TABLE 3.
Substrate specificity of CoMAa
| Substrateb | Solubility | Mean relative activity (%) ± SD |
|---|---|---|
| Starch from potato | Soluble | 46.8 ± 3.4 |
| Dextrin from corn | Soluble | 78.5 ± 7.4 |
| Soluble starch | Soluble | 100.00 |
| Amylose from potato | Insoluble | 35.1 ± 0.2 |
| Amylopectin from potato | Soluble | 12.5 ± 0.5 |
| Glycogen from bovine muscle | Soluble | 2.1 ± 0.3 |
| Pullulan | Soluble | 14.3 ± 1.5 |
| α-Cyclodextrin | Soluble | ND |
| β-Cyclodextrin | Soluble | ND |
| γ-Cyclodextrin | Soluble | 20.2 ± 2.1 |
| Dextran 64-74 | Soluble | ND |
| Dextran 10 | Soluble | ND |
| Panose* | Soluble | ND |
| Isomaltotriose* | Soluble | ND |
| Maltose* | Soluble | ND |
| Acarbose* | Soluble | ND |
a
For the determination of substrate specificity, the purified CoMA was incubated in 20 mM Tris-HCl buffer (pH 7.0) for 10 min at 50°C with 0.5% (wt/vol) concentrations of different substrates. Activity was measured using the DNS method (48). The activity against soluble starch was set as the 100% value by the addition of 0.3 μg of purified CoMA with 980 U/mg protein. ND, no activity detected. Mean values from three independent experiments are shown.
b
*, enzyme activity was measured by TLC or HPLC.