title: [Characteristics of ceruloplasmin interaction with a specific receptor of human erythrocytes].
abstract: The equilibrium binding of ([125I]ceruloplasmin) ([125I]CP) to a specific receptor of human erythrocytes was investigated. It was shown that reaching the binding equilibrium is a slow process. A strong dependence of binding on Ca2+ concentration (from 0.1 to 1 mM) was revealed; the optimal values were achieved at millimolar concentrations of Ca2+.Mg2+ do not affect the binding of [125I]CP. Under conditions of optimal binding (0.01 M Tris-HCl buffer pH 7.4 containing 158 mM NaCl and 1 mM Ca2+, 4 degrees C), the values of constants for [125I]CP binding to intact erythrocytes (Kd = 1.0 nm) and to membrane fragments (Kd = 0.8 nM) as well as the number of binding sites (16.3 X 10(-15) mol per 40,000,000 erythrocytes) were determined. No ceruloplasmin transport across the erythrocyte membrane was observed. This finding and the similarity of Kd values for ceruloplasmin binding to membrane fragments and to intact erythrocytes indicate that the effect of ceruloplasmin on human erythrocytes is due to the protein molecule interaction with membrane receptors.
authors.forename: E L
authors.initials: EL
authors.lastname: Saenko
authors.forename: V V
authors.initials: VV
authors.lastname: Basevich
authors.forename: A I
authors.initials: AI
authors.lastname: Iaropolov
mesh_terms: D001692:Biological Transport; D002118:Calcium / Q000494:pharmacology; D002570:Ceruloplasmin / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011971:Receptors, Immunologic; D018000:Receptors, Peptide
chemical_list: D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D018000:Receptors, Peptide; C040519:ceruloplasmin receptor; D002570:Ceruloplasmin; D008274:Magnesium; D002118:Calcium
vernacular_title: Osobennosti vzaimodeĭstviia tseruloplazmina so spetsificheskim retseptorom éritrotsitov cheloveka.