Evaluation of DNA adduct damage using G-quadruplex-based DNAzyme

Area of Science:

• Biochemistry
• Toxicology
• Analytical Chemistry

Background:

• Toxicity assessment of pharmaceutical candidates and industrial chemicals is crucial for safety evaluation.
• Current analytical methods for DNA adduct analysis are limited, hindering comprehensive safety assessments.
• Developing practical methods for DNA adduct detection is essential for understanding chemical toxicity.

Purpose of the Study:

• To develop a novel DNAzyme-based method for detecting DNA adduct damage.
• To utilize this method for the toxicity assessment of drugs and industrial chemicals.
• To enhance the safety evaluation process by providing a practical analytical tool.

Main Methods:

• Screening of 18 structural variants of G4 DNAzyme to identify a suitable candidate.
• Utilizing the EA2 DNAzyme, which shows structural instability and sensitivity to DNA damaging agents.
• Monitoring the reduction in peroxidase activity of the G4 DNAzyme caused by DNA adduct formation.

Main Results:

• The EA2 DNAzyme was identified as sensitive to styrene oxide (SO) DNA damage.
• Covalent binding of SO to the DNAzyme disrupts G4 quadruplex formation by affecting Hoogsteen hydrogen bonding.
• Reduced peroxidase activity of the DNAzyme serves as an indicator of DNA adduct damage.

Conclusions:

• The developed DNAzyme-based method provides a practical approach for DNA adduct analysis.
• This method enables genotoxic assessment of pharmaceutical candidates and industrial chemicals.
• The approach can elucidate toxicity pathways, predict toxic effects, and evaluate human health risks.