3.6.1.11 Ca2+ in the presence of Ca2+, the activity is about 20% of levels with Mg2+ 712478 3.6.1.11 Cd2+ stimulated in the micromolar range to a lower extent than Cu2+ and Mn2+ 725894 3.6.1.11 Co2+ 0.1 mM Co2+, PPX activity is stimulated by a factor of two in the nuclear fraction, but not in the mitochondrial fraction 697460 3.6.1.11 Co2+ 0.1 mM, 31fold activity enhancement 654784 3.6.1.11 Co2+ 0.1 mM, 6fold activity stimulation 654785 3.6.1.11 Co2+ 2 mM CoCl2, 2.5fold stimulation 209847 3.6.1.11 Co2+ 2.5fold activation 690206 3.6.1.11 Co2+ 5 mM, 108% of the activation by Mg2+ 209846 3.6.1.11 Co2+ 6fold activation at 0.1 mM 654785 3.6.1.11 Co2+ activates 687628, 756231 3.6.1.11 Co2+ activates 4.4fold polyphosphatase II and activates 1.5fold polyphosphatase I both at 0.15 mM 657203 3.6.1.11 Co2+ best activator 654784 3.6.1.11 Co2+ best activator, maximum activation at 0.1 mM 734338 3.6.1.11 Co2+ Co2+ stimulates phosphate release from the polyphosphate chain end 735010 3.6.1.11 Co2+ divalent cation required, order of decreasing stimulation: Co2+, Mn2+, Mg2+, Ni2+ 209852 3.6.1.11 Co2+ KD: 46.9 +/- 5.66 micorM Co2+ with p-nitrophenyl phosphate, KD: 10.7 +/- 1.07 microM Co2+ with 5'-AMP 656266 3.6.1.11 Co2+ little effect on polyP15 hydrolysis 656105 3.6.1.11 Co2+ Mn2+ or Co2+ required. Mg2+, Zn2+, Fe2+, and Ni2+ are less effective 209840 3.6.1.11 Co2+ reaction requires a divalent metal cofactor 696296 3.6.1.11 Co2+ stimulated by divalent cations, Co2+ is the best stimulator, 6fold at 0.05 mM 209845 3.6.1.11 Cs+ activates wild-type, full-length enzyme paPpx(1-506) 756630 3.6.1.11 Cu2+ 0.01 mM, stimulates 725894 3.6.1.11 Fe2+ 5 mM, 34% of the activation by Mg2+ 209846 3.6.1.11 Fe2+ enzyme is stimulated 0.26fold at a concentration of 2 mM 701387 3.6.1.11 Fe2+ Mn2+ or Co2+ required. Mg2+, Zn2+, Fe2+, and Ni2+ are less effective 209840 3.6.1.11 K+ 100 mM, 30% activity enhancement 654784 3.6.1.11 K+ 20 mM, about 3fold stimulation 734644 3.6.1.11 K+ a nonessential activator of paPpx, presence of K+ does not affect the affinity of the enzyme for Mg2+, activates wild-type, full-length enzyme paPpx(1-506). The activity curve obtained with K+ is sigmoid and reaches its maximum activity at concentrations of 80 mM. Km(app)K+ is 42 mM 756630 3.6.1.11 K+ activates 755891 3.6.1.11 K+ activates 2fold polyphosphatase II, but not activates polyphosphatase I 657203 3.6.1.11 K+ PPX2 activity is increased, 25 mM KCl resulting in a 3fold increase in the specific activity 701387 3.6.1.11 K+ slight activation 654784 3.6.1.11 KCl 175 mM, stimulates 209844 3.6.1.11 KCl 50 and 200 mM, 39 and 38% activity enhancement, respectively 654785 3.6.1.11 Mg2+ - 669880 3.6.1.11 Mg2+ 0.1 mM MgSO4, 5% activity loss 654785 3.6.1.11 Mg2+ 1 mM, 2fold activity enhancement 654785 3.6.1.11 Mg2+ 1 mM, required 209844 3.6.1.11 Mg2+ 1-10 mM, about 7fold activation 209847 3.6.1.11 Mg2+ 1.6fold activation 690206 3.6.1.11 Mg2+ 2.5 mM Mg2+, PPX activity is stimulated by a factor of two in the nuclear fraction and in the mitochondrial fraction 697460 3.6.1.11 Mg2+ 2.5 mM, 15fold activity enhancement 654784 3.6.1.11 Mg2+ 2fold activation at 0.1 mM 654785 3.6.1.11 Mg2+ about 50% of the activity with Mn2+ 677653 3.6.1.11 Mg2+ activates, preferred divalent cation 687628 3.6.1.11 Mg2+ best activator at 1 mM using polyP3, polyP4 and polyP15 as substrates 656105 3.6.1.11 Mg2+ best activator, maximum activity at 5 mM 734644 3.6.1.11 Mg2+ dependent on 711604 3.6.1.11 Mg2+ divalent cation required, Mg2+ is most effective 209850 3.6.1.11 Mg2+ divalent cation required, order of decreasing stimulation: Co2+, Mn2+, Mg2+, Ni2+ 209852 3.6.1.11 Mg2+ enzyme requires Mg2+ cations but is inhibited by higher concentrations, Mg2+ shows the highest stimulation at 2 mM 701387 3.6.1.11 Mg2+ KD: 224.7 +/- 35.1 microM Mg2+ with p-nitrophenyl phosphate, KD: 140.0 +/- 9.99 microM Mg2+ with 5'-AMP 656266 3.6.1.11 Mg2+ may partly substitute for Mn2+ 735058 3.6.1.11 Mg2+ Mn2+ or Co2+ required. Mg2+, Zn2+, Fe2+, and Ni2+ are less effective 209840 3.6.1.11 Mg2+ optimal activity of exopolyphosphatase II in presence of 3 mM 209851 3.6.1.11 Mg2+ poor activation 734338 3.6.1.11 Mg2+ reaction requires a divalent metal cofactor, bound substrate enhances enzyme affinity for the metal ion 696296 3.6.1.11 Mg2+ required 755724, 755891, 755915, 756231 3.6.1.11 Mg2+ required, family I diphosphatases are Mg2+-dependent, activates 756916 3.6.1.11 Mg2+ required, optimal activity at 5 mM 209846 3.6.1.11 Mg2+ required, values of 0.5(app)Mg2+ in paPpx(1-506) and NpaPpx(1-314) are 0.30 mM and 0.28 mM, respectively. The interaction between paPpx(1-506) and Mg2+ occurs in the N-terminal domain 756630 3.6.1.11 Mg2+ single tight binding site for Mg2+ 687678 3.6.1.11 Mg2+ stimulates 209845 3.6.1.11 Mg2+ the activity of NMB1467 is dependent on Mg2+ with optimal activity observed with between 1 and 2 mM 712478 3.6.1.11 Mn2+ 0.5 mM, stimulates 725894 3.6.1.11 Mn2+ 1-10 mM, 3-5fold stimulation 209847 3.6.1.11 Mn2+ 5 mM, about 37% of the activity with Mg2+ 734644 3.6.1.11 Mn2+ 5 mM, about 65% of the activity with Mg2+ 734644 3.6.1.11 Mn2+ activates 687628, 756231 3.6.1.11 Mn2+ best activator for guanosine 5'-tetraphosphate hydrolysis 656105 3.6.1.11 Mn2+ divalent cation required, order of decreasing stimulation: Co2+, Mn2+, Mg2+, Ni2+ 209852 3.6.1.11 Mn2+ enzyme is stimulated 0.86fold at a concentration of 2 mM 701387 3.6.1.11 Mn2+ KD: 7.24 +/- 0.71 microM Mn2+ with p-nitrophenyl phosphate, KD: 2.23 +/- 0.14 micorM Mn2+ with 5'-AMP 656266 3.6.1.11 Mn2+ Mn2+ or Co2+ required. Mg2+, Zn2+, Fe2+, and Ni2+ are less effective 209840 3.6.1.11 Mn2+ poor activition 734338 3.6.1.11 Mn2+ preferred divalent cation, required. Optimal concentration about 10 mM 677653 3.6.1.11 Mn2+ reaction requires a divalent metal cofactor, Mn2+ confers 50% activity compared to Mg2+ in P3 and P4 hydrolysis 696296 3.6.1.11 Mn2+ required 756231 3.6.1.11 Mn2+ required, optimum concentration 1 mM 735058 3.6.1.11 additional information behavior of the full-length paPpx(1-506) and N-paPpx(1-314) against different concentration of divalent ions such as Mg2+, Zn2+, Ca2+, and Mn2+ as effectors, in presence of a saturating concentration (0.008 mM) for the substrate polyphosphate65. The activation of both enzyme variants by Mg2+ is similar and shows no inhibition at high concentrations of this ion. The activation by Ca2+ and Mn2+ is negligible. Li+ and Na+ have no effects on enzyme activity, while NH4+, K+, Rb+, and Cs+ are activators of paPpx(1-506). Tetramethylammonium is not an activator of paPpx(1-506) 756630 3.6.1.11 additional information enzyme TbNH2 is able to hydrolyze polyphosphate with Mg2+ and Co2+ as cofactors, but has lower activity with Mn2+ 756231 3.6.1.11 additional information exopolyphosphatase I does not require divalent cations 209851 3.6.1.11 additional information Mg2+ or Mn2+ are the preferred cofactors while no activity is detected with Co2+ 756231 3.6.1.11 additional information no activity measured in absence of divalent cations 656105 3.6.1.11 additional information no activity with Ca2+, Co2+, Cu2+ or Fe2+ ions 735058 3.6.1.11 additional information no effect on activity by Mn2+ and Zn2+ 756916 3.6.1.11 additional information presence of divalent cation is absolutely required, Mg2+ is preferred 734644 3.6.1.11 additional information stimulated by divalent cations to a lesser extent 654785 3.6.1.11 NaCl 50 and 200 mM, 46 and 42% activity enhancement, respectively 654785 3.6.1.11 NH4+ 100 mM, 35% activity enhancement 654784 3.6.1.11 NH4+ activates wild-type, full-length enzyme paPpx(1-506). The activity curve obtained with NH4+ is sigmoid and reaches its maximum activity at concentrations of 30 mM. Km(app)NH4+ is 10 mM 756630 3.6.1.11 NH4+ slight activation 654784 3.6.1.11 NH4Cl 50 and 200 mM, 42 and 67% activity enhancement, respectively 654785 3.6.1.11 Ni2+ 5 mM, 32% of the activation by Mg2+ 209846 3.6.1.11 Ni2+ divalent cation required, order of decreasing stimulation: Co2+, Mn2+, Mg2+, Ni2+ 209852 3.6.1.11 Ni2+ KD: 72.3 +/- 7.61 microM Ni2+ with p-nitrophenyl phosphate, KD: 29.4 +/- 3.69 microM Ni2+ with 5'-AMP 656266 3.6.1.11 Ni2+ Mn2+ or Co2+ required. Mg2+, Zn2+, Fe2+, and Ni2+ are less effective 209840 3.6.1.11 Rb+ activates wild-type, full-length enzyme paPpx(1-506) 756630 3.6.1.11 Zn2+ 0.1 mM ZnSO4, 76% activity loss 654785 3.6.1.11 Zn2+ 1.5fold activation at 0.1 mM 654785 3.6.1.11 Zn2+ enzyme is stimulated 0.11fold at a concentration of 2 mM 701387 3.6.1.11 Zn2+ may partly substitute for Mn2+ 735058 3.6.1.11 Zn2+ Mn2+ or Co2+ required. Mg2+, Zn2+, Fe2+, and Ni2+ are less effective 209840 3.6.1.11 Zn2+ stimulated in the micromolar range to a lower extent than Cu2+ and Mn2+ 725894 3.6.1.11 Zn2+ stimulates 209845 3.6.1.11 Zn2+ Zn2+ is able to activate the enzyme only 20% compared to Mg2+ 756630