Clear-cut photo-regulation of the formation and dissociation of the DNA duplex by modified oligonucleotide involving multiple azobenzenes

Abstract

Multiple azobenzenes were introduced into the oligonucleotide on D-threoninol for the clear-cut photo-regulation of the formation and dissociation of DNA duplex. When azobenzenes took trans form, introduction of multiple azobenzenes (azobenzenes:nucleobases = 1:2) did not interfere with duplex formation at all compared with their native duplex. In contrast, melting temperature (Tm) uniformly decreased with the number of azobenzenes when they took cis-form. As a result, clear-cut photo-regulation of the duplex formation was attained under physiological conditions. Furthermore, nearest-neighbor parameters for these azobenzene-tethered oligonucleotides were obtained. It was found that Tms estimated from these parameters well coincided with those of measured ones.