The receptors for endothelins and their analogues in SK-N-MC neuroblastoma cells.
The potency order of peptides to inhibit [125I]endothelin-1 binding and to stimulate phosphatidylinositol phosphate (PtdInsP) turnover in SK-N-MC cells was consistent with the presence of ETA-endothelin receptors. Divalent cations enhanced [125I]endothelin-1 binding by, in the case of Mn2+, increasing radioligand affinity. Mn2+ did not induce conformational changes in endothelin-1, and its effect was maintained in solubilized receptors. Hence, metal ions may directly interact with endothelin receptors. The effects of BQ-123 and [Ala1,3,11,15]endothelin-1 on PtdInsP turnover were investigated. Concentration-response curves of endothelins were modeled by a second-order equation that assumes pseudoirreversible ligand binding.
Huggins
J P
JP
Marion Merrell Dow Research Institute, Strasbourg, France.
Pelton
J T
JT
van Giersbergen
P L
PL
D001667:Binding, Competitive / Q000502:physiology; D002412:Cations / Q000494:pharmacology; D003627:Data Interpretation, Statistical; D003902:Detergents; D009447:Neuroblastoma / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D011487:Protein Conformation; D011869:Radioligand Assay; D017466:Receptors, Endothelin / Q000378:metabolism*; D012995:Solubility; D014407:Tumor Cells, Cultured
D002412:Cations; D003902:Detergents; D018129:Phosphatidylinositol Phosphates; D017466:Receptors, Endothelin