title: [Interaction of Pb(II) ions with C-phycocyanin from Spirulina platensis: effect of ionic strength].
abstract: The effect of Pb(II) ions on C-phycocyanin from Spirulina platensis was studied by the method of fluorescence spectroscopy. The efficiency of quenching was analyzed using the Stern-Volmer relation. Isotherms of adsorption were constructed, and the constants of binding of Pb(II) ions to C-phycocyanin in solutions of varying ionic strength were determined by equilibrium dialysis and atomic absorption spectroscopy. The constants of binding of Pb(II) ions to C-phycocyanin in 2, 20, and 50 mM NaN03 solutions were estimated to be 4.79 x 10(5), 3.63 x 10(5) and 2.82 x 10(5), respectively. It was found that the interaction of Pb(II) ions with C-phycocyanin has a cooperative character at all values of ionic strengths studied.
mesh_terms: D002413:Cations, Divalent; D000458:Cyanobacteria / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D009994:Osmolar Concentration; D010798:Phycocyanin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D002413:Cations, Divalent; D010798:Phycocyanin; D007854:Lead