TABLE 2.
Kinetic activity of AmpCD and AmpCR
| Substrate | AmpCD
|
AmpCR
|
||||
|---|---|---|---|---|---|---|
| Km (μM) | kcat (s−1) | kcat/Km (M−1 s−1) | Km (μM) | kcat (s−1) | kcat/Km (M−1 s−1) | |
| Cephaloridine | 100 ± 10 | 64 ± 4 | 6.4 × 105 | 780 ± 40 | 300 ± 10 | 3.9 × 105 |
| Ampicillin | 6.2 ± 1.6 | 0.43 ± 0.06 | 7.0 × 104 | 13 ± 3 | 4.0 ± 0.3 | 3.2 × 105 |
| Cefoxitin | 1.2 ± 0.3 | 0.043 ± 0.006 | 3.8 × 104 | 3.9 ± 0.1 | 0.35 ± 0.01 | 9.1 × 104 |
| Ceftazidime | 5.7 ± 0.8 | 0.084 ± 0.006 | 1.5 × 104 | 550 ± 10 | 3.5 ± 0.1 | 6.4 × 103 |
| Cefotaxime | 31 ± 8 | 0.37 ± 0.02 | 1.2 × 104 | 13 ± 2 | 1.2 ± 0.1 | 9.7 × 104 |
| Cefpirome | 21 ± 1 | 1.5 ± 0.1 | 7.1 × 104 | 120 ± 20 | 0.21 ± 0.03 | 1.8 × 103 |
| Cefepime | 49 ± 5 | 1.0 ± 0.1 | 2.1 × 104 | 200 ± 40 | 0.21 ± 0.02 | 1.1 × 103 |