An agonist-like monoclonal antibody against the human β2-adrenoceptor
| Autor: | J Hoebeke, Alfredo Mijares, Diane Lebesgue, Gerd Wallukat, J Argibay, Claude Granier |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Patch-Clamp Techniques
medicine.drug_class Trypanosoma cruzi Molecular Sequence Data Peptide Monoclonal antibody Epitope Membrane Potentials Immunoenzyme Techniques Epitopes Mice Radioligand Assay Heart Rate Tumor Cells Cultured medicine Extracellular Animals Humans Amino Acid Sequence Receptor Adrenergic beta-2 Receptor Agonists Peptide sequence Pharmacology chemistry.chemical_classification biology Myocardium Antibodies Monoclonal Adrenergic beta-Agonists Molecular biology Epitope mapping Biochemistry chemistry Fluorescent Antibody Technique Direct biology.protein Antibody |
| Zdroj: | European Journal of Pharmacology. 348:123-133 |
| ISSN: | 0014-2999 |
| Popis: | Monoclonal antibodies were produced against a peptide corresponding to the second extracellular loop of the human beta2-adrenoceptor. One of these monoclonals, inducing an agonist-like effect in neonatal rat cardiomyocytes, was used to define the structural and physiological basis of this activity. The epitope recognized by the antibody corresponds to the sequence Trp-Tyr-Arg-Ala-Thr-His-Gln-Glu as determined by peptide scanning. Analysis by alanine modification of the peptide epitope showed the importance of the Trp, and Glu residues in antibody recognition The apparent affinity of the antibody assessed either by surface plasmon resonance or by functional titration on its agonist-like activity showed a similar value (10(8) M(-1)). The antibody recognized the receptor in its native form as shown by immunofluorescence experiments on A431 cells but not in its denatured form as shown by its absence of staining in immunoblots. The positive chronotropic effect in vitro was specifically blocked by both the antigenic peptide and the specific beta2-antagonist (+/-)-1-[2,3-(Dihydro-7-methyl1H-inden-4-yl)oxy]-3-[(1-methy lethyl)amino]-2-butanol hydrochloride (ICI1118,551). This activity was mediated through activation of Ca2+ L-type channels as assessed in guinea pig cardiomyocytes. These results suggest that the epitope is located in an extracellular alpha-helix, whose recognition by the antibody could stabilize the receptor in its 'active' conformation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect