Selective Ion-Binding by Protein

Ion binding is essential for a variety of physiological processes. The binding of calcium ions by some protein triggers the process to induce the muscle contraction and enzymatic reactions [40,41], The initial process of the information 

The results in general show fair agreement with the experimental results. Particularly, the theory discriminates the divalent ion from the monovalent ions quite well. Apparently, the concentration dependence of the two monovalent ions is not resolved well. This may be due to the potential parameters for the ions. However, it will not seriously influence the results for the ion recognition by protein, because the process is determined primarily by the free energy difference of the same ion inside protein and in bulk solutions. 

The 3D-RISM calculation was carried out for aqueous solutions of three different electrolytes, CaCp, NaCl, and KC1, and for four different mutants of the protein, wild type, Q86D, A92D, Q86D/A92D that have been studied experimentally by Kuroki and Yutani [46]. 

The A92D mutant in the NaCl solution shows a conspicuous distribution of a Na+ ion bound at the recognition site, which is in accord with the 

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