A Non‐G‐Quadruplex Hemin Aptamer Forms a Better Peroxidase Mimicking DNAzyme

作者：Claudia Rodríguez-Almazán, Yunus A. Kaiyum, Philip E. Johnson, Juewen Liu · 发表于：ChemBioChem · 年份：2025 · DOI：10.1002/cbic.202500486 · 被引用次数：2 · 研究领域：Advanced biosensing and bioanalysis techniques、DNA and Nucleic Acid Chemistry、RNA Interference and Gene Delivery

G‐quadruplex DNA is known to bind to hemin, forming a complex that exhibits peroxidase‐like activity. A non‐G‐quadruplex aptamer named Hem1‐2T also exhibits horseradish peroxidase (HRP) like activity upon binding to hemin. Herein, the catalytic characteristics of the Hem1‐2T aptamer are studied and compared with PS2.M, an extensively studied G‐quadruplex. From pH 6–8, the activity of Hem1‐2T decreases with the increase in pH, which is similar to HRP, whereas the activity of PS2.M increases with pH, suggesting that Hem1‐2T might be a better mechanistic mimic of HRP. Additionally, Hem1‐2T is more effective at protecting hemin from degradation by H 2 O 2 , as evidenced by a slower decrease in the absorbance at 404 nm compared to PS2.M and more sustained catalysis. NMR spectroscopy indicates that hemin promotes ligand‐induced structure formation in the Hem1‐2T aptamer and forms a specific complex, whereas hemin interacts with the PS2.M G‐quadruplex in a way leading to the disappearance of NMR peaks. Overall, the Hem1‐2T‐hemin complex is a better and more stable HRP mimic, supporting its potential applications in bioanalysis and biocatalysis.