Intestinal α-glucosidase

Intestinal α-glucosidase is an enzyme localized in the brush border of the small intestine and is responsible for final carbohydrate digestion. It hydrolyzes terminal, non-reducing (1→4)-linked α-glucose residues from oligosaccharides and disaccharides, releasing free α-glucose, which is then absorbed. This function is critical for the conversion of dietary starches and other carbohydrates into absorbable glucose, impacting postprandial blood sugar levels. Structurally, intestinal α-glucosidases are glycoside hydrolases in family GH31, with important forms including sucrase-isomaltase and maltase-glucoamylase complexes, each containing multiple catalytic subunits. Clinically, these enzymes are therapeutic targets for drugs such as acarbose, miglitol, and voglibose used in type 2 diabetes to slow glucose absorption and manage hyperglycemia. Inhibition of intestinal α-glucosidases can cause gastrointestinal adverse effects due to increased undigested carbohydrates reaching the colon.

Other names

Maltase-glucoamylaseSucrase-isomaltaseα-D-glucoside glucohydrolase

Competitive inhibition of α-glucosidase activity (drugs block intestinal α-glucosidases, reducing carbohydrate absorption and subsequent glucose rise)