Ion binding, and

The setting of AB cements is an example of gelation, and gelation is related to ion binding. A theoretical examination of the various phenomena associated with ion binding and gelation finds its clearest exposition in the field of polyelectrolytes. Moreover, this field may be wider than it seems at first. 

Harris, F. E. Rice, S. A. (1957). A model for ion binding and exchange in polyelectrolyte solutions and gels. Journal of Physical Chemistry, 58, 725-32. 

Michaeli, I. (1960). Ion-binding and the formation of insoluble polymethacrylic salts. Journal of Polymer Science, 48, 291-9. 

Cevc, G. Watts, A. Marsh, D., Titration of the phase transition of phosphatidylserine bilayer membranes. Effects of pH, surface electrostatics, ion binding, and head group hydration. Biochemistry 20, 4955 -965 (1981). 

Reactions of hydrophilic anions in microemulsions can be treated in terms of the ion-exchange formalism. The extent of ion binding to microemulsion droplets has been estimated conductimetrically, and the rates of reactions of OH- and F with p-nitrophenyl diphenyl phosphate are consistent with the extent of ion binding and competition between reactive and inert anions. Alternatively the data could be accommodated to variations in the estimated surface potential of the droplet (Mackay and Hermansky, 1981 Mackay, 1982). 

Ponce, J., Biton, B Benavides, J., Avenet, P, and Aragon, C. (2000) Transmembrane domain III plays an important role in ion binding and permeation in the glycine transporter GLYT2. J. Biol. Chem. 275, 13856-13862. 

However, it should be noted that the greater flexibility potentially obtainable in ion mediated systems with respect to modulation of the energies of their CT states, is not obtainable with substituted systems. In the former case, changes in ion concentration of the solution containing the ion-modulated system directly affect ion binding, and thus the... 

In both schemes, the specificities of the pump for catalysis change in the two enzyme states. Jencks points out that coupling is determined (a) by the chemical specificity achieved in catalyzing phosphoryl transfer to and from the enzyme (wherein E-Ca2 reversibly binds ATP, and E reacts reversibly with orthophosphate), and (b) by the vectorial specificity for ion binding and dissociation (wherein E reversibly binds/dissociates cytoplasmic calcium ion, and E—P reversibly binds/dissociates luminal calcium). There must be a single conformation change during the reaction cycle between Ei and E2 in the free enzyme and from Ei P-Ca2 to E2-P-Ca2 after enzyme phosphorylation. 

Szebenyi, D. M. E., and Moffat, K. (1986). The refined structure of vitamin D-dependent calcium-binding protein from bovine intestine. Molecular details, ion binding, and implications for the structure of other calcium-binding proteins./. Biol. Chem. 261, 8761-8777. 

Quantification of metal ion binding and the determination of the nature of the binding sites are extremely difficult for humic acid because of its polymeric (molar masses ca. 5 x 104) and heterogeneous nature. The results of such attempts are often contradictory.15,16 Frequently a 1 1 metal humic acid ratio is assumed for the complexes, a very surprising assumption for such large molecules with high concentrations of carboxylic acids. There is evidence for other stoichiometries, including... 

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