Galectin-4 N-Terminal Domain: Binding Preferences Toward A and B Antigens With Different Peripheral Core...

Area of Science:

• Biochemistry
• Structural Biology
• Immunology

Background:

• Galectin-4 (Gal-4) is a tandem-repeat protein with two domains.
• Both domains bind A and B histo-blood group antigens with varying affinities.
• The biological significance of Gal-4-antigen interactions, potentially in pathogen recognition, remains unclear.

Purpose of the Study:

• To investigate the binding of the N-terminal domain of Gal-4 to various A and B oligosaccharide antigens.
• To elucidate the structural basis for Gal-4's binding preferences among related antigens.

Main Methods:

• Nuclear Magnetic Resonance (NMR) spectroscopy
• Isothermal Titration Calorimetry (ITC)
• Molecular modeling

Main Results:

• The N-terminal domain of Gal-4 exhibits distinct binding affinities for different A and B oligosaccharide antigens.
• Subtle chemical modifications in the oligosaccharide antigens lead to specific changes in binding affinity and intermolecular interactions.
• Structural insights into the binding mechanism were obtained.

Conclusions:

• The study provides a structural rationale for the observed binding preferences of the Gal-4 N-terminal domain.
• Understanding these interactions is crucial for elucidating Gal-4's role in biological processes, including pathogen recognition.