enteropeptidaz

Enteropeptidase, also known as enterokinase, is a digestive enzyme produced by cells of the duodenum, the first section of the small intestine. It is a serine protease, meaning it belongs to a class of enzymes that use a serine residue in their active site to catalyze the hydrolysis of peptide bonds. The primary and most critical function of enteropeptidase is to activate trypsinogen, an inactive zymogen precursor of the enzyme trypsin. This activation is initiated in the duodenum, where trypsinogen is secreted by the pancreas.

The activation of trypsinogen by enteropeptidase is a crucial step in the cascade of pancreatic enzyme activation. Once trypsinogen is cleaved by enteropeptidase to form active trypsin, trypsin can then auto-activate more trypsinogen and also activate other pancreatic zymogens, such as chymotrypsinogen, procarboxypeptidase, and proelastase. These activated enzymes are essential for the digestion of proteins into smaller peptides and amino acids, facilitating their absorption in the small intestine.

Enteropeptidase is synthesized as an inactive precursor and is stored in the brush border membranes of duodenal enterocytes. Its activity is highly specific, cleaving trypsinogen at a single site. This specificity ensures that the digestive process begins in the correct location and in a controlled manner. Genetic mutations affecting enteropeptidase production or function can lead to a deficiency, resulting in protein malnutrition due to impaired digestion, a condition known as congenital enteropeptidase deficiency.