Synthesis and properties of a novel artificial nucleoside that acts as a redox switch.

Oligonucleotide that can reversibly alter the duplex-forming ability in response to an external factor has potential to be applied to various genome technologies, e.g. antisense and gene diagnosis technology. A novel bridged nucleoside which is capable of sensing an oxidant and reductant was designed and synthesized. The nucleoside formed a disulfide bridge between C2' and C4' positions, which would enhance its duplex-forming ability under oxidative conditions. Contrastingly, the disulfide bridge was cleaved under reductive conditions; it could cause decrease of duplex-forming ability.