A new assay method for DNase by fluorescence polarization and fluorescence intensity using DNA-ethidium bromide...

Area of Science:

• Biochemistry
• Enzymology
• Molecular Biology

Background:

• Deoxyribonuclease (DNase) enzymes play critical roles in DNA metabolism and cellular processes.
• Accurate quantification of DNase activity is essential for various biological and diagnostic applications.
• Existing methods for DNase activity determination can be complex or lack sensitivity.

Purpose of the Study:

• To develop and validate a novel fluorescence polarization (FP) assay for the sensitive and quantitative determination of DNase activity.
• To establish the applicability of the FP assay for enzyme kinetics and qualitative analysis.
• To demonstrate the specificity and reliability of the FP assay using known DNase inhibitors and other enzymes.

Main Methods:

• Utilized ethidium bromide-labeled DNA as a substrate for DNase digestion.
• Measured changes in fluorescence polarization and intensity correlating with DNA degradation.
• Determined DNase activity quantitatively and assessed inhibition by specific compounds like EDTA.
• Evaluated assay specificity using various enzymes.

Main Results:

• The FP assay demonstrated a quantitative determination of DNase activity down to 0.1 ng/ml.
• A significant decrease in fluorescence polarization and intensity was observed upon DNase-mediated DNA cleavage.
• The DNase activity measured by FP was effectively inhibited by specific inhibitors (EDTA, pyrophosphate, thymidine-3',5'-diphosphate).
• The assay showed specificity for DNase compared to other enzymes.

Conclusions:

• The developed fluorescence polarization method offers a simple, rapid, and sensitive approach for DNase activity assessment.
• This assay is suitable for both quantitative and qualitative determination of DNase levels.
• The method is applicable for kinetic analysis of DNase enzymes and has potential diagnostic applications.