Isomaltase

Isomaltase is an enzyme that plays a crucial role in the digestion of carbohydrates, specifically by breaking down isomaltose into two molecules of glucose. This enzyme is part of the maltase-glucoamylase complex that is located on the brush border of the small intestine, where it facilitates the final steps of carbohydrate digestion. Isomaltase works in tandem with other digestive enzymes, such as sucrase, lactase, and maltase, to ensure the efficient absorption of nutrients from the diet.

Function

The primary function of isomaltase is to catalyze the hydrolysis of isomaltose, a disaccharide produced from the digestion of starches, into two glucose molecules. Glucose is a vital source of energy for the body and is absorbed into the bloodstream through the intestinal walls. By converting isomaltose into glucose, isomaltase plays a critical role in maintaining blood glucose levels and providing energy for cellular functions.

Genetics

The gene responsible for encoding the isomaltase component of the maltase-glucoamylase enzyme is located on chromosome 7. Mutations in this gene can lead to deficiencies in isomaltase activity, which can result in disorders of carbohydrate digestion and absorption.

Clinical Significance

Isomaltase deficiency, also known as sucrase-isomaltase deficiency, is a rare genetic disorder characterized by the inability to digest certain sugars, leading to symptoms such as diarrhea, abdominal pain, and bloating after consuming foods containing sucrose or starch. Diagnosis typically involves a combination of breath tests, genetic testing, and sometimes small intestine biopsy. Management of the condition often requires dietary modifications to avoid foods containing the problematic sugars.

See Also

• Digestive enzyme
• Carbohydrate metabolism
• Sucrase-isomaltase deficiency
• Glucose