Enterokinase (ENTK)

Enteropeptidase is an enzyme involved in human digestion. It is produced by cells in the duodenum wall, and is secreted from duodenum's glands, the crypts of Lieberkühn, whenever ingested food enters the duodenum from the stomach. Enteropeptidase has the critical job of turning trypsinogen (a zymogen) to trypsin, indirectly activating a number of pancreatic digestive enzymes.

Enteropeptidase is a serine protease enzyme (EC 3.4.21.9) which converts inactive trypsinogen into active trypsin by cleavage at the C-terminal end of the sequence. It consists of a disulfide-linked 82–140 kDa heavy chain which anchors enterokinase in the intestinal brush border membrane and a 35–62 kDa light chain which is the catalytic subunit.