This peptide hormone induces gall bladder contraction and the release of pancreatic enzymes in the gut. Its function in the brain is not clear (By similarity). Highly concentrated in the duodenum. Also localized in more distal parts of the small intestine. The precursor is cleaved by proteases to produce a number of active cholecystokinins. Tyrosyl sulfated. Tyrosyl sulfated. Belongs to the gastrin/cholecystokinin family.