Sucrase domain of intestinal sucrase-isomaltase (SI)

The sucrase domain of intestinal sucrase-isomaltase is a critical enzymatic component of the small intestinal brush border, primarily responsible for the hydrolysis of sucrose into glucose and fructose. As a member of the glycoside hydrolase family 31 (GH31), it also contributes significantly to the digestion of maltose and other alpha-1,4-linked glucose oligomers. This domain is part of a larger bifunctional protein, sucrase-isomaltase (SI), which is essential for the final stages of dietary carbohydrate processing. Mutations in the sucrase domain or the SI gene lead to congenital sucrase-isomaltase deficiency (CSID), a condition resulting in malabsorption and severe gastrointestinal symptoms like osmotic diarrhea. Conversely, the sucrase domain is a therapeutic target for alpha-glucosidase inhibitors such as acarbose, which are used to manage postprandial blood glucose levels in type 2 diabetes. For patients with CSID, sacrosidase serves as an enzyme replacement therapy to restore sucrase activity and alleviate symptoms.

Other names

SucraseSUCC-terminal domain of sucrase-isomaltaseSucrose alpha-glucosidaseIntestinal sucraseSI sucrase domain

Enzyme replacement therapy; Competitive inhibition of alpha-glucosidase