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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)
Author(s) -
De Luca Stefania,
Sanseverino Marina,
Zocchi Ivana,
Pedone Carlo,
Morelli Giancarlo,
Ragone Raffaele
Publication year - 2005
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20222
Subject(s) - chemistry , cholecystokinin receptor , cholecystokinin , receptor , dissociation constant , context (archaeology) , peptide , fluorescence , stereochemistry , biophysics , dissociation (chemistry) , biochemistry , biology , paleontology , physics , quantum mechanics
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. © 2005 Wiley Periodicals, Inc. Biopolymers, 2005