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Updated: May 16, 2025

A Semi-High-Throughput Adaptation of the NADH-Coupled ATPase Assay for Screening Small Molecule Inhibitors
Published on: August 17, 2019
Methods for kinetic evaluation of reversible covalent inhibitors from time-dependent IC50 data
Lavleen K Mader1, Jeffrey W Keillor1
1Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa Ontario K1N 6N5 Canada jkeillor@uottawa.ca.
New methods quantify time-dependent inhibition kinetics for reversible covalent drugs. These tools help accurately rank drug candidates by analyzing incubation time-dependent IC50 data for better drug development.
Area of Science:
- Pharmacology
- Biochemistry
- Drug Discovery
Background:
- Reversible covalent inhibitors exhibit time-dependent inhibition due to slow equilibrium.
- Current methods using IC50 values lack the ability to determine key kinetic constants.
Purpose of the Study:
- To develop methods for analyzing time-dependent IC50 data.
- To determine inhibition (Ki, k-i) and covalent modification (k5, k6) constants for reversible covalent inhibitors.
Main Methods:
- An implicit equation to estimate kinetic constants from time-dependent IC50 values.
- A numerical modeling method, EPIC-CoRe, for fitting kinetic parameters.
Main Results:
- The developed methods successfully estimated kinetic constants for saxagliptin.
- Results were consistent with established methodologies, validating the new approaches.
Conclusions:
- Introduced practical methods for evaluating time-dependent reversible covalent inhibitors.
- Enables rigorous characterization for optimizing drug binding and reactivity.
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