Characterization of novel benzodiazepine ligands in Spodotera frugiperda (Sf-9) insect cells

Abstract The goals of the present work were to characterize the binding profile of nine benzodiazepine ligands in Spodotera frugiperda (Sf-9) insect cells expressing specific gamma aminobutyric acid A (GABA A ) receptor subunit combinations and compare the affinities to those for the receptors in the rat cerebellum. Three recombinant baculovirus constructs, each harboring a different GABA A receptor subunit, were introduced into insect cells by simultaneous infection. Saturation and competition binding assays were carried out in membranes from Sf-9 cells infected with either α 1 β 2 γ 2 or α 6 β 2 γ 2 subunit combinations. The affinities of the ligands to the α 1 β 2 γ 2 or α 6 β 2 γ 2 receptors expressed in Sf-9 cells were similar to the affinities previously determined for the α 1 or α 6 subunit-containing GABA A receptors in the rat cerebellum, respectively, thus confirming the previously assigned receptor types in the cerebellum.