Allosteric Control of Peroxidase-Mimicking DNAzyme Activity with Cationic Copolymers

Control of protein conformation and function, induced by the binding of an effector, plays significant roles in modulating biochemical reaction. Although the DNAzymes catalytic activity is similar to protein-based enzymes, reports of allosterically controlled DNAzymes are still limited except for aptamer-DNAzymes hybrrids. Here, we report allosteric control of peroxidase-mimicking DNAzyme activity using cationic copolymers. The DNAzyme requires a structured G-quadruplex core and hemin for activity, and the DNAzyme with a parallel G-quadruplex core has higher DNAzyme activity than DNAzymes based on other types of structure. We previously reported that a cationic copolymer composed of a cationic backbone and hydrophilic dextran side chains selectively stabilizes parallel G-quadruplex structures. In this study, we investigated effects of the cationic copolymer on peroxidase-mimicking DNAzyme activity. The cationic copolymer enhanced the DNAzyme activity by more than 30-fold by stabilizing the parallel G-quadruplex structure. Furthermore, reversible allosteric control of DNAzyme activity was achieved by adding cationic and anionic polymers.