title: Specific nonpeptide photoprobes as tools for the structural study of the angiotensin II AT(1) receptor.
abstract: The aim of this work was to obtain photoactivatable nonpeptide antagonists of the angiotensin II AT(1) receptor. Based on structure-function relationships, two chemical structures as well as appropriate synthetic schemes were chosen as a frame for the design of radiolabeled azido probes. The feasibility of the strategy was first assessed by the synthesis of two tritiated ligands 21 and 22 possessing a high affinity for the AT(1) receptor and a low nonspecific binding to membrane or cell preparations. We then prepared two unlabeled azido derivatives 7 and 14 which retained a fairly high affinity for the AT(1) receptor. The latter compound proved to be suitable for receptor irreversible labeling and was prepared in its tritiated form 28. This tritiated azido nonpeptide probe displayed a K(d) value of 11.8 nM and a low nonspecific binding. It was suitable for specific and efficient covalent labeling of the recombinant AT(1A) receptor stably expressed in CHO cells. The electrophoretic pattern of the specifically labeled entity was strictly identical to that of purified receptor photolabeled with a biotinylated peptidic photoactivatable probe. This new tool should be useful for the mapping of the nonpeptide receptor binding site. These potential applications are discussed in light of the current knowledge of molecular mechanisms of G-protein coupled receptor activation and inactivation.
authors.affiliation: Laboratoires Fournier S.A., 50 Rue de Dijon, 21121 Daix, France.
authors.forename: S
authors.initials: S
authors.lastname: Nouet
authors.forename: P R
authors.initials: PR
authors.lastname: Dodey
authors.forename: M R
authors.initials: MR
authors.lastname: Bondoux
authors.forename: D
authors.initials: D
authors.lastname: Pruneau
authors.forename: J M
authors.initials: JM
authors.lastname: Luccarini
authors.forename: T
authors.initials: T
authors.lastname: Groblewski
authors.forename: R
authors.initials: R
authors.lastname: Larguier
authors.forename: C
authors.initials: C
authors.lastname: Lombard
authors.forename: J
authors.initials: J
authors.lastname: Marie
authors.forename: P P
authors.initials: PP
authors.lastname: Renaut
authors.forename: G
authors.initials: G
authors.lastname: Leclerc
authors.forename: J C
authors.initials: JC
authors.lastname: Bonnafous
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D001386:Azides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001565:Benzoates / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D016466:CHO Cells; D006224:Cricetinae; D066298:In Vitro Techniques; D008024:Ligands; D008099:Liver / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009154:Mutation; D019920:Photoaffinity Labels / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000235:genetics / Q000378:metabolism; D014316:Tritium
chemical_list: C401385:2-(((2-butyl-1-((4-carboxyphenyl)-methyl)-1H-imidazol-5-yl)methyl)amino)-4-azidobenzoic acid; D057911:Angiotensin Receptor Antagonists; D001386:Azides; D001565:Benzoates; D008024:Ligands; D019920:Photoaffinity Labels; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D014316:Tritium; D000804:Angiotensin II