title: Receptor fragment approach to the binding between CCK8 peptide and cholecystokinin receptors: a fluorescence study on type B receptor fragment CCK(B)-R (352-379).
abstract: Fluorescence titrations in a membrane mimetic solvent system allowed us to estimate that the dissociation constant of the bimolecular complex between CCK8 peptide and cholecystokinin type B receptor fragment CCK(B)-R (352-379) is in the micromolar range. When considered in the context of the full receptor/ligand model, these experiments demonstrate that the receptor fragment chosen on the basis of previous structural studies represents a reliable model system to monitor the ability of CCK8 or CCK8 analogs to bind the cholecystokinin receptor. Together with previous studies, this confirms that the receptor fragment approach adopted to define the binding mode of the CCK8 fragment of cholecystokinin with its two receptors, CCK(A) and CCK(B,) can be used to characterize the binding from the equilibrium standpoint. In this context, fluorescence spectroscopy proves to be the favored technique to measure dissociation constants in the nanomolar to micromolar range.
authors.affiliation: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi (CIRPEB) and Dipartimento di Chimica Biologica, Università Federico II, Via Mezzocannone 6/8, Naples, I-80134, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: De Luca
authors.forename: Marina
authors.initials: M
authors.lastname: Sanseverino
authors.forename: Ivana
authors.initials: I
authors.lastname: Zocchi
authors.forename: Carlo
authors.initials: C
authors.lastname: Pedone
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Morelli
authors.forename: Raffaele
authors.initials: R
authors.lastname: Ragone
mesh_terms: D002766:Cholecystokinin / Q000737:chemistry / Q000378:metabolism*; D002942:Circular Dichroism; D005453:Fluorescence; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism*; D043887:Receptor, Cholecystokinin B / Q000737:chemistry* / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D010446:Peptide Fragments; D043887:Receptor, Cholecystokinin B; D002766:Cholecystokinin