Mutations inducing divergent shifts of constitutive activity reveal different modes of binding among catecholamine analogues to the beta(2)-adrenergic receptor.

Détails

ID Serval
serval:BIB_62417A1FBB9B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Mutations inducing divergent shifts of constitutive activity reveal different modes of binding among catecholamine analogues to the beta(2)-adrenergic receptor.
Périodique
British Journal of Pharmacology
Auteur(s)
Del Carmine R., Ambrosio C., Sbraccia M., Cotecchia S., Ijzerman A.P., Costa T.
ISSN
0007-1188 (Print)
ISSN-L
0007-1188
Statut éditorial
Publié
Date de publication
2002
Volume
135
Numéro
7
Pages
1715-1722
Langue
anglais
Résumé
1. We compared the changes in binding energy generated by two mutations that shift in divergent directions the constitutive activity of the human beta(2) adrenergic receptor (beta(2)AR). 2. A constitutively activating mutant (CAM) and the double alanine replacement (AA mutant) of catechol-binding serines (S204A, S207A) in helix 5 were stably expressed in CHO cell lines, and used to measure the binding affinities of more than 40 adrenergic ligands. Moreover, the efficacy of the same group of compounds was determined as intrinsic activity for maximal adenylyl cyclase stimulation in wild-type beta(2)AR. 3. Although the two mutations had opposite effects on ligand affinity, the extents of change were in both cases largely correlated with the degree of ligand efficacy. This was particularly evident if the extra loss of binding energy due to hydrogen bond deletion in the AA mutant was taken into account. Thus the data demonstrate that there is an overall linkage between the configuration of the binding pocket and the intrinsic equilibrium between active and inactive receptor forms. 4. We also found that AA mutation-induced affinity changes for catecholamine congeners gradually lacking ethanolamine substituents were linearly correlated to the loss of affinity that such modifications of the ligand cause for wild-type receptor. This indicates that the strength of bonds between catechol ring and helix 5 is critically dependent on the rest of interactions of the beta-ethanolamine tail with other residues of the beta(2)-AR binding pocket.
Mots-clé
Animals, Binding Sites, CHO Cells, Catecholamines/chemistry, Catecholamines/pharmacology, Cricetinae, Mutation, Receptors, Adrenergic, beta-2/drug effects, Receptors, Adrenergic, beta-2/genetics, Structure-Activity Relationship
Pubmed
Web of science
Création de la notice
24/01/2008 11:05
Dernière modification de la notice
20/08/2019 14:19
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