A model-informed method to retrieve intrinsic from apparent cooperativity and project cellular target occupancy for...

Area of Science:

• Biochemistry
• Pharmacology
• Computational Chemistry

Background:

• Therapeutics targeting challenging proteins often involve ternary complex formation.
• Understanding compound cooperativity is crucial for optimizing drug discovery and selectivity.
• Intrinsic cooperativity (α) quantifies affinity changes in pre-bound states.

Purpose of the Study:

• To present a mathematical modeling methodology for estimating intrinsic cooperativity (α) from apparent cooperativities.
• To extend the model from biochemical to cellular assays.
• To translate biochemical potency into cellular target occupancy for mechanism validation.

Main Methods:

• Developed a mathematical model to estimate intrinsic cooperativity (α) using binary binding affinities and protein concentrations.
• Extended the model to account for open systems in cellular assays (ligand concentrations).
• Applied the model to predict cellular target occupancy from biochemical potency.

Main Results:

• The methodology accurately estimates intrinsic cooperativity (α) from experimental data.
• The model successfully translates biochemical findings to cellular contexts.
• The approach enables prediction of cellular target occupancy for mechanism of action studies.

Conclusions:

• The presented mathematical model provides a robust method for quantifying intrinsic cooperativity (α) in ternary complex-forming compounds.
• This approach is valuable for early-stage drug discovery, enhancing target selectivity and mechanism validation.
• The model facilitates the translation of in vitro potency to in vivo cellular responses.