Abstract
We have developed four hybridomas that produce monoclonal antibodies to the turkey erythrocyte beta 1-adrenergic receptor and one hybridoma that produces a monoclonal antibody to the calf lung beta 2 receptor. Splenic lymphocytes from BALB/c mice immunized with partially purified turkey erythrocyte beta 1 receptors or calf lung beta 2 receptors were used with the mouse myeloma line SP2/O-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 [Venter, J. C., Fraser, C. M. & Harrison, L. C. (1980) Science 207, 1361-1363] which do not crossreact with cardiac beta 1 receptors, monoclonal antibody FV-104 directed against the adrenergic ligand binding site of turkey erythrocyte beta receptors crossreacted equally with calf liver and lung beta 2 receptors as well as calf heart beta 1 receptors. These data suggest that some molecular homology exists between beta-adrenergic receptors of substantially diverse pharmacological classes. We utilized the monoclonal antibodies in the final stage of turkey erythrocyte beta 1 receptor purification. Turkey erythrocyte beta receptors eluted from FV-104 monoclonal antibody affinity columns with Na-DodSO4 appeared as three components of Mr 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 (Mr, 70,000), indicating that the turkey erythrocyte beta 1 receptor can be purified to homogeneity.