A heme•DNAzyme activated by hydrogen peroxide catalytically oxidizes thioethers by direct oxygen atom transfer rather than by a Compound I-like intermediate.

ABSTRACT: Hemin [Fe(III)-protoporphyrin IX] is known to bind tightly to single-stranded DNA and RNA molecules that fold into G-quadruplexes (GQ). Such complexes are strongly activated for oxidative catalysis. These heme•DNAzymes and ribozymes have found broad utility in bioanalytical and medicinal chemistry and have also been shown to occur within living cells. However, how a GQ is able to activate hemin is poorly understood. Herein, we report fast kinetic measurements (using stopped-flow UV-vis spectrophotometry) to identify the H2O2-generated activated heme species within a heme•DNAzyme that is active for the oxidation of a thioether substrate, dibenzothiophene (DBT). Singular value decomposition and global fitting analysis was used to analyze the kinetic data, with the results being consistent wi

SUBMITTER: Shumayrikh NM 

PROVIDER: S-EPMC7913675 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature