title: Synthesis and biological evaluation of cyclic and branched peptide analogues as ligands for cholecystokinin type 1 receptor.
abstract: A library of cyclic CCK8 analogues, containing unnatural amino acids in the peptide sequence, is prepared using solid-phase synthesis. The structure of these cyclic peptides is based on a previously synthesised compound, cyclo-CCK8, selective for CCK(1) receptor. Structure-activity investigations are performed by evaluating the binding properties of the new analogues. In particular, the binding ability of the cyclic CCK8 analogues is tested by nuclear medicine studies on cell line transfected with CCK(1) receptor. Compounds named cyclo-A4-cyclo-A7 show binding constant in the range 6.0-8.0 microM, with an improved affinity over the previous described cyclo-CCK8, but almost comparable IC(50) values among new analogues towards CCK(1) were obtained.
authors.affiliation: Istituto di Biostrutture e Bioimmagini CNR, & Centro Interuniversitario per la Ricerca sui Peptidi Bioattivi (CIRPeB), via Mezzocannone, Napoli, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: De Luca
authors.forename: Antonia
authors.initials: A
authors.lastname: De Capua
authors.forename: Michele
authors.initials: M
authors.lastname: Saviano
authors.forename: Raffaella
authors.initials: R
authors.lastname: Della Moglie
authors.forename: Luigi
authors.initials: L
authors.lastname: Aloj
authors.forename: Laura
authors.initials: L
authors.lastname: Tarallo
authors.forename: Carlo
authors.initials: C
authors.lastname: Pedone
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Morelli
mesh_terms: D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D003500:Cyclization; D006801:Humans; D020128:Inhibitory Concentration 50; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D019151:Peptide Library; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D011949:Receptors, Cholecystokinin / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D008024:Ligands; D019151:Peptide Library; D010455:Peptides; D011949:Receptors, Cholecystokinin