Table I.

Activity of CCoAOMT in the presence of different metal cations

Row 1 refers to CCoAOMT untreated by EDTA, row 2 CCoAOMT dialyzed overnight with 5 mm EDTA, and rows 3 to 6 after EDTA treatment (EDTA was depleted and 2 mm of the appropriate metal cation was added). All assays used 0.1 mm caffeoyl CoA and 0.1 mm ¹⁴C-labeled SAM. Activity expressed as counts per microgram of CCoAOMT for untreated CCoAOMT assayed in the presence of 2 mm Mg²⁺ was set to 100% and all other reactions were then referenced to this value. Specific activities for untreated CCoAOMT were as reported previously (Inoue et al., 1998).

	Activity (% of Wild Type)
CCoAOMT	100
CCoAOMT + 5 mm EDTA	15
CCoAOMT + 1 mm Ca2+	100
CCoAOMT + 1 mm Mg2+	100
CCoAOMT + 1 mm Zn2+	100
CCoAOMT + 1 mm Mn2+	35