Intestinal brush-border alpha-glucosidase (Alpha-glucosidase)

Intestinal brush-border alpha-glucosidases are a group of essential digestive enzymes, primarily sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM), located on the luminal surface of the small intestinal enterocytes. These enzymes catalyze the final step of carbohydrate digestion by hydrolyzing oligosaccharides and disaccharides into absorbable monosaccharides like glucose and fructose (UniProt: P14410, O43451). By breaking down alpha-1,4 and alpha-1,6 glycosidic linkages, they play a critical role in determining the rate of glucose entry into the systemic circulation. In the context of metabolic disease, these enzymes are primary therapeutic targets for managing type 2 diabetes. Alpha-glucosidase inhibitors (AGIs) like acarbose and miglitol competitively bind to these enzymes, delaying carbohydrate absorption and effectively flattening postprandial glucose spikes (PubMed: 15181025). While highly effective for glycemic control, their use is often limited by gastrointestinal side effects resulting from the fermentation of undigested carbohydrates by colonic bacteria (NIH: NBK493214).

Other names

Intestinal alpha-glucosidaseSucrase-isomaltase (SI)Maltase-glucoamylase (MGAM)DisaccharidaseGlucosidaseExo-alpha-1,4-glucosidase

Competitive inhibition of intestinal alpha-glucosidase enzymes (sucrase, maltase, and glucoamylase) in the brush border of the small intestine, which delays the hydrolysis of complex carbohydrates and slows the absorption of glucose, thereby reducing postprandial blood glucose excursions (StatPearls, 2023; PubMed: 10628632).