Photoaffinity labeling of the beta-adrenergic receptor in synaptic membranes of rat cerebral cortex and cerebellum.

The beta-adrenergic receptor polypeptides in synaptic membranes of rat cerebral cortex and cerebellum have been identified using the photoaffinity label [125I]iodoazidobenzylpindolol. The major receptor polypeptides possess apparent molecular weights of 62,000 and 49,000 (cerebral cortex) or 59,000 and 46,000 (cerebellum). Treatment of the membranes with endoglycosidase F caused the receptor polypeptides from both tissues to exhibit lower apparent molecular weight (51,000) on sodium dodecyl sulfate polyacrylamide gels, indicating that beta-adrenergic receptors in mammalian brain are glycoproteins as are the receptors in peripheral tissues.