Membranes from a HEK-293 cell line expressing the
2-adrenergic receptor (
2-AR) have been immobilized on anartificial membrane liquid chromatographic stationaryphase. The resulting phase was packed into a glasscolumn (1.8 × 0.5 (i.d.) cm) and used in on-line chromatographic system. Frontal displacement affinity chromatography was used to determine the dissociationconstants (
Kd) of CGP 12177A (552.6 nM) and (
S)-propranolol (84.3 nM). Zonal displacement chromatography using CGP 12177A as the marker and racemicmixtures of the antagonists nadolol and propranololdemonstrated that the immobilized
2-AR retained itsability to specifically bind these compounds. Similarexperiments with (
R)- and (
S)-propranolol demonstratedthat the immobilized receptor retained its enantioselectivity as (
S)-propranolol displaced the CGP 12177 markerto a great extent that the (
R)-enantiomer. The addition ofthe agonist butoxamine to the mobile phase increased theretention of the CGP-12177A as did the addition of theagonist fenoterol. These results indicate that the immobilized
2-AR retained its ability to undergo ligand-induced conformational changes. The data from this studysuggest that the immobilized
2-AR can be used to screenfor ligand binding interactions in both the resting andactive states of the receptor.