Table 4.

Effects of metal ions, chelators, and thiol-blocking reagents on the activity of XylB_ADP1 with benzaldehyde and NADH as the substrate^a

Inhibitor	Concn (μM)	Residual activity (%)
None (control)		100.0
Ag+	1	100.1
	10	0.2
	100	0
Ca2+	1,000	119.3
Co2+	1,000	115.2
Cu2+	1	105.8
	10	33.4
	100	1.3
	1,000	0
Fe2+	1	109.9
	10	113.4
	100	62.6
	1,000	21.7
Hg2+	1	0.1
Mg2+	1,000	112.9
Mn2+	1,000	128.0
Ni2+	1,000	107.4
Zn2+	1	105.8
	10	64.5
	100	20.5
	1,000	1.2
EDTA	1,000	120.9
1,10-Phenanthroline	1,000	85.5
Iodoacetamide	1,000	123.5
N-Ethylmaleimide	1	97.5
	10	79.0
	100	63.4
	1,000	57.4

^aEach value is an average of three independently determined values. Residual activity was measured relative to the activity in an inhibitor-free assay with benzaldehyde and NADH.