Structural characterization of Galectins and Galectin-Related Protein

Galectins are a family of beta-galactoside-binding proteins located in a wide range of organisms, where they exert functions that can be mediated by carbohydrate-protein and protein-protein interactions. Using a protein engineering approach, galectin-3 constructs were produced and set to perform structural studies, which allowed to ascertain the position of key amino acids in the N-terminal playing fundamental roles in galectin-3 function, like apoptosis and metastasis. On the other hand, a comprehensive genetic mapping of the galectin family identified one particular Galectin-Related Protein located in bone marrow that has a high degree of sequence identity with galectins, sharing their jelly-roll characteristic folding. Interestingly, GRP does not bind beta-galactosides. In order to study in detail the entirety of the galectin family for themes of divergence and recognition within a limited number of proteins, G. gallus GRP was chosen as model. This protein's structural resolution showed the particular hallmarks that hinder beta-galactoside binding.