Replacement of Glycine with Dicarbonyl and Related Moieties in Analogues of the C-Terminal Pentapeptide of Cholecystokinin: CCK<sub>2</sub> Agonists Displaying a Novel Binding Mode
known to possess sufficient structural features for CCK(2) recognition, none shares the properties of BC 264. Hence we have developed new short peptidic or pseudo-peptidic derivatives containing the C-terminal tetrapeptide of BC 264. Our results indicate that some compounds characterized by the presence of two carbonyl groups at the N-terminus, as in 2b (HO(2)C-CH(2)-CONH-Trp-(NMe)Nle-Asp-Phe-NH(2)), are