Anthranilic Acid Based CCK1 Receptor Antagonists and CCK-8 Have a Common Step in Their “Receptor Desmodynamic Processes”

The interaction between the 1−47 N-terminus of the CCK1-R and the anthranilic acid based antagonists has been investigated by fluorescence spectroscopy. These antagonists interact with W39 of the N-terminal domain of the CCK1-R like that of the endogenous ligand CCK-8. This specific interaction was not found in other nonpeptide ligands of the CCK1-R. Conformational studies, using NMR and energy minimization procedures, have allowed formulation of a new hypothesis on the CCK1-R binding mode of the anthranilic antagonists.