Table II.
Kinetic analysis of ADK1 and 2
| Adenosine Kinase | Substrate | Km | Vmax | Vmax/Km |
|---|---|---|---|---|
| μm | μmol min−1 mg−1 protein | L min−1 mg−1 protein | ||
| ADK1 | Adenosine | 0.50 | 2.7 | 5.4 |
| ATP | 350 | 3.5 | 0.010 | |
| Isopentyladenosine | 3.2 | 0.068 | 0.021 | |
| ADK2 | Adenosine | 0.30 | 6.7 | 22 |
| ATP | 370 | 7.8 | 0.021 | |
| Isopentyladenosine | 4.8 | 0.66 | 0.14 |
Purified recombinant ADK1 and 2 were used to determine both Km and Vmax for three substrates of adenosine kinase. Vmax/Km is presented here as a measure of overall enzyme efficiency for each substrate. Assays were as described in “Materials and Methods.”