Ion binding, in solution

Scott, J. E. (1968). Ion binding in solutions containing acid mucopolysaccharides. 

L Kotin, M Nagasawa. Chain model for polyelectrolytes. VII. Potentiometric titration and ion binding in solutions of linear polyelectrolytes. J Chem Phys 36 873-879, 1962. 

Lindman, B. Applications of nuclear quadrupole relaxation to the study of ion binding in solution. Thesis, Lund 1971... 

Since binding in solution results from a compromise between interaction with the ligand and solvation, new insights into the origin of the cation recognition process and of the macrocyclic and cryptate effects can be gained from experimental gas phase studies [2.34, 2.35] as well as from computer modelling calculations in vacuo or in a solvent [1.35b, 1.42, 1.43, 1.45, 2.36, 2.37, A.37]. In particular, molecular dynamics calculations indicate that complementarity is reflected in restricted motion of the ion in the cavity [1.45, 2.36]. 

Figure 15.19. Calcium Indicator. The fluorescence spectra of the calcium-binding dye Fura-2 can be used to measure available calcium ion concentrations in solution and in cells. [After S. J. Lippard and J. M. Berg, Principles of Bioinorganic Chemistry. (University Science Books, 1994), p. 193.]...

After defining aquatic equilibrium equations for the two component system, the total concentration of metal ion added to solution and the fluorescence intensity modifications must be related to the conditional stability constants (Kj and and the concentrations of metal ion binding FA sites (0 and CjJ. Using equations 14 and 17 it is possible to relate the concentration of complex at site one to its conditional stability constant, site concentration and to the free metal ion existing in solution. This relationship is shown in equation 19. 

The maximal binding capacity was determined at certain pH values, using both batch and column methods. In the batch methods, the total amount of the metal salt was always in 2-3 fold excess over the theoretical ion capacity, and the metal uptake by the polymers was calculated from the dif-ference.s in metal concentration prior and after the equilibration. In the column method. 500 1000 ml of 0.1- 0.5 M metal sulphate solution was passed through a 10 50 g polymer in a column at a rate of 1 ml/min. Tractions were collected until the initial ion concentration was achieved. The metal uptake was calculated again from the total amount of metal ions recovered in solution, by difference. 

Trace amounts of reduced transition metal ions such as iron and copper are known to generate hydroxyl radicals resulting in oxidized nucleotide bases and strand breaks by means of Fenton-type reactions [11-15]. Diethylenetriaminepentaacetic acid (DTPA) and ethylenediamine tetraacetic acid (EDTA) are compounds that chelate metal ions present in solution or bound to macromolecules. These chelators have also been shown to inhibit DNA degradation via DNase by binding various divalent cations (e.g., Mg +) necessary for enzymatic activity [16]. 

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