Inhibition of the In Vitro Replication of DNA by an Aptamer–Protein Complex in an Autonomous DNA Machine

DNA replication plays a central role in living organisms. Unregulated or uncontrollable DNA replication is well known to result in many pathological states, such as cancer, autoimmune diseases, and viral/bacterial infections. We report that an aptamer-protein complex could indirectly inhibit in vitro replication of DNA. An isothermal DNA machine based on the strand-displacement amplification is employed to support our assumption. An antithrombin aptamer sequence is rationally encoded into the DNA replication template. Once thrombin binds to the template, the as-formed aptamer-protein complexes can, in turn, become a barrier to the polymerase and inhibit the DNA replication activities in both static and dynamic modes. The inhibition is successfully confirmed by both fluorescence and gel-electrophoresis experiments. Considering the availability of a broad library of aptamers and the existence of various DNA/protein interactions, our results imply the possibility for the rational regulation of DNA replication in vivo.