding. Such high performance in recognizing ps-DNA against aps-DNA demonstrates the promising applications of HPIN in developing unique DNA polarity-based sensors.
除了经典的沃森-克里克（WC）连接的反平行链双链体（aps-DNA）外，DNA还能够形成生物活性平行链双链体（ps-DNA），其中两条参与的链具有相同的5'-3'极性。由于ps-DNA和aps-DNA具有相似的双链拓扑结构，以理想的选择性区分它们更具挑战性。在此，我们设计了一种独特的HPIN探针，用于荧光识别ps-DNA，但与aps-DNA结合时几乎没有荧光响应。霍格施泰因氢键模式在点亮HPIN荧光方面比反向沃森-克里克（rWC）模式更成功，这表明HPIN在对链极性决定的碱基配对特性进行结构适应性识别中起关键作用。开启荧光应源于适应性霍格施泰因碱基对结合后HPIN顺式/反式异构化的受限。这种针对aps-DNA识别ps-DNA的高性能证明了HPIN在开发独特的基于DNA极性的传感器方面的广阔应用前景。
