Modulation of calcitonin binding by calcium: differential effects of divalent cations.
J Recept Res
; 13(8): 1173-97, 1993.
Article
en En
| MEDLINE
| ID: mdl-8254582
ABSTRACT
Binding of salmon calcitonin to bovine hypothalamic membranes is enhanced about 25% by calcium with a half-maximal effect at 15 mM calcium. In contrast, membranes prepared from a cell line expressing a recombinant human calcitonin receptor show no effect of calcium under similar conditions. The hypothalamic calcitonin receptor solubilized with CHAPS detergent retains an apparent Kd of 0.3 nM for salmon calcitonin; however, binding of calcitonin to the detergent-solubilized receptor complex can be inhibited by divalent cations in order of potency Mn > Ca approximately Sr approximately Mg >> NaCl with Mn and Ca having apparent Ki's of 5 mM and 20 mM respectively. Dixon and Scatchard plots of Mn and Ca inhibition of binding to the soluble receptor complex suggest a noncompetitive mechanism of inhibition. Calcium also inhibits calcitonin binding to a detergent-solubilized recombinant human calcitonin receptor. Inhibition of calcitonin binding is observed using two independent methods for determining soluble receptor-hormone complex and inhibition is reversed by EDTA.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Calcitonina
/
Calcio
/
Receptores de Calcitonina
Límite:
Animals
Idioma:
En
Revista:
J Recept Res
Año:
1993
Tipo del documento:
Article