Related Experiment Video
Updated: May 10, 2026

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
Published on: October 27, 2020
Computational studies of TGF-βRI (ALK-5) inhibitors: analysis of the binding interactions between ligand-receptor
Sheila C Araujo1, Vinicius G Maltarollo, Kathia M Honorio
1Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, R. Santa Adélia 166, 09210-170 Santo André, SP, Brazil.
Abstract:
ALK-5 (Activin-Like Kinase 5) is a biological receptor involved in a variety of pathological processes such as cancer and fibrosis. ALK-5 receptor propagates an intracellular signaling that forms a protein complex capable of reaching the nucleus and modulating the gene transcription. In the present study, comparative molecular field analysis (CoMFA) and hologram quantitative structure-activity relationship (HQSAR) studies were conducted on a series of potent ALK-5 inhibitors. Significant correlation coefficients (CoMFA, r(2)=0.99 and q(2)=0.85; HQSAR, r(2)=0.92 and q(2)=0.72) were obtained, indicating the predictive potential of the 2D and 3D models for untested compounds. The models were then used to predict the potency of a test set, and the predicted values from the HQSAR and CoMFA models were in good agreement with the experimental results. The final QSAR models, along with the information obtained from 3D (steric and electrostatic) contour maps and 2D contribution maps, can be useful for the design of novel bioactive ligands.
Insights
This study developed predictive models for Activin-Like Kinase 5 (ALK-5) inhibitors using CoMFA and HQSAR. These models accurately predict the potency of new ALK-5 inhibitors, aiding in drug design.
Area of Science:
- Medicinal Chemistry
- Computational Biology
- Molecular Pharmacology
Background:
- Activin-Like Kinase 5 (ALK-5) is a key receptor in pathological processes like cancer and fibrosis.
- ALK-5 signaling influences gene transcription through nuclear protein complexes.
- Developing potent and selective ALK-5 inhibitors is crucial for therapeutic intervention.
Purpose of the Study:
- To develop and validate quantitative structure-activity relationship (QSAR) models for ALK-5 inhibitors.
- To utilize CoMFA and HQSAR methods for predicting inhibitor potency.
- To guide the rational design of novel ALK-5 targeting ligands.
Main Methods:
- Comparative Molecular Field Analysis (CoMFA) was applied to a series of ALK-5 inhibitors.
- Hologram Quantitative Structure-Activity Relationship (HQSAR) was employed for 2D-based modeling.
- Statistical validation of models using correlation coefficients (r^2 and q^2) and prediction on a test set.
Main Results:
- High statistical significance was achieved for both CoMFA (r^2=0.99, q^2=0.85) and HQSAR (r^2=0.92, q^2=0.72) models.
- The developed QSAR models demonstrated strong predictive ability for unseen ALK-5 inhibitor compounds.
- Predicted potencies from both models showed good agreement with experimental data.
Conclusions:
- Validated 2D and 3D QSAR models provide a reliable framework for ALK-5 inhibitor discovery.
- 3D contour maps and 2D contribution maps offer insights into structure-activity relationships.
- These findings facilitate the design of novel, potent, and effective ALK-5 inhibitors for therapeutic applications.
Related Concept Videos
TGF - β Signaling Pathway
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-protein Interfaces
The Equilibrium Binding Constant and Binding Strength
