Assessment of DNase Activity by Ratiometric Fluorescence Resonance Energy Transfer

Area of Science:

• Biochemistry
• Molecular Biology
• Enzyme Assays

Background:

• Deoxyribonuclease (DNase) activity is crucial in various biological processes and disease states.
• Accurate quantification of DNase activity is essential for understanding enzyme kinetics and inhibitor effects.
• Existing methods may lack sensitivity or real-time monitoring capabilities for subtle DNA cleavage events.

Purpose of the Study:

• To develop a simple, sensitive, and ratiometric Förster resonance energy transfer (FRET) assay for DNase activity.
• To enable real-time detection and quantitative assessment of single-stranded DNA breaks.
• To investigate the impact of reaction conditions (pH, temperature, buffer) on DNase activity.

Main Methods:

• Utilized a staple-shaped, dual-tagged 38-mer FRET oligoprobe as a DNA cleavage sensor.
• Employed ratiometric FRET measurements based on donor and acceptor emission signal ratios.
• Applied the assay to assess DNase activity influenced by varying reaction parameters.

Main Results:

• The ratiometric FRET assay demonstrated high sensitivity for detecting single-stranded DNA breaks.
• The assay effectively quantified DNase activity under different pH, temperature, and buffer conditions.
• Successfully applied to detect and analyze the DNase activity of leukocyte elastase inhibitor (LEI).

Conclusions:

• The developed ratiometric FRET assay is a robust tool for sensitive DNase activity detection and quantification.
• The assay is particularly advantageous for studying weak nucleolytic activities and pH-dependent enzyme behavior.
• This method provides a valuable approach for evaluating enzyme inhibitors and optimizing reaction conditions for DNase assays.