Photocontrol of DNA Duplex Formation by Using Azobenzene-Bearing Oligonucleotides

✍ Scribed by Hiroyuki Asanuma; Xingguo Liang; Takayuki Yoshida; Makoto Komiyama

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 187 KB
• Volume: 2
• Category: Article
• ISSN: 1439-4227
• DOI: 10.1002/1439-7633(20010105)2:1<39::aid-cbic39>3.0.co;2-e

✦ Synopsis

The duplex-forming activities of oligonucleotides can be photomodulated by incorporation of an azobenzene unit. Upon isomerizing the trans-azobenzene to the cis form by irradiation with UV light, the T m value of the duplex (with the complementary DNA) is lowered so that the duplex is dissociated. The duplex is formed again when the cis-azobenzene is converted to the transazobenzene by irradiation with visible light. The photoregulation is successful irrespective of the position of the azobenzene unit in the oligonucleotides. The trans-azobenzene in the oligonucleotides intercalates between two DNA base pairs in the duplexes and stabilizes them because of a favorable enthalpy change. The nonplanar structure of a cis-azobenzene is unfavorable for such an interaction. These photoresponsive oligonucleotides are promising candidates for the regulation of various bioreactions.