Use of Cholate/Sodium Chloride for Solubilisation of Brain D2 Dopamine Receptors

Abstract

The use of cholate (in the presence of NaCl) is described for solubilizing bovine brain D2 dopamine receptors. The method gives in high yield a preparation of solubilized D2 receptors, which when assayed by [3H]spiperone binding show little interference from nonspecific and nonstereospecific binding sites. Characterization by ultrafiltration, EM, gel filtration and sucrose density gradient centrifugation was achieved, showing the receptors to be truly solubilized. Pharmacological characterization using [3H]spiperone binding suggested the presence of serotonergic S2 receptors in addition to D2 receptors. The pharmacological properties of the solubilized D2 receptors show a good correlation with those of membrane-bound receptors, although ligand binding affinities are lower in the solubilized preparation.