Marquèze B, Seagar M J, Couraud F
Laboratoire de Biochimie, Centre National de la Recherche Scientifique Unité Associée 1179, Marseille-France.
Eur J Biochem. 1987 Dec 1;169(2):295-8. doi: 10.1111/j.1432-1033.1987.tb13611.x.
High-affinity binding sites for mono[125I]iodoapamin were detected in membranes (Kd = 59 pM, Bmax = 24 fmol/mg protein) and cultured cells (Kd = 69 pM, Bmax = 2.8 fmol/mg protein) from rat heart and in membranes from guinea-pig ileum (Kd = 67 pM, Bmax 42 fmol/mg protein) and liver (Kd = 15 pM, Bmax = 43 fmol/mg protein). Binding was stimulated by K+ ions (K0.5 = 0.3-0.5 mM). Covalent labeling with arylazide [125I]iodoapamin derivatives showed that smooth muscle, liver and heart binding molecules are associated with a 85-87-kDa polypeptide. A second strongly labeled 57-kDa component was identified in liver membranes only.
