Bipyridine-Modified DNA Three-Way Junctions with Amide linkers: Metal-Dependent Structure Induction and Self-Sorting |
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Authors: | Dr Yusuke Takezawa Shiori Sakakibara Prof Dr Mitsuhiko Shionoya |
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Institution: | Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan |
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Abstract: | DNA three-way junction (3WJ) structures are essential building blocks for the construction of DNA nanoarchitectures. We have synthesized a bipyridine (bpy)-modified DNA 3WJ by using a newly designed bpy-modified nucleoside, Ubpy- 3 , in which a bpy ligand is tethered via a stable amide linker. The thermal stability of the bpy-modified 3WJ was greatly enhanced by the formation of an interstrand NiII(bpy)3 complex at the junction core (ΔTm=+17.7 °C). Although the stereochemistry of the modification site differs from that of the previously reported bpy-modified nucleoside Ubpy- 2 , the degree of the NiII-mediated stabilization observed with Ubpy- 3 was comparable to that of Ubpy- 2 . Structure induction of the 3WJs and the duplexes was carried out by the addition or removal of NiII ions. Furthermore, NiII-mediated self-sorting of 3WJs was performed by using the bpy-modified strands and their unmodified counterparts. Both transformations were driven by the formation of NiII(bpy)3 complexes. The structural induction and self-sorting of bpy-modified 3WJs are expected to have many potential applications in the development of metal-responsive DNA materials. |
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Keywords: | bioinorganic chemistry DNA structures DNA three-way junctions metal coordination switching |
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