Label-Free and Ultrasensitive APE1 Detection Based on Hybridization Chain Reaction Combined with G-Quadruplex.

Area of Science:

• Biochemistry
• Molecular Biology
• Genomics

Background:

• Apurinic/apyrimidinic endonuclease 1 (APE1) is crucial for DNA repair and maintaining genomic stability.
• Dysregulation of APE1 is implicated in various diseases, including cancer and cardiovascular disorders.
• Current APE1 detection methods lack the sensitivity required for certain applications.

Purpose of the Study:

• To develop an innovative biosensing platform for ultrasensitive detection of APE1.
• To enable enzyme- and label-free bioassays for APE1.
• To provide a tool for APE1 inhibitor screening and evaluation.

Main Methods:

• Integration of APE1-specific site recognition with hybridization chain reaction (HCR) signal amplification.
• Design of an AP site-containing hairpin (HP) probe cleaved by APE1.
• Release of an HCR initiator upon APE1-mediated cleavage to trigger signal amplification.

Main Results:

• Achieved ultrahigh sensitivity for APE1 detection with a limit of detection of 1.0 × 10^-8 U/mL.
• Demonstrated robust biosensor performance in complex biological matrices like cell lysates.
• Validated the platform's applicability for screening and evaluating APE1 inhibitors.

Conclusions:

• The developed biosensing platform offers a highly sensitive and efficient method for APE1 detection.
• This platform facilitates enzyme- and label-free bioassays, overcoming limitations of existing techniques.
• The biosensor is a valuable tool for disease research and therapeutic development targeting APE1.