Dual Crosslinking Photo-Switches for Orthogonal Photo-Control of Hybridization Between Serinol Nucleic Acid and RNA

Wavelength-selective photo-regulation by multiple chromophores responding to different wavelengths can expand the variation of photo-manipulating systems. Herein, we report the orthogonal photo-regulation of duplex formation between serinol nucleic acid (SNA) and RNA using light-induced crosslinking reactions mediated by a new photo-reactive nucleobase 8-naphthylvinyladenine (^NVA) and previously described 8-pyrenylvinyladenine (^PVA). An intrastrand crosslink was induced in an SNA strand containing two adjacent ^NVA residues by irradiation with 340–405 nm light; the crosslink was reversed by irradiation with ≤300 nm light. In an SNA strand with adjacent ^NVA and ^PVA residues, an intrastrand crosslink resulted from irradiation with 405–465 nm light that was reversed by irradiation with ≤340 nm light. Intrastrand photo-crosslinking caused severe destabilization of an SNA/RNA duplex, resulting in dissociation to single strands. Cycloreversion resulted in duplex formation. With these ^NVA/^NVA and ^NVA/^PVA photo-switches, four hybridization states of two SNA/RNA duplexes could be orthogonally photo-controlled by irradiation with a suitable wavelength of light.