Abstract
The stereospecificity of the β-adrenergic receptor of turkey erythrocyte ghosts was studied. Binding of the specific β-adrenergic antagonist, propranolol, was found to occur exclusively with the l-stereoisomer. The stereospecificity of catecholamine binding was determined by assaying the ability of the catecholamines to displace [3H]propranolol. Binding of the catecholamines was also found to be stereospecific for the l-stereoisomers. Furthermore, the d-stereoisomers do not compete with the l form for binding. Using this displacement technique, we were able to calculate the dissociation constants for l-epinephrine, l-norepinephrine, and l-isoproterenol from the β-receptor and compare these values to the apparent dissociation constants obtained from the direct activation of adenylate cyclase (EC 4.6.1.1) by these catecholamines.
Keywords: stereospecificity, erythrocyte
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Selected References
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