Disackaridaser

Disackaridaser is a term that appears infrequently in biochemical literature and is generally considered a nonstandard or translational variant of disaccharidase. In contemporary nomenclature, the enzymes that hydrolyze disaccharides are called disaccharidases, and if used, disackaridaser would refer to the same broad class of enzymes that split disaccharides into monosaccharides.

Disaccharidases catalyze the hydrolysis of disaccharides such as sucrose, lactose, and maltose into their constituent monosaccharides. The typical reaction consumes a molecule of water and yields two simple sugars (for example, sucrose + water → glucose + fructose). In humans, the major brush-border disaccharidases are lactase, sucrase, maltase, and isomaltase, which are organized in membrane-bound complexes on the intestinal epithelium and act during the final steps of carbohydrate digestion.

Occurrence and mechanism: Disaccharidases are commonly found on the luminal surface of enterocytes in the small intestine, where they function as membrane-bound enzymes. Many are glycoproteins whose catalytic activity can depend on the local ionic environment and may require appropriate folding and anchoring in the brush border. Across organisms, there is diversity in the specific disaccharidases present and their substrate specificities.

Clinical relevance: Deficiency of a disaccharidase, most notably lactase, leads to impaired digestion of its corresponding disaccharide and can cause carbohydrate malabsorption symptoms ("lactose intolerance"). Rare genetic disorders, such as congenital sucrase–isomaltase deficiency, involve multiple disaccharidases. Diagnosis can involve enzyme activity assays or genetic testing, informing dietary management and treatment strategies. See also disaccharide, lactase, sucrase, maltase.