Annalida Bedini, Gian Marco Elisi, Fabiola Fanini, Michele Retini, Laura Scalvini, Silvia Pasquini, Chiara Contri, Katia Varani, Gilberto Spadoni, Marco Mor, Fabrizio Vincenzi, Silvia Rivara
The labeled ligand commonly employed in competition binding studies for melatonin receptor ligands, 2-[125 I]iodomelatonin, showed slow dissociation with different half-lives at the two receptor subtypes. This may affect the operational measures of affinity constants, which at short incubation times could not be obtained in equilibrium conditions, and structure-activity relationships, as the Ki values of tested ligands could depend on either interaction at the binding site or the dissociation path. To address these issues, the kinetic and saturation binding parameters of 2-[125 I]iodomelatonin as well as the competition constants for a series of representative ligands were measured at a short (2 h) and a long (20 h) incubation time...
March 2024: Journal of Pineal Research