Molecular recognition of tak-285 and lapatinib by inactive, active, and middle active-inactive HER2

Area of Science:

• Molecular Biology
• Structural Biology
• Pharmacology

Background:

• Epidermal Growth Factor Receptor (EGFR) inactive-to-active conformational shifts are understood through tyrosine kinase inhibitor (TKI) binding.
• HER2 (Human Epidermal growth factor Receptor 2) has an intermediate conformation co-crystallized with tak-285, but its binding selectivity remains unclear.
• Lack of structural data for HER2 limits understanding of TKI binding to specific receptor states.

Purpose of the Study:

• To elucidate the binding mechanisms of tak-285 to HER2.
• To determine the binding affinity of tak-285 and lapatinib to different HER2 conformations (active, inactive, intermediate).

Main Methods:

• Microsecond Molecular Dynamics (MD) simulations to obtain the active HER2 conformation.
• Molecular docking and MD simulations combined with the MMGBSA (Molecular Mechanics with Generalized Born Surface Area) approach.
• Assessment of binding affinity for tak-285 and lapatinib to HER2 conformers.

Main Results:

• Tak-285 exhibits higher binding affinity to both active and intermediate active-inactive HER2 conformations than lapatinib.
• Computational findings correlate with experimental data showing increased activity of tak-285 over lapatinib in breast cancer cell lines.

Conclusions:

• Tak-285 selectively binds to active and intermediate HER2 states with greater affinity.
• The study provides structural and energetic insights into tak-285's enhanced efficacy against HER2-expressing breast cancer.