Table 2.
Characteristics of the soluble acid invertase PrSAI1 purified from growing subterranean shoots of Phelipanche ramosa parasitizing tomato plants.
| Kinetic properties | |
| pI | 4.6 ± 0.1 |
| Optimal pH | 4.5 ± 0.1 |
| Optimal temperature (°C) | 50 ± 3 |
| Molecular mass (kDa) | |
| Native form | 86 ± 4 |
| Denatured form | 35 ± 2 |
| Substrate specificity (mm) | |
| K m(sucrose) | 2.7 ± 0.3 |
| K m(stachyose) | 16.9 ± 2.4 |
| K m(raffinose) | 75.6 ± 5.5 |
| K m(cellobiose, lactose, maltose, melezitose, melibiose, methyl‐glucose, trehalose, verbascose) | — |
| Inhibition | |
| K i(fructose) (mm) | 1.6 ± 0.1 |
| K i(glucose) (mm) | 12.0 ± 0.4 |
| MnCl2, CoCl2 (1 mm, % control) | 110 ± 3.1 |
| CaCl2 (1 mm, % control) | 86 ± 6.1 |
| AgNO3, KCl, NaCl, MgCl2 (1 mm, % control) | 70.5 ± 2.4 |
| CuSO4, ZnSO4, PbNO3 (1 mm, % control) | 48.7 ± 7.3 |
| HgCl2 (1 mm, % control) | 9 ± 2.0 |
Values are means ± standard error (n= 3).