Regulation of DNAzyme function by hypoxic irradiation that induces one-electron reduction of 2-oxoalkyl group on thymine base

We characterized the one-electron reduction of oligodeoxynucleotides with a 2-oxopropyl group on a thymine base ( dᵒˣᵒT ) and applied the reaction to the radiolytic activation of DNAzyme function. We designed a system in which the DNAzyme function of cleaving mRNA was suppressed by introduction of dᵒˣᵒT into the strand of DNAzyme. Hypoxic X-irradiation led to recovery of the cleavage ability because the 2-oxopropyl group was removed to form unmodified DNAzyme. We characterized the DNAzyme function by monitoring the fluorescence change of fluorophore- and quencher-labeled target strands. We confirmed that the DNAzyme function could be regulated by hypoxic X-irradiation and the reaction of dᵒˣᵒT .