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Molecular Design for Reversing the Photoswitching Mode of Turning ON and OFF DNA Hybridization
Author(s) -
Liang Xingguo,
Takenaka Nobutaka,
Nishioka Hidenori,
Asanuma Hiroyuki
Publication year - 2008
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200700384
Subject(s) - photoswitch , azobenzene , isomerization , chemistry , photochemistry , oligonucleotide , molecular switch , duplex (building) , dna , substituent , fluorophore , stereochemistry , organic chemistry , molecule , optics , biochemistry , fluorescence , physics , catalysis
A new photoswitch for DNA hybridization involving para ‐substituted azobenzenes (such as isopropyl‐ or tert ‐butyl‐substituted derivatives) with L ‐threoninol as a linker was synthesized. Irradiation of the modified DNA with visible light led to dissociation of the duplex owing to the destabilization effect of the bulky substituent on the trans ‐azobenzene. In contrast, trans ‐to‐ cis isomerization (UV light irradiation) facilitated duplex formation. The direction of this photoswitching mode was entirely reversed relative to the previous system with an unmodified azobenzene on D ‐threoninol whose trans form turned on the hybridization, and cis form turned it off. Such reversed and reversible photoswitching of DNA hybridization was directly demonstrated by using fluorophore‐ and quencher‐attached oligonucleotides. Furthermore, it was revealed that the cis ‐to‐ trans thermal isomerization was greatly suppressed in the presence of the complementary strand owing to the formation of the more‐stable duplex in the cis form.