SRC2-3 binds to vitamin D receptor with high sensitivity and strong affinity

Area of Science:

• Molecular biology
• Structural biology
• Endocrinology

Background:

• The Vitamin D receptor (VDR) is a nuclear receptor crucial for gene regulation.
• Coactivator binding to the VDR/ligand complex is essential for target gene expression.
• Precise interactions between VDR and coactivators remain incompletely understood.

Purpose of the Study:

• To synthesize and characterize coactivator peptides DRIP205-2 and SRC2-3.
• To evaluate their binding affinity and interaction modes with the VDR ligand-binding domain (LBD).
• To assess the influence of different VDR ligands (agonist, partial agonist, antagonist) on these interactions.

Main Methods:

• Synthesis of coactivator peptides DRIP205-2 and SRC2-3.
• Surface plasmon resonance (SPR) to measure binding affinity to VDR-LBD.
• X-ray crystallographic analysis to determine interaction modes.

Main Results:

• Both peptides bound to the VDR-LBD.
• The SRC2-3 peptide exhibited higher sensitivity to VDR ligands (agonist, partial agonist, antagonist).
• SRC2-3 showed more intimate interactions with VDR-LBD compared to DRIP205-2.

Conclusions:

• The SRC2-3 peptide is a more effective coactivator for VDR in the presence of various ligands.
• Understanding these specific interactions can inform the development of VDR-targeting therapeutics.