title: Reversible photoswitching of RNA hybridization at room temperature with an azobenzene C-nucleoside.
abstract: Photoregulation of RNA remains a challenging task as the introduction of a photoswitch entails changes in the shape and the stability of the duplex that strongly depend on the chosen linker strategy. Herein, the influence of a novel nucleosidic linker moiety on the photoregulation efficiency of azobenzene is investigated. To this purpose, two azobenzene C-nucleosides were stereoselectively synthesized, characterized, and incorporated into RNA oligonucleotides. Spectroscopic characterization revealed a reversible and fast switching process, even at 20 °C, and a high thermal stability of the respective cis isomers. The photoregulation efficiency of RNA duplexes upon trans-to-cis isomerization was investigated by using melting point studies and compared with the known D-threoninol-based azobenzene system, revealing a photoswitching amplitude of the new residues exceeding 90 % even at room temperature. Structural changes in the duplexes upon photoisomerization were investigated by using MM/MD calculations. The excellent photoswitching performance at room temperature and the high thermal stability make these new azobenzene residues promising candidates for in-vivo and nanoarchitecture photoregulation applications of RNA.
authors.affiliation: Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt am Main, Max-von-Laue-Str. 9, 60438 Frankfurt/Main (Germany), Fax: (+49) 69-798-763-42505.
authors.forename: Thomas
authors.initials: T
authors.lastname: Goldau
authors.forename: Keiji
authors.initials: K
authors.lastname: Murayama
authors.forename: Clara
authors.initials: C
authors.lastname: Brieke
authors.forename: Sabrina
authors.initials: S
authors.lastname: Steinwand
authors.forename: Padmabati
authors.initials: P
authors.lastname: Mondal
authors.forename: Mithun
authors.initials: M
authors.lastname: Biswas
authors.forename: Irene
authors.initials: I
authors.lastname: Burghardt
authors.forename: Josef
authors.initials: J
authors.lastname: Wachtveitl
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Asanuma
authors.forename: Alexander
authors.initials: A
authors.lastname: Heckel
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D006824:Hybridization, Genetic; D015394:Molecular Structure; D009705:Nucleosides / Q000737:chemistry*; D009841:Oligonucleotides; D012313:RNA / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D009705:Nucleosides; D009841:Oligonucleotides; D012313:RNA; C009850:azobenzene
keywords: RNA; azobenzenes; nucleic acids; photoisomerization; photoswitches