The molecule is a decapeptide comprising 5-oxoprolyl, glutamyl, aspartyl, O-sulfotyrosyl, threonyl, glycyl, tryptopyl, methionyl, aspartyl and phenylalaninamide residues in sequence. Found in the skins of certain Australian amphibians, it is an analogue of the gastrointestinal peptide hormone cholecystokinin and stimulates gastric, biliary, and pancreatic secretion. It is used in cases of paralysis of the intestine (paralytic ileus) and as a diagnostic aid in pancreatic malfunction. It has a role as a diagnostic agent and a gastrointestinal drug.
(3S)-3-[[(2S)-5-amino-5-oxo-2-[[(2S)-5-oxopyrrolidine-2-carbonyl]amino]pentanoyl]amino]-4-[[(2S)-1-[[(2S,3R)-1-[[2-[[(2S)-1-[[(2S)-1-[[(2S)-1-[[(2S)-1-amino-1-oxo-3-phenylpropan-2-yl]amino]-3-carboxy-1-oxopropan-2-yl]amino]-4-methylsulfanyl-1-oxobutan-2-yl]amino]-3-(1H-indol-3-yl)-1-oxopropan-2-yl]amino]-2-oxoethyl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-1-oxo-3-(4-sulfooxyphenyl)propan-2-yl]amino]-4-oxobutanoic acid