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).