TABLE 2.

Effect of metal ions and EDTA on EsiLeuDH activity.

Metal ion (1 mM)	Relative activity (%)
None	100 ± 2.7
Na+	102.74 ± 1.1
Ca2+	101.53 ± 3.8
Mg2+	97.04 ± 0.35
Mn2+	95.83 ± 5.5
Cu2+	95.29 ± 4.1
Zn2+	92.48 ± 1.7
Fe2+	59.5 ± 5.8
Fe3+	47.95 ± 3.9
EDTA	85.79 ± 1.7

The EsiLeuDH was preincubated in 1 M NH₄Cl-NH₃⋅H₂O buffer (pH 8.5) containing 1.0 mM of various metal ions or EDTA at 30°C for 2 h, then the activity toward TMP was measured under standard conditions. The control enzyme activity was assayed in the absence of any test compound.