Sucrase

Sucrase is an enzyme that catalyzes the hydrolysis of sucrose to fructose and glucose. It is a type of glycoside hydrolase that is present in the brush border of the small intestine. Sucrase is secreted by the tips of the villi in the epithelium of the small intestine.

Function

Sucrase breaks down the sugar sucrose into its constituent parts, glucose and fructose. This is an important step in the digestion of dietary sugars. The glucose and fructose molecules can then be absorbed into the bloodstream and used by the body for energy.

Structure

Sucrase is a dimeric enzyme, with each monomer composed of five structural domains. The active site of the enzyme is located in a cleft between the third and fourth domains. The enzyme's structure is stabilized by a number of disulfide bonds.

Clinical significance

Deficiency in sucrase can lead to sucrase-isomaltase deficiency, a condition that results in diarrhea, abdominal pain, and gas due to the inability to digest sucrose and maltose. This condition is usually diagnosed in infancy and requires a diet free of sucrose and maltose.

See also

• Disaccharidase
• Isomaltase
• Lactase
• Maltase