Enteropeptidase (previously also enterokinase) is a serine protease enzyme () secreted by intestinal gland cells in the crypts of Lieberkühn the in the small intestine. Enterokinase activates trypsinogen, a zymogen, to trypsin, indirectly activating a number of pancreatic digestive enzymes.

Reaction

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Overview: trypsinogen + enterokinase → trypsin + octapeptide

Nomenclature

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Despite its older name of enterokinase, the enzyme is not a kinase, since it activates its substrate by cleavage and not phosphorylation.

Genetics

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Enteropeptidase is encoded by the PRSS7 (serine protease-7 gene) or ENTK gene on the 21st chromosome (21q21).

Isolated cases of enterokinase deficiency have been reported (OMIM).

External link

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EC 3.4.21 | Enterokinase