The study of multivalent carbohydrate-protein interactions by bio-layer interferometry.

Area of Science:

• Biochemistry
• Chemical Biology
• Biophysics

Background:

• Complex multivalent carbohydrate-protein interactions are challenging to study.
• Aggregation issues often hinder analysis using standard biophysical techniques.
• Accurate kinetic and thermodynamic data are crucial for understanding these interactions.

Purpose of the Study:

• To evaluate bio-layer interferometry (BLI) as a complementary method for studying multivalent carbohydrate-protein interactions.
• To demonstrate BLI's ability to overcome aggregation problems.
• To measure kinetic and thermodynamic parameters of specific multivalent interactions.

Main Methods:

• Utilized bio-layer interferometry (BLI).
• Employed tetra- and hexadecavalent N-acetylgalactosamine (GalNAc) glycoconjugates.
• Used Helix pomatia agglutinin (HPA) as a model lectin.
• Compared BLI with Surface Plasmon Resonance (SPR) and Isothermal Titration Calorimetry (ITC).

Main Results:

• Bio-layer interferometry proved to be an excellent complementary technique.
• Reliable kinetic and thermodynamic parameters were obtained for multivalent interactions.
• Measurements spanned a range from micro- to nanomolar affinity.
• BLI successfully circumvented aggregation issues encountered with other methods.

Conclusions:

• Bio-layer interferometry is a robust method for characterizing complex multivalent carbohydrate-protein interactions.
• BLI offers a valuable alternative or complement to SPR and ITC, especially when aggregation is a concern.
• The study provides a reliable platform for quantifying the binding kinetics and thermodynamics of glycoconjugates with lectins.