Deacetylation-activated construction of single quantum dot-based nanosensor for sirtuin 1 assay

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Sirtuin 1 (SIRT1) is a key histone deacetylase regulating crucial biological processes.
• Dysregulation of SIRT1 is implicated in diseases like cancer, diabetes, and aging.
• Accurate detection of SIRT1 activity is vital for therapeutic development.

Purpose of the Study:

• To develop a deacetylation-activated single quantum dot (QD)-based nanosensor for sensitive SIRT1 activity detection.
• To establish a platform for enzyme kinetics measurement and SIRT1 inhibitor screening.
• To enable detection of SIRT1 activity in cancer cells for epigenetic research.

Main Methods:

• Constructed a nanosensor using a Cy5-labeled peptide substrate and a streptavidin-coated QD.
• Utilized SIRT1's deacetylase activity to trigger peptide biotinylation and QD-peptide assembly via FRET.
• Employed total internal reflection fluorescence-based single-molecule detection for quantification.

Main Results:

• Achieved a highly sensitive SIRT1 detection limit as low as 3.91 pM.
• Demonstrated the nanosensor's capability for enzyme kinetic parameter measurement.
• Successfully applied the nanosensor to detect SIRT1 activity in cancer cells.

Conclusions:

• The developed QD-based nanosensor offers a sensitive and robust method for SIRT1 activity assay.
• This platform facilitates SIRT1 inhibitor screening and drug discovery.
• The nanosensor provides a powerful tool for epigenetic research and understanding SIRT1's role in disease.