Unveiling the biophysical basis of DYRK kinase family isoform selectivity mechanism of Abemaciclib using...

Area of Science:

• Biochemistry
• Structural Biology
• Pharmacology

Background:

• Dual-specificity tyrosine phosphorylation-regulated kinases (DYRKs) are vital for cell growth and neurodevelopment.
• DYRK dysregulation is implicated in Down syndrome and various cancers.
• Achieving selective inhibition of DYRK1A over highly similar isoforms is a major therapeutic challenge.

Purpose of the Study:

• To evaluate the isoform selectivity of Abemaciclib, an FDA-approved CDK4/6 inhibitor, against the DYRK kinase family.
• To elucidate the molecular basis for Abemaciclib's binding preferences within the DYRK family.
• To provide insights for designing novel, selective DYRK inhibitors.

Main Methods:

• Computational approaches including molecular docking and molecular dynamics simulations were utilized.
• The Molecular Mechanics Poisson-Boltzmann Surface Area (MM/PBSA) method was employed for binding energy calculations.
• Statistical analysis was performed to validate the computational findings.

Main Results:

• Abemaciclib demonstrated the strongest binding affinity for DYRK1B, followed by DYRK1A, DYRK4, DYRK3, and DYRK2.
• Enhanced selectivity for DYRK1B is attributed to superior van der Waals and electrostatic interactions.
• Specific amino acid residues, including Leu241, Phe170, Glu239, and His285, were identified as critical for differential binding.

Conclusions:

• Abemaciclib exhibits preferential binding to DYRK1B over DYRK1A, suggesting limitations for its use as a selective DYRK1A inhibitor.
• Understanding conserved and specific interactions aids in the rational design of DYRK isoform-selective inhibitors.
• This research offers a foundation for developing targeted therapies for DYRK-related disorders.