This peptide hormone induces gall bladder contraction and the release of pancreatic enzymes in the gut. Its function in the brain is not clear. Binding to CCK-A receptors stimulates amylase release from the pancreas, binding to CCK-B receptors stimulates gastric acid secretion. Binds to CCK-A receptors in the pancreas and CCK-B receptors in the brain. The precursor is cleaved by proteases to produce a number of active cholecystokinins. The precursor is cleaved by ACE, which removes the Gly-Arg-Arg peptide at the C-terminus, leading to mature hormone. Belongs to the gastrin/cholecystokinin family. Cholecystokinin entry