Altering the Modular Architecture of Galectins Affects its Binding with Synthetic α‐Dystroglycan O‐Mannosylated Core M1 Glycoconjugates In situ

The multifunctionality of galectins helps regulate a broad range of fundamental cellular processes via cis‐binding and trans‐bridging activities and has gained widespread attention with respect to the importance of the natural specificity/selectivity of this lectin family to its glycoconjugate receptors. Combining galectin (Gal)‐1, −3, −4, and −9 variant test panels, achieved via rational protein engineering, and a synthetic α‐dystroglycan (DG) O‐Mannosylated core M1 glycopeptide library, a detailed comparative analysis was performed, utilizing microarray experiments to delineate the design‐functionality relationships within this lectin family. Enhancement of prototype Gal‐1 and chimera‐type Gal‐3 cis‐binding toward the prepared ligands is possible by transforming these lectins into tandem‐repeat type and prototypes, respectively. Furthermore, Gal‐1 variants demonstrated improved trans‐bridging capabilities between core M1 α‐DG glycopeptides and laminins in microarray, suggesting the possible translational applications of these galectin variants in the treatment of some forms of α‐dystroglycanopathy. The alteration of galectin modular architecture effectively revealed the design‐functionality relationship of lectin binding towards α‐dystroglycan O‐Mannosylated core M1 glycopeptides in situ. Altering galectin modular architecture via rational protein engineering revealed the design‐functionality relationship within this lectin family towards its affinity to α‐dystroglycan O‐Mannosylated core M1 glycopeptides in situ. Transforming galectin‐1 and −3 into tandem‐repeat‐ and proto‐types, respectively, significantly enhanced cis‐binding with the prepared ligands. Moreover, Gal‐1 variants demonstrated higher trans‐bridging capabilities between α‐dystoglycan glycoconjugates and laminins compared to Gal‐1 wild‐type.