Table 1 Effect on metal ions and chelating agent EDTA on hydrolytic activity. The enzyme purified without divalent cations added served as the control. The divalent metal salts or EDTA were added to this sample. The highest activity was observed when 1 mM ZnCl2 was added in all purification buffers and was set to 100%
Metal ion or chelating agent | Relative activity [%] | Specific activity [U/mg] |
|---|---|---|
Control | 51 | 65.2 (± 0.6) |
1 mM EDTA | 36 | 45.7 (± 3.6) |
Purified with 1 mM ZnCl2 | 100 | 127.2 (± 0.6) |
Purified with 1 mM ZnCl2, 1 mM EDTA added | 96 | 122.7 (± 1.6) |
1 mM ZnCl2 | 84 | 106.8 (± 8.6) |
0.5 mM ZnCl2 | 81 | 103.5 (± 6.6) |
0.1 mM ZnCl2 | 84 | 107.3 (± 5.8) |
0.05 mM ZnCl2 | 85 | 107.9 (± 6.2) |
0.01 mM ZnCl2 | 86 | 109.7 (± 4.0) |
0.001 mM ZnCl2 | 65 | 82.3 (± 7.0) |
1 mM MgSO4 | 47 | 60.3 (± 4.2) |
1 mM MnCl2 | 48 | 60.9 (± 4.4) |
1 mM CaCl2 | 50 | 63.8 (± 2.1) |
1 mM CoCl2 | 52 | 66.0 (± 8.7) |
1 mM NiSO4 | 43 | 54.4 (± 5.5) |
1 mM FeSO4 | 42 | 52.9 (± 1.1) |
1 mM CuSO4 | 40 | 51.2 (± 0.1) |