A method for deciding whether two experimental fluorescence anisotropy decay curves are significantly different

Area of Science:

• Biophysics
• Biochemistry
• Physical Chemistry

Background:

• Time-resolved fluorescence anisotropy decay measurements are crucial for studying molecular dynamics and interactions.
• Analyzing differences between decay curves can reveal subtle changes induced by effectors.
• Existing methods may lack the precision to accurately quantify these differences.

Purpose of the Study:

• To develop and validate a robust method for comparing fluorescence anisotropy decay curves.
• To provide a quantitative assessment of the significance of differences between decay curves.
• To improve the analysis of time-resolved depolarization experiments.

Main Methods:

• Numerical deconvolution of fluorescence anisotropy decay curves using a non-a priori approach.
• Calculation of the difference (D) between deconvoluted decay curves.
• Computation of variance for each point in D and definition of a confidence interval to assess significance.

Main Results:

• The method allows for direct identification of the time range where fluorescence anisotropy changes occur.
• The significance of differences between decay curves can be statistically determined.
• The approach was successfully tested on 3-phosphoglycerate kinase in the presence and absence of ATP and 3-phosphoglycerate.

Conclusions:

• The described method offers a significant advancement for time-resolved depolarization experiments.
• It provides a reliable way to compare fluorescence anisotropy decay curves and detect effector-induced perturbations.
• This technique enhances the quantitative analysis of molecular dynamics in biological systems.