TY - JOUR
T1 - Discovery of 2-(Imidazo[1,2-b]pyridazin-2-yl)acetic Acid as a New Class of Ligands Selective for the γ-Hydroxybutyric Acid (GHB) High-Affinity Binding Sites
AU - Krall, Jacob
AU - Bavo, Francesco
AU - Falk-Petersen, Christina B
AU - Jensen, Claus Hatt
AU - Nielsen, Julie Olsson
AU - Tian, Yongsong
AU - Anglani, Valeria
AU - Kongstad, Kenneth Thermann
AU - Piilgaard, Louise
AU - Nielsen, Birgitte
AU - Gloriam, David E
AU - Kehler, Jan
AU - Jensen, Anders A.
AU - Harpsøe, Kasper
AU - Wellendorph, Petrine
AU - Frølund, Bente
PY - 2019/3/14
Y1 - 2019/3/14
N2 - Gabazine, a γ-aminobutyric acid type A (GABAA) receptor antagonist, has previously been reported to inhibit the binding of [3H]NCS-382, a representative ligand of the high-affinity binding site for the neuroactive substance γ-hydroxybutyric acid (GHB). We herein report a study on the structural determinants of gabazine for binding to (i) the orthosteric binding site of the GABAA receptor and (ii) the high-affinity GHB binding site. Expanding the structural diversity of available ligands for the high-affinity GHB binding sites, this study identified 2-(imidazo[1,2-b]pyridazin-2-yl)acetic acid as a novel ligand-scaffold leading to analogues with relatively high affinity (Ki 0.19-2.19 μM) and >50 times selectivity for the [3H]NCS-382 over [3H]muscimol binding sites. These results highlight that gabazine interacts with the high-affinity GHB and orthosteric GABAA receptor binding sites differently and that distinct analogues can be generated to select between them. To facilitate further in vivo studies, a promising prodrug candidate for brain delivery was identified.
AB - Gabazine, a γ-aminobutyric acid type A (GABAA) receptor antagonist, has previously been reported to inhibit the binding of [3H]NCS-382, a representative ligand of the high-affinity binding site for the neuroactive substance γ-hydroxybutyric acid (GHB). We herein report a study on the structural determinants of gabazine for binding to (i) the orthosteric binding site of the GABAA receptor and (ii) the high-affinity GHB binding site. Expanding the structural diversity of available ligands for the high-affinity GHB binding sites, this study identified 2-(imidazo[1,2-b]pyridazin-2-yl)acetic acid as a novel ligand-scaffold leading to analogues with relatively high affinity (Ki 0.19-2.19 μM) and >50 times selectivity for the [3H]NCS-382 over [3H]muscimol binding sites. These results highlight that gabazine interacts with the high-affinity GHB and orthosteric GABAA receptor binding sites differently and that distinct analogues can be generated to select between them. To facilitate further in vivo studies, a promising prodrug candidate for brain delivery was identified.
U2 - 10.1021/acs.jmedchem.9b00131
DO - 10.1021/acs.jmedchem.9b00131
M3 - Journal article
C2 - 30763084
SN - 0022-2623
VL - 62
SP - 2798
EP - 2813
JO - Journal of Medicinal Chemistry
JF - Journal of Medicinal Chemistry
IS - 5
ER -