TABLE 3.

Activity of AtAMY3 and its cysteine mutant variants against BPNP-G7 under reducing or oxidizing conditions

Purified recombinant proteins (10 μg) were exposed to 5 mm DTT or 50 μm CuCl₂ for 1 h prior to activity assay. Values represent the mean ± S.E. (n = 3).

	Reduced activity	Oxidized activity
	nmol min−1 mg−1	nmol min−1 mg−1	% of reduced activity
WT	31.6 ± 0.5	0.06 ± 0.03	<1%a
C118S	27.7 ± 0.5	0.06 ± 0.03	<1%a
C285S	11.1 ± 0.6	0.14 ± 0.05	1%a
C310S	21.7 ± 0.4	0.03 ± 0.03	<1%a
C363S	44.4 ± 0.4	0.13 ± 0.03	<1%a
C499S	2.4 ± 0.1	0 ± 0	0%a
C587S	3.9 ± 0.2	3.3 ± 0.2	85%
C652S	17.2 ± 0.3	0.06 ± 0.03	<1%a
C743S	29.1 ± 0.5	0.6 ± 0.3	2%a
C832S	33.3 ± 0.7	0 ± 0	0%a

^a Data denote significant difference (p < 0.05) between reduced and oxidised activities with a two-tailed t test.