Binding of magnesium ions

The average binding of magnesium ions NH is given by the following partial derivatives of the binding polynomial ... 

Figure 1.5 shows a plot of JVMg versus pMg at several values of pH. As the hydrogen ion concentration is increased, the binding of magnesium ions is decreased because of the competition for the same sites. 

In thermodynamics, this is referred to as a Maxwell equation. This equation is derived later in Section 4.8. Thus the effect of pMg on the binding of hydrogen ions is the same as the effect of pH on the binding of magnesium ions in short, these are reciprocal effects. The bindings of these two ions are referred to as linked functions. Equation 1.3-17 can be confirmed by plotting these two derivatives, and the same plot is obtained in both cases. This would be a lot of work to do by hand, but since Mathematical can take partial derivatives, this can be done readily with a computer. The two plots are identical and are given in Fig. 1.8. 

Since JVH and NMg can be calculated for these reactants, ArJVH and Ar/VMg can be calculated as a function of pH and pMg. However, when a computer is available there is an easier way to do this by using equation 1.3-13 for the binding of hydrogen ions and 1.3-14 for the binding of magnesium ions. For example, equation 1.5-1 can be written... 

Figure 1.12 shows the change in binding of magnesium ions as a function of pH and pMg. Magnesium ions are always produced in the hydrolysis because... 

Figure 1.12 Change in the binding of magnesium ions in the hydrolysis of ATP at 298.15 K and 0.25 M ionic strength (see Problem 1.9).

Calculation of the Change in Binding of Magnesium Ions in a Biochemical Reaction... 

CALCULATION OF THE CHANGE IN BINDING OF MAGNESIUM IONS IN A BIOCHEMICAL REACTION... 

The equations for the average number of magnesium ions bound by a reactant NMg and the change in binding of magnesium ions in a reaction ArNMg follow the development of the preceding section ... 

The change in binding of magnesium ions in a biochemical reaction can also be calculated from the acid dissociation and magnesium complex ion dissociation constants using... 

Average Binding of Magnesium Ions by ATP as a Function of pH and pMg and Linked Functions... 

In electrostatic interactions the potentially destabilizing force of the phosphate group charges (repulsion between nearby negative charges) is offset by the binding of magnesium ions and polycationic molecules such as the polyamines and histones. 

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