An oxidatively damaged G-quadruplex/hemin DNAzyme.

Oxidative damage of guanine to 8-oxoguanine triggers a partial and variable loss of G-quadruplex/hemin DNAzyme activity and provides clues to the mechanistic origins of DNAzyme deactivation, which originates from an interplay between decreased G-quadruplex stability, lower hemin affinity and a modification of the nature of hemin binding sites.