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Updated: Sep 23, 2025

A G-quadruplex DNA-affinity Approach for Purification of Enzymatically Active G4 Resolvase1
Published on: March 18, 2017
Inactivation Kinetics of G-Quadruplex/Hemin Complex and Optimization for More Reliable Catalysis
Anthony R Monte Carlo1, Jinglin Fu2,3
1Department of Biology, Rutgers University - Camden, 201 South Broadway, Camden, NJ 08103, USA.
Abstract:
Reliable catalysis is critical for the synthesis of various chemicals, molecular sensing and biomedicine. G-quadruplex/Hemin (GQH) complex, a peroxidase-mimicking DNAzyme, has been widely used in various publications. However, a concern exists about the unstable kinetics of GQH-catalyzed peroxidation. This work investigates several factors that result in the inactivation of GQH and the signal degradation during long reaction periods, including pH, buffer component, the selection of substrate and the oxidation damage of cofactor. Using colorimetric and fluorescent assays, GQH was found to be highly unstable under basic conditions with 50 % of GQH activity lost within 2 minutes at high H2 O2 concentrations. Appropriate conditions and substrates are suggested for accurately characterizing GQH-catalyzed reactions, as well as optimization to improve the catalytic reliability, such as the use of polyhistidine and cascade reactions. These results could be useful for GQH-related applications.
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