IC50
Definition
IC50 (half maximal inhibitory concentration) is a quantitative measure indicating the concentration of an inhibitor required to reduce a biological or biochemical function by 50%. It is the most widely used metric in pharmacology to assess drug potency and efficacy. IC50 values are determined through dose-response experiments where increasing concentrations of a compound are tested against a specific target (enzyme, receptor, or cellular process). Lower IC50 values indicate higher potency, meaning less drug is needed to achieve the desired inhibitory effect. IC50 is crucial for comparing compounds during drug discovery, understanding structure-activity relationships, and predicting therapeutic windows. However, IC50 values are context-dependent and can vary based on experimental conditions, assay type, and substrate concentrations.
Visualize IC50 in Nodes Bio
Researchers can visualize IC50 data across drug-target networks to identify selectivity patterns and off-target effects. By mapping IC50 values onto protein interaction networks, users can explore how compound potency correlates with pathway position, identify polypharmacology opportunities, and compare inhibitor profiles across related targets. Network visualization helps reveal structure-activity relationships by connecting chemical scaffolds to their target inhibition profiles.
Visualization Ideas:
- Drug-target interaction networks colored by IC50 values to show selectivity profiles
- Kinase phylogenetic trees annotated with compound IC50 data across the kinome
- Pathway maps showing IC50 gradients across protein complexes and signaling cascades
Example Use Case
A pharmaceutical team developing kinase inhibitors for cancer therapy measures IC50 values against a panel of 50 kinases. They discover their lead compound has an IC50 of 5 nM against the primary target (EGFR) but also shows sub-micromolar IC50 values against three off-targets. Using network analysis, they map these interactions onto the human kinome tree and signaling pathways to assess whether the off-target activity might cause toxicity or provide beneficial polypharmacology, ultimately guiding medicinal chemistry optimization efforts.