Zippered G-quadruplex/hemin DNAzyme: exceptional catalyst for universal bioanalytical applications

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• G-quadruplex (G4)/hemin DNAzymes are promising horseradish peroxidase (HRP)-mimics.
• Their catalytic capacity is limited for broader applications.

Purpose of the Study:

• To develop an enhanced HRP mimic using a proximity-enhanced cofactor assembly strategy (PECA).
• To improve catalytic efficiency and explore applications in diagnostics.

Main Methods:

• Implemented PECA to create zippered G4/hemin DNAzyme (Z-G4/H) by hybridizing DNA-grafted hemin (DGH) with complementary G4 sequences (cG4s).
• Investigated catalytic efficiency, mechanism, and environmental tolerance of Z-G4/H compared to classical G4/hemin DNAzymes (C-G4/H).
• Developed a proximity recognition transducer based on PECA for detecting gene rearrangement and HER2 dimerization.

Main Results:

• Z-G4/H exhibited significantly higher activity, faster catalytic rates, and greater environmental tolerance than C-G4/H.
• The PECA strategy effectively mimics protease cofactor-apoenzyme interactions.
• Demonstrated sensitive detection of gene rearrangement and imaging of HER2 dimerization.

Conclusions:

• Z-G4/H represents a highly efficient HRP mimic with broad potential in clinical diagnostics and biomolecule interaction research.
• The PECA strategy offers a novel approach for engineering high-performance mimic enzymes.
• This work inspires the development of protease-free mimic enzymes.