Reduction-Responsive DNA Duplex Containing O6-Nitrobenzyl-Guanine

Stimuli-controlled structural transitions of nucleic acids have received growing attentions owing to their potential applications in the fields of chemical and synthetic biology. Here, we describe the development of reduction-responsive deoxyribonucleic acid (DNA) duplexes, in which guanine rings bearing a reduction-responsive cleavable nitrobenzyl (NB) group at the O 6 position (G NB ) are introduced at defined positions. We demonstrate that the artificial NB group can be removed in response to reduction stimulus without the dissociation of the intermolecular duplex structure, which comprises a G-quadruplex forming nucleic acid strand with one G NB and its complementary sequence with one mismatch pair. Meanwhile, another duplex that comprised a G-quadruplex forming nucleic acid strand with two G NB and its complementary sequence with three mismatch pairs exhibited reduction-responsive structural transitions from intermolecular duplex to intramolecular quadruplex. These findings might be useful for the development of DNA architectures endowed with reduction-responsive functions.