Analysis of the behavioral activity of C- and N-terminal fragments of cholecystokinin octapeptide.
Cholecystokinin (CCK) is a gut peptide which induces a syndrome of satiety, including reduced food intake and reduced exploratory behaviors. To investigate the minimal active sequence within the octapeptide molecule for reducing exploratory behavior, all C- and N-terminal fragments of CCK 26-33 (CCK8) were synthesized. Only CCK26-33 [H-Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2] and CCK 27-33 [H-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2] induced the behavioral effects within a physiological dose range. Smaller fragments as well as unsulfated CCK26-33 and CCK27-33 were inactive in doses as high as 10(-3) mol/kg. The requirement of the entire C-terminal heptapeptide for the behavioral effects of CCK is contrasted against the activity of smaller fragments at pancreatic, gastrointestinal and brain CCK receptors.
D000595:Amino Acid Sequence; D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology; D005106:Exploratory Behavior / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D008297:Male; D051379:Mice; D008970:Molecular Weight; D010446:Peptide Fragments / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D011949:Receptors, Cholecystokinin; D012844:Sincalide / Q000032:analysis*
D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D011949:Receptors, Cholecystokinin; C025997:cholecystokinin (27-33); D002766:Cholecystokinin; D012844:Sincalide