TABLE 1.

Overexpression and purification of MCO from E. coli BL21(DE3)(pLysS)^a

Step	Protein (mg)	Total activity (U)b	Sp actc (U/mg)
Crude extract	21	19.9 ± 1.3	1.6 ± 0.2
Ni column elute	0.6	42.0 ± 2.0	9.7 ± 0.3

^aEnzyme activity was measured using 3,3′-dimethoxybenzidine as a substrate. The reaction was initiated by the addition of 0.472 μmol of 3,3′-dimethoxybenzidine (o-dianisidine) and terminated after 5 and 120 min.

^bOne unit of activity catalyzed the oxidation of 1 μmol of substrate per min.

^cSpecific activity is defined as the μmol of substrate oxidized per min per mg of total protein.