*3.9. E*ff*ect of Metal Ions and Chelating Agents*

The influence of divalent metal ions on CamPhoD was determined using the standard method for determining the alkaline phosphatase activity, with the addition of Mg2+, Ca2+, Mn2+, Zn2+, Co2+, Ni2+, Cu2+, Cs2+, Fe3<sup>+</sup> ions, EDTA, and EGTA at a concentration of 2 mM to the incubation mixture. The incubation mixture without cations and chelating agents was used as a control.

#### *3.10. E*ff*ect of NaCl and KCl*

The effects of Na<sup>+</sup> and K<sup>+</sup> were investigated by adding NaCl and KCl to a standard incubation mixture at a concentration of 0–1.5 M. The alkaline phosphatase activity was determined as described above.
