title: Study of interaction between agonists and asn293 in helix VI of human beta(2)-adrenergic receptor.
abstract: Previously, we demonstrated the involvement of Asn293 in helix VI of the human beta(2)-adrenergic receptor in stereoselective agonist recognition and activation. In the present study, we have further explored the role of this residue by synthesizing derivatives of isoproterenol and clenbuterol, two beta-adrenergic receptor agonists. We analyzed their efficacy and affinity on the wild-type and a mutant receptor (Asn293Leu). Each compound had similar efficacy (tau values) on both the wild-type and mutant receptor, although tau values varied considerably among the eight compounds studied. It appeared that one derivative of isoproterenol, but not of clenbuterol, showed a gain in affinity from the wild type to the mutant receptor. This derivative had a methyl substituent instead of the usual beta-OH group in the aliphatic side chain of isoproterenol, compatible with the more lipophilic nature of the leucine side chain. Such a "gain of function" approach through a combination of synthetic chemistry with molecular biology, may be useful to enhance our insight into the precise atomic events that govern ligand-receptor interactions.
authors.affiliation: Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Leiden, The Netherlands.
authors.forename: H M
authors.initials: HM
authors.lastname: Zuurmond
authors.forename: J
authors.initials: J
authors.lastname: Hessling
authors.forename: K
authors.initials: K
authors.lastname: Blüml
authors.forename: M
authors.initials: M
authors.lastname: Lohse
authors.forename: A P
authors.initials: AP
authors.lastname: Ijzerman
mesh_terms: D000318:Adrenergic beta-Agonists / Q000138:chemical synthesis / Q000494:pharmacology*; D000818:Animals; D001216:Asparagine / Q000378:metabolism*; D001667:Binding, Competitive; D016466:CHO Cells; D002976:Clenbuterol / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000494:pharmacology; D006224:Cricetinae; D006801:Humans; D007545:Isoproterenol / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000494:pharmacology; D008024:Ligands; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D018343:Receptors, Adrenergic, beta-2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000318:Adrenergic beta-Agonists; D008024:Ligands; D018343:Receptors, Adrenergic, beta-2; D001216:Asparagine; D007545:Isoproterenol; D002976:Clenbuterol