The Thermodynamic and pH Metric Binding Studies of Cu+2 Ions with Egg Protein by Spectrometric and Diffusion Current Techniques

Abstract

Abstract Transition metals have unique efficacy in catalyzing various industrial reactions and also in living system, the redox reaction and redox changes in the metal ions catalyzed valence changes in the substrate molecule. The survey of the existing literature revealed that the binding of Molybdenum, Vanadium, Zinc, Cadmium, Copper, Nickel and Cobalt with the protein is well known but no binding studies of copper metal with egg protein are reported. With a view to extend the existing knowledge of ecological nature of metal-protein system, it was thought of interest to investigate the properties of metal-protein mixture. Investigations on the aspects of these binding problems were planned and their bindings constants have been determined using suitable physico-chemical methods. The pH metric, diffusion current measurements, spectrophotometric methods have been used on the binding of copper ions with albumin. The effect of physico-chemical factors on interaction between divalent metal ion i.e. copper with albumin has been discussed. On the basis of observed results, it is found that the binding data were dependent on pH and temperature. From scatchard plots, the intrinsic association constants (k) and the number of binding sites (n) were calculated and found high at lower pH and temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with copper (II) ions. The enthalpy (ΔH), entropy (ΔS) changes, free energy change (ΔG°) have been calculated.