A point mutation in the seventh hydrophobic domain of the alpha 2 adrenergic receptor increases its affinity for a family of beta receptor antagonists.
Article Details
- CitationCopy to clipboard
Suryanarayana S, Daunt DA, Von Zastrow M, Kobilka BK
A point mutation in the seventh hydrophobic domain of the alpha 2 adrenergic receptor increases its affinity for a family of beta receptor antagonists.
J Biol Chem. 1991 Aug 15;266(23):15488-92.
- PubMed ID
- 1678390 [ View in PubMed]
- Abstract
Previous studies have shown that differences in subtype-specific ligand binding between alpha 2 and beta 2 adrenergic receptors are largely determined by the seventh hydrophobic domain. Here, we report that a single amino acid substitution (Phe412----Asn) in the seventh hydrophobic domain of the alpha 2 adrenergic receptor reduces affinity for the alpha 2 antagonist yohimbine by 350-fold and increases affinity for beta antagonist alprenolol by 3000-fold. The affinity of this mutant receptor alpha 2F----N for several alpha and beta adrenergic receptor agonists and antagonists was determined. Beta adrenergic receptor antagonists containing an oxygen atom linking the amino side chain with the aromatic ring bound to alpha 2F----N with high affinity, while the beta receptor antagonist sotalol, which lacks this oxygen, bound with low affinity. These data suggest that the Asn residue is involved in conferring specificity for binding to a specific class of beta receptor antagonists.