4.2.1.111 Ca2+ the activity increases by around 2fold in the presence of 10 mM CaCl2 4.2.1.111 CaCl2 requirement of alkaline earth metal ion for activity. 10 mM, around 2fold increase in activity 4.2.1.111 Mg2+ the activity increases by around 2fold in the presence of 25 mM MgCl2 4.2.1.111 MgCl2 requirement of alkaline earth metal ion for activity. 25 mM, around 2fold increase in activity 4.2.1.111 Na+ the activity increases by around 2fold in the presence of 0.1 M NaCl 4.2.1.111 NaCl 0.1 mM, around 2fold increase in activity