A Practical Approach to Quantitatively Assessing Equilibrium-Constant Accuracy from a Single Binding Isotherm

Area of Science:

• Chemical Thermodynamics
• Biophysical Chemistry
• Computational Chemistry

Background:

• Equilibrium constants are vital for chemical systems but often suffer from systematic inaccuracies despite high precision.
• Traditional nonlinear regression methods for determining equilibrium constants lack practical accuracy assessment tools for molecular scientists.

Purpose of the Study:

• To develop a practical and accessible method for quantitatively assessing the accuracy of computed equilibrium constants.
• To provide researchers with a reliable measure of accuracy beyond mere precision.

Main Methods:

• Integration of error-propagation and regression-stability analyses.
• Development of a workflow to determine the accuracy confidence interval (ACI) for equilibrium dissociation constants (Kd).
• Implementation of a user-friendly web application for ACI calculation.

Main Results:

• A novel workflow for calculating the ACI of equilibrium constants, specifically Kd values from binding isotherms.
• Demonstration of the workflow's utility through three case studies.
• Availability of a web tool (https://aci.sci.yorku.ca) for widespread adoption.

Conclusions:

• The ACI provides a crucial measure for the accuracy of nonlinear regression parameters, complementing precision.
• This method empowers molecular scientists to avoid misconceptions arising from relying solely on precise but inaccurate data.
• The developed workflow and web application facilitate the routine assessment of equilibrium constant accuracy in research.