High-throughput screening assay for new ligands at human melatonin receptors

Abstract

Aim: Melatonin (MT) is a neurohormone produced and secreted primarily by the pineal gland in a circadian manner, and mainly acts through 2 receptor subtypes: MT 1 and MT 2 in humans. The diversity in their tissue distribution is in favor of different functions for each receptor subtype. Selective modulators are therefore required to determine the physiological roles of these melatonin receptor subtypes and their implications in pathological processes. Methods: A homogenous MT 1 /MT 2 receptor binding assay was established for high-throughput screening of new ligands at the hMT 1 and/or hMT 2 receptors. The functional properties (agonists or antagonists) were assessed by a conventional guanosine-5'[γ-35 S] triphosphate (GTP-γS) assay. Results: Three hMT 1 receptor-selective small molecule antagonists and 1 hMT 2 receptor-selective small molecule antagonist with novel structural features were identified following a high-throughput screening campaign of 48 240 synthetic and natural compounds. Conclusion: The findings may assist in the expansion of chemical probes to these 2 receptor subtypes.

New Radioligands for Describing the Molecular Pharmacology of MT1 and MT2 Melatonin Receptors

“…For DIV880, the process was a little different. The compound is an iodinated analog of a bromo-compound that resulted from a large screening process, similar to the compounds described elsewhere [11,12]. This compound was specific to MT 2 , with a pK i 2 logs “better” for MT 2 than for MT 1 .…”

“…The aim was to broaden the panel of available tools for studying these receptors [3,10]. By conducting several series of high throughput screening HTS campaigns [11,12], we found a MT 2 -specific partial agonist, DIV880. The K i of this compound is 2 logs less potent with MT 1 than MT 2 .…”

Recombinant Human Melatonin Receptor MT1 Isolated in Mixed Detergents Shows Pharmacology Similar to That in Mammalian Cell Membranes

“…These findings validated the quality of the purified material, indicating that it may be of particular interest for primary screening of MT1-binding molecules. Purified MT1 samples could be very helpful for limiting the false positive rate usually experienced with classical screenings, since no cellular or membranous artifacts would be present to interfere with the assay , . Obviously, this assay format would be unable to indicate the G-protein coupling and signaling properties of the compounds, which are known to be important, particularly in the melatoninergic system [19].…”

Discovery of potent inhibitors for phosphodiesterase 5 by virtual screening and pharmacophore analysis

“…Both of them were used for improve reliability. The major benefit of CADD in drug discovery is that it costs much less than any biomedical test of inhibition in cells just like in the references from APS [22][23][24][25][26][27][28] . The ligand based method is built on regression analysis for molecular structure and properties against activities, while the protein based method focuses on the docking procedure in which the structure of the protein would be docked with many kinds of inhibitors and the binding energies would be calculated [29,30] .…”