Department of Biology, Rutgers University - Camden, 201 South Broadway, Camden, NJ 08103, USA.
Department of Chemistry, Rutgers University-Camden, 201 South Broadway, Camden, NJ 08103, USA.
Chempluschem. 2022 Jul;87(7):e202200090. doi: 10.1002/cplu.202200090. Epub 2022 May 11.
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 H O 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.
可靠的催化对于各种化学物质的合成、分子传感和生物医药至关重要。G-四链体/血红素（GQH）复合物作为一种过氧化物酶模拟 DNA 酶，已被广泛应用于各种文献中。然而，人们担心 GQH 催化的过氧化物酶反应动力学不稳定。本工作研究了导致 GQH 失活和信号降解的几个因素，包括 pH 值、缓冲成分、底物选择和辅因子氧化损伤。通过比色法和荧光法测定，发现 GQH 在碱性条件下极不稳定，在高 H2O2 浓度下，2 分钟内 GQH 活性丧失 50%。建议选择合适的条件和底物来准确表征 GQH 催化反应，并进行优化以提高催化可靠性，例如使用组氨酸多聚体和级联反应。这些结果对于 GQH 相关应用可能是有用的。
