Metalloregulation of Triple Helix Formation by Control of the Loop Conformation |
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Authors: | Toshihiro Ihara Yoshinobu Sato Hiroshi Shimada Akinori Jyo |
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Affiliation: | 1. Department of Applied Chemistry and Biochemistry , Graduate School of Science and Technology, Kumamoto University , Kumamoto , Japan;2. PRESTO , Japan Science and Technology Agency , Saitama , Japan;3. Department of Applied Chemistry and Biochemistry , Graduate School of Science and Technology, Kumamoto University , Kumamoto , Japan |
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Abstract: | The flexible polypyridine ligand, 2,2′:6′,2″-terpyridine (terpy), was built into the backbone of oligonucleotides to form DNA conjugates. The terpy unit functioned as a good loop when the conjugates formed the bimolecular triplexes with complementary oligopurine. The triplex structure was destabilized by the specific interaction with divalent transition metal ions (Cu2+, Zn2+, and Fe2+), in particular Cu2+ ions. This ion destabilized one of the triplexes by 4.2 kcalmol?1 or made the triplex formation constant less than 1/103 at 298 K. This result is attributed to the substantial turbulence of the terminal structure of the triplexes. |
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Keywords: | DNA triplex terpyridine metal ion UV melting amidite reagent |
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