TABLE 3.
Pretreatmenta | Metal(s) added (1 mM concn) | Activity (%)b
|
|
---|---|---|---|
YesW | YesX | ||
CaCl2 (1 mM) | CaCl2 | 100 | 100 |
None | 0 | 7 | |
EGTA (10 mM) | None | 0 | 0 |
EDTA (10 mM) | None | 0 | 0 |
AlCl3 | 0 | 16 | |
MgCl2 | 4 | 0 | |
MnCl2 | 134 | 661 | |
CaCl2 | 54 | 89 | |
CoCl2 | 54 | 111 | |
ZnCl2 | 21 | 579 |
YesW and YesX were treated with 10 mM EDTA or EGTA and then dialyzed against 20 mM of Tris-HCl (pH 7.5) containing 0.2 M NaCl. The activity of these enzymes pretreated with EDTA was determined in the presence of different metal ions at the indicated concentration.
The activity of chelator-treated enzymes in the presence of CaCl2 is taken as 100%.