TABLE 3.
Substrate specificity of the GIK from A. pernix with alternate substratesa
| Substrate | Apparent Vmax (U/mg) | Apparent Km (μM) | kcat (s−1) | kcat/Km (μM−1 s−1) |
|---|---|---|---|---|
| Glucose | 35 | 44 | 23 | 0.53 |
| 2-Deoxyglucose | 45 | 330 | 30 | 0.09 |
| Glucosamine | 27 | 60 | 18 | 0.30 |
| Fructose | 15 | 150 | 10 | 0.07 |
| Mannose | 19 | 110 | 13 | 0.12 |
| N-Acetylglucosamine | 2 | ND | 1 | |
| N-Acetylmannosamine | 1.5 | ND | 0.8 |
a
ATP (2 mM) was used as a phosphoryl donor. Enzyme activity was measured at 90°C in a discontinuous assay with LDH and PK as described in Materials and Methods.