Pure β-adrenergic receptor: the single polypeptide confers catecholamine responsiveness to adenylate cyclase

Abstract

The .beta.-adrenergic receptor binding subunits from frog erythrocytes, hamster lung and guinea pig lung were purified to apparent hmogeneity and in all cases reside on a single polypeptide. Insertion of the pure receptors into phospholipid vesicles and subsequent fusion of these vesicles with a receptor-deficient cell conveys .beta.-adrenergic responsiveness to the adenylate cyclase system of the acceptor cell. Such responsiveness is linearly dependent on the amount of receptor used in the fusion experiments and is independent of the receptor source. This responsiveness displays appropriate .beta.-adrenergic specificity. Evidently, the .beta.-adrenergic receptor polypeptide contains both the ligand binding site and the site responsible for mediating stimulation of adenylate cyclase activity, presumably via interaction with the guanine nucleotide regulatory protein.