Altered galectin glycosylation: potential factor for the diagnostics and therapeutics of various cardiovascular and neurological disorders

Abstract

Galectins are β-galactoside binding mammalian proteins characterized by the presence of a conserved carbohydrate recognition domain, expressed in almost all taxa of living organisms and involved in broad range of significant biological and physiological functions. Previously, we reported the purification and extensive characterization of galectin-1 from goat (Capra hircus) heart. Interestingly, the purified protein was found to have significant level of glycosylation. This intrigued us to evaluate the involvement of glycosylation in relation to protein's structural and functional integrity in its purified form. In the present study, an extensive comparative physicochemical characterization has been performed between the glycosylated and deglycosylated form of the purified protein. Deglycosylation resulted in an enhanced fluorescence quenching and marked reduction in pH and thermal stability of the purified galectin. Exposure to various biologically active chemicals showed significant differences in the properties and stability profile, causing significant deviations from its regular secondary structure in the deglycosylated form. These results clearly indicated enhanced structural and functional stabilization in the glycosylated galectin. The data revealed herein adds a vital facet demonstrating the significance of galectin expression and glycosylation in causation, progression, and possible therapeutics of associated clinical disorders. Our approach also allowed us to define some key interactions between the purified galectin and carbohydrate ligands that could well serve as an important landmark for designing new drug protocols for various cardiovascular and neurological disorders.