Ca2+
activates both transfructosylation and hydrolytic activities
Ca2+
activates, recombinant enzyme
Ca2+
Ca2+ play an important structural role. At 45°C the mutant enzymes D500A and D500N are inactive in the absence of Ca2+ ions, with, respectively, 15% and 45% of wild-type activity remaining in the presence of 1 mM Ca2+. In the presence of 1 mM Ca2+ mutant enzymes display highest activity at 40°C. In the absence of Ca2+ ions, the optimal temperature is 30°C; stimulates activity, Asp500 residues play an important role in Ca2+ binding
Ca2+
dependent on for tertiary structure, can partially be replaced by Sr2+, not Mg2+, Sr2+, Ba2+, and Mn2+
Ca2+
Mg2+, Zn2+, Mn2+, Fe2+ have no effect
Co2+
activates strongly, recombinant enzyme
Fe2+
4fold increase in activity at 5 mM
Fe3+
dependent on for tertiary structure, can partially be replaced by Sr2+, not Mg2+, Ba2+, and Mn2+
Mg2+
activates both transfructosylation and hydrolytic activities