title: Cholecystokinin (pancreozymin). Synthesis and properties of the N alpha-acetyl-derivative of cholecystokinin 27-33.
abstract: The acetyl-derivative of the biologically active C-terminal 7-peptide portion of cholecystokinin (CCK), N-acetyl-O-sulfate-L-tyrosyl-L-methionyl-glycyl-L-tryptophyl-L-methionyl-L-aspartyl-L-phenylalanine amide was prepared by the condensation of 2-peptide segments with 1-isobutyloxycarbonyl-2-isobutyloxy-1,2-dihydroquinoline as coupling reagent. The N-terminal residue, tyrosine was incorporated by the active ester method. The same 7-peptide was prepared also by stepwise chain-lengthening, starting with the C-terminal residue. The 9-fluorenylmethyloxycarbonyl group was applied for the protection of alpha-amino functions. In the release of amylase from acinar cells of the pancreas of guinea pigs, the acetyl-7-peptide amide was about 3 times more potent than CCK 27-33 and equal in potency to CCK 26-33. The new derivative strongly stimulated the contraction of the in situ guinea pig gall bladder.
mesh_terms: D000595:Amino Acid Sequence; D000681:Amylases / Q000378:metabolism; D000818:Animals; D002766:Cholecystokinin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology; D005704:Gallbladder / Q000187:drug effects; D006168:Guinea Pigs; D009119:Muscle Contraction / Q000187:drug effects; D010446:Peptide Fragments / Q000138:chemical synthesis* / Q000494:pharmacology; D012844:Sincalide / Q000031:analogs & derivatives*
chemical_list: D010446:Peptide Fragments; C029461:acetylcholecystokinin C-terminal heptapeptide; D002766:Cholecystokinin; D000681:Amylases; D012844:Sincalide