Fluorescence studies on the binding between 1-47 fragment of cholecystokinin receptor CCK(A)-R(1-47) and nonsulfated cholecystokinin octapeptide CCK8

The interaction between the 1-47 N-terminus fragment of the cholecystokinin receptor and the nonsulfated cholecystokinin octapeptide, CCK8, is monitored by fluorescence emission. Quenching of the fluorescence intensities is observed on binding. Dissociation constants calculated by these data are in the same submicromolar range as found for the binding of linear CCK8 analogues to B-type receptors. Although detailed structural information cannot be obtained, fluorescence emission is more sensitive than other techniques and permits fast detection of receptor-ligand interaction.