Probing the ligand-binding pocket of recombinant β-lactoglobulin: Calorimetric and spectroscopic studies

beta-Lactoglobulin (BLG), a member of the lipocalin family, is a well-studied model protein. It is also widely used as a scaffold for the development of novel proteins. Our previous work adopted a rational approach based on homolog structure alignment to obtain several BLG variants with point mutations inside the binding pocket. To investigate the effect of mutation on ligand binding thermodynamics, we chose a set of aliphatic ligands and performed a study based on isothermal titration calorimetry. In addition, the circular dichroism spectra observed for the protein-ligand complexes were analyzed. The ligand binding thermodynamics was compared between wild-type and mutated BLG as well as between two ligands. The findings pointed to factors that can be responsible for the mutation-induced changes in the thermodynamics of the complexes.

Automated summary

In this study, BLG variants with point mutations inside the binding pocket were obtained using a rational approach based on homolog structure alignment. The effect of these mutations on ligand binding thermodynamics was investigated using isothermal titration calorimetry, and circular dichroism spectra of the protein-ligand complexes were analyzed. The findings provide insights into the factors responsible for mutation-induced changes in the thermodynamics of the complexes.