Pharmacophore Modeling, Docking and Molecular Dynamics Studies on Caspase-3 Activators Binding at β-Tubulin Site

Area of Science:

• Medicinal Chemistry
• Computational Chemistry
• Molecular Biology

Background:

• Caspase 3 activation is crucial for inducing apoptosis and represents a significant target for anticancer drug development.
• Understanding the structural requirements for caspase 3 activation is essential for designing effective therapeutic agents.

Purpose of the Study:

• To investigate the essential structural features required for caspase 3 activation using computational methods.
• To develop a pharmacophore model for caspase 3 activators based on the drug candidate Azixa and its analogs.

Main Methods:

• Utilized a dataset of 76 caspase 3 activator compounds, including Azixa, for pharmacophore model generation.
• Employed Discovery Studio 2.0 for quantitative structure-activity relationship (QSAR) analysis and pharmacophore modeling.
• Performed molecular docking and dynamics simulations to propose a binding mode of Azixa at the beta-tubulin site.

Main Results:

• The best pharmacophore model (Hypo1) comprised two hydrophobic aliphatic (Hal), two hydrophobic aromatic (Har), and one hydrogen bond acceptor (HBA) features.
• This model demonstrated a high correlation coefficient (0.85) and accurately predicted the activity of a test set (Rpred = 0.8).
• Azixa's caspase 3 activation mechanism involves binding to the beta-tubulin site, similar to colchicine.

Conclusions:

• The identified pharmacophore features are critical for designing novel caspase 3 activators.
• The proposed binding mode of Azixa at the beta-tubulin site provides insights into its mechanism of action.
• This research facilitates the development of new anticancer drugs targeting caspase 3 activation.