Monoclonal antibodies to beta-adrenergic receptors: use in purification and molecular characterization of beta receptors.

Abstract

Four hybridomas that produce monoclonal antibodies to the turkey erythrocyte .beta.1-adrenergic receptor and 1 hybridoma that produces a monoclonal antibody to the calf lung .beta.2 receptor were produced. Splenic lymphocytes from BALB/c mice immunized with partially purified turkey erythrocyte .beta.1 receptors or calf lung .beta.2 receptors were fused with the mouse myeloma line SP2/0-Ag14 to yield hybridoma cultures producing .beta. receptor monoclonal antibodies of the IgG class. The anti-turkey erythrocyte .beta. receptor antibodies precipitated partially purified .beta. receptors and inhibited adrenergic ligand binding. In contrast to autoantibodies to .beta.2-adrenergic receptors which do not crossreact with cardiac .beta.1 receptors, monoclonal antibody FV-104 chromatography directed against the adrenergic ligand binding site of turkey erythrocyte .beta. receptors crossreacted equally with calf liver and lung .beta.2 receptors and calf heart .beta.1 receptors. Some molecular homology exists between .beta.-adrenergic receptors of substantially diverse pharmacological classes. The monoclonal antibodies were used in the final stage of turkey erythrocyte .beta.1 receptor purification. Turkey erythrocyte .beta. receptors eluted from FV-104 monoclonal antibody affinity columns with NaDodSO4 [sodium dodecyl sulfate] appeared as 3 components of MW 70,000, 31,000 and 22,000 on NaDodSO4/polyacrylamide gels. Iodination of material eluted from immunoaffinity columns with propranolol demonstrated the existence of only a single component (MW 70,000), indicating that the turkey erythrocyte .beta.1 receptor can be purified to homogeneity.