Glycosidasen

Glycosidasen (glycosidases) are enzymes that catalyze the hydrolysis of glycosidic bonds between carbohydrates or between a carbohydrate and a non-carbohydrate moiety. They constitute a large and diverse group of glycoside hydrolases that act on a variety of substrates, releasing monosaccharides or remodeling oligo- and polysaccharides.

Mechanistically, glycosidases operate by either retaining or inverting the anomeric configuration of the cleaved sugar. Typical catalytic strategies involve general acid/base catalysis and a nucleophilic residue in the active site; retaining enzymes often use a two-step double-displacement mechanism, while inverting enzymes carry out a single-step displacement. The CAZy database classifies glycosidases into numerous families based on sequence and structural features.

Biological roles of glycosidases include digestion of dietary carbohydrates (e.g., maltase, lactase), lysosomal degradation of glycoconjugates, remodeling of cell walls in plants and microbes, and processing of glycoproteins. Some glycosidases are virulence factors in pathogens, aiding tissue invasion or immune evasion.

Applications span biotechnology and medicine: they are used in food processing, glycan analysis, and as tools for synthetic transglycosylation. Clinically, deficiencies in specific glycosidases cause lysosomal storage disorders, and inhibition of certain glycosidases (for example, alpha-glucosidase inhibitors) is exploited in treating metabolic diseases. Ongoing research explores enzyme engineering, inhibitor development, and roles in cell signaling and microbiome interactions.