TABLE 3.
Effect of enzyme preincubation (2 min) in the presence of various reagents on HicDH activitya
| Enzyme treatment | Relative activity |
|---|---|
| Control | 100 |
| 1 mM MgCl2 | 83 ± 7 |
| 1 mM CaCl2 | 72 ± 3 |
| 10 mM EDTA | 160 ± 21 |
| 0.1 mM CuSO4 | 0 |
| 0.1 mM HgCl2 | 0 |
| 0.1 mM iodoacetamide | 95 ± 14 |
| 20 mM dithiothreitol | 154 ± 5 |
| 1 mM DEPC | 65 ± 1 |
| 2 mM DEPC | 12 ± 3 |
a
Activities were determined with 10 mM 2-ketoisocaproate and 3 mM NADH in 100 mM phosphate buffer, pH 7.0, at 37°C. Values are given as mean percentages ± standard deviations of the activity in the control sample.