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.
Subject(s)
Cyanobacteria/chemistry , Lead/chemistry , Phycocyanin/chemistry , Cations, Divalent , Osmolar Concentration , Spectrometry, FluorescenceABSTRACT
The energetics of Pb(II) ion binding to DNA was determined from their binding isotherms by equilibrium dialysis and atomic absorption spectroscopy at different ionic strengths. Two types of binding of Pb(II) ions to DNA at different NaCl concentrations were observed.
Subject(s)
DNA/chemistry , Lead/chemistry , Nitrates/chemistry , Algorithms , Animals , Cations, Divalent , Cattle , Osmolar Concentration , Spectrophotometry, Atomic , Spleen/chemistryABSTRACT
The energetics of Cu (II) ion binding to mononucleosomes from C3HA mice liver and ascitic hepatoma 22A cells was determined from their binding isotherms by equilibrium dialysis and pulse high frequency inductively coupled plasma atomic emission spectroscopy. Anticooperative binding of copper ions with normal and tumor mononucleosomes were observed under various NaCl concentrations (0.002; 0.02; 0.2 M). The binding constants of Cu(II) ion with normal mononucleosomes in 0.002, 0.02, 0.2 M NaCl are 6.10 x 10(4), 5.22 x 10(4), 4.31 x 10(4) respectively. The binding constants of Cu(II) ion with tumor mononucleosomes in 0.002, 0.02, 0.2 M NaCl are 6.68 x 10(4), 6.12 x 10(4), 4.82 x 10(4) respectively.
