High affinity interaction of endothelin-3 with recombinant ETA receptors
| Autor: | Julien Desmarets, Christian Frelin |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Endothelin Receptor Antagonists
Indoles Stereochemistry Eta receptor Biophysics Viper Venoms Ligands Transfection Biochemistry Binding Competitive Peptides Cyclic law.invention Cell Line law Animals Protein Isoforms Binding site education Receptor Molecular Biology Etb receptor Volume concentration education.field_of_study Endothelin-3 Endothelin-1 Chemistry Receptors Endothelin Endothelins Cell Membrane Cell Biology Azepines Receptor Endothelin A Receptor Endothelin B Peptide Fragments Recombinant Proteins Endothelin 3 Rats Kinetics Sarafotoxin S6c Recombinant DNA Tyrosine Cattle |
| Zdroj: | Biochemical and biophysical research communications. 256(2) |
| ISSN: | 0006-291X |
| Popis: | Pharmacological evidence has suggested that endothelin-3 (ET-3) may act via a novel form of ET receptor that is shared by ETA receptor antagonists but not by ETB receptor selective agonists. This study analyses the properties of interaction of ET-3 with recombinant bovine ETA receptor. Apparent Kd(ET-3) values as low as 50 nM were defined from [125I]ET-1 binding experiments performed at low (5 μg/ml) protein concentrations in the assays. Larger (up to 1 μM) values were artefactually obtained in experiments performed at larger protein concentrations. The three monoiodo ET-3 derivatives were synthetized. ([125I]Y14)ET-3 did not recognize ETA receptors. ([125I]Y6)ET-3 labelled 18% of [125I]ET-1 binding sites with a Kd value of 320 pM. ([125I]Y13)ET-3 labelled 44% of [125I]ET-1 binding sites with a Kd value of 130 pM. High affinity ([125I]Y6)ET-3 and ([125I]Y13)ET-3 bindings were prevented by ET-1 (Kd = 5-7 pM), ET-3 (Kd = 70-250 pM), BQ-123 (Kd = 2 nM) and FR139317 (Kd = 2 nM) but not by low concentrations of 4-AlaET-1, sarafotoxin S6c or IRL1620. The three monoiodo ET-3 derivatives bound to recombinant rat ETB receptors with a pM affinity. The results suggest that ET-3, ([125I]Y6)ET-3 and ([125I]Y13)ET-3 should not be considered as ETB receptor specific ligands. |
| Databáze: | OpenAIRE |
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