Mammalian beta 1- and beta 2-adrenergic receptors. Immunological and structural comparisons.
Beta 1- and beta 2-adrenergic receptors, pharmacologically distinct proteins, have been reported to be structurally dissimilar. In the present study three techniques were employed to compare the nature of mammalian beta 1- and beta 2-adrenergic receptors. Antibodies against each of the receptor subtypes were raised separately. Polyclonal antisera against beta 1-receptors of rat fat cells were raised in mice, and antisera against beta 2-receptors of guinea pig lung were raised in rabbits. Receptors purified from rat fat cells (beta 1-), S49 mouse lymphoma cells (beta 2-), and rat liver (beta 2-) were probed with these antisera. Each anti-receptor antisera demonstrated the ability to immunoprecipitate purified receptors of both beta 1- and beta 2- subtypes. The mobility of beta-receptors subjected to polyacrylamide gel electrophoresis was probed using antireceptor antibodies and nitrocellulose blots of the gels. Fat cell beta 1-adrenergic receptors display Mr = 67,000 under reducing conditions and Mr = 54,000 under nonreducing conditions, as previously reported (Moxham, C. P., and Malbon, C. C. (1985) Biochemistry 24, 6072-6077). Both beta 1- and beta 2-receptors displayed this same shift in electrophoretic mobility observed in the presence as compared to the absence of disulfide bridge-reducing agents, as detected both by autoradiography of the radiolabeled receptors and by immunoblotting of native receptors. Finally, isoelectric focusing of purified radioiodinated beta 1- and beta 2-adrenergic receptors revealed identical isoelectric points. These data are the first to provide analyses of immunological, structural, and biochemical features of beta 1- and beta 2-subtypes in tandem and underscore the structural similarities that exist between these pharmacologically distinct receptors.
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D000936:Antigen-Antibody Complex; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007106:Immune Sera; D008099:Liver / Q000378:metabolism*; D008223:Lymphoma / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D013045:Species Specificity; D014018:Tissue Distribution
D000936:Antigen-Antibody Complex; D007106:Immune Sera; D011943:Receptors, Adrenergic, beta