TABLE 2.

Effects of chemical reagents on the activity of LAMY

Additive	Reagent concn (mM)	Residual activity (%)a
None		100
N-Bromosuccinimideb	0.1	0
Iodoacetatec	0.5	2
N-Ethylmaleimide	1	107
p-Chloromercuribenzoatec	0.5	80
Citrate	10	98
EDTA	10	10
EGTA	10	9

^aEnzymatic activity was measured after the enzyme had been treated with each inhibitor for 30 min at the indicated temperature and pH in the appropriate buffer. Usually, the enzyme was treated with inhibitor at 30°C and at pH 8.5 in 50 mM Tris-HCl buffer, and an aliquot (0.1 ml) was used for assay of the residual activity in the standard buffer. The values shown are the percentages of the activity without additives, which is taken as 100%. 

^bPreincubated for 15 min at 4°C and at pH 5.0 in 10 mM acetate buffer. 

^cPreincubated for 15 min at 40°C and at pH 5.5 in 10 mM acetate buffer.