TABLE 1.
Steady-state kinetic constants of recombinant L1 and metallo-β-lactamase isolated from S. maltophilia ULA-511
| Compound | Recombinant L1
|
ULA-511
|
||||||
|---|---|---|---|---|---|---|---|---|
| Km (μM) | kcat (s−1) | kcat/Km (s−1 μM−1) | Km (μM) | kcat (s−1) | kcat/Km (s−1 μM−1) | Buffera | Reference | |
| Piperacillin | 200 ± 20 | 420 ± 20 | 2.1 | 20 ± 1 | 140 | 7.1 | B | 9 |
| Ampicillin | 300 ± 15 | 580 ± 20 | 1.9 | 40 ± 3 | 175 | 4.4 | A | 10 |
| Cefuroxime | 130 ± 40 | 53 ± 9 | 0.41 | 30 ± 3 | 80 | 2.7 | A | 10 |
| BRL42715 | 600 ± 70 | 170 ± 10 | 0.28 | 270 ± 10 | 0.55 | 0.0020 | D | 16 |
| Penicillin G | 75 ± 10 | 410 ± 20 | 5.5 | 50 ± 6 | 1,100 | 22 | A | 10 |
| Cefprozil | 100 ± 20 | 15 ± 1 | 0.15 | |||||
| Cefotaxime | 160 ± 20 | 140 ± 9 | 0.88 | 26 ± 3 | 66 | 2.5 | A | 10 |
| Ticarcillin | 490 ± 100 | 440 ± 70 | 0.90 | 140 ± 2 | 375 | 2.7 | B | 9 |
| Biapenem | 75 ± 11 | 64 ± 4 | 0.85 | 56 ± 1 | 65 | 1.2 | C | 12 |
| Nitrocefin | 12 ± 1 | 31 ± 1 | 2.6 | 7 ± 1 | 20 | 2.9 | A | 10 |
| Cephalothin | 43 ± 7 | 65 ± 3 | 1.5 | 90.9 | ||||
| Cefaclor | 31 ± 3 | 16 ± 1 | 0.52 | |||||
| Cephaloridine | 170 ± 30 | 67 ± 5 | 0.39 | 300 ± 50 | 28 | 0.093 | A | 10 |
| Cephradine | 260 ± 40 | 16 ± 1 | 0.062 | 50 ± 5 | 12.5 | 0.25 | B | 9 |
| Ceftizoxime | 7.9 ± 1.6 | 2.7 ± 0.1 | 0.34 | |||||
| Cefoxitin | 3.3 ± 0.4 | 2.2 ± 0.1 | 0.67 | 2 ± 0.05 | 1.10 | 0.55 | A | 10 |
| Cefmetazole | 4.1 ± 0.2 | 4.7 ± 0.1 | 1.1 | |||||
| Cephalosporin C | 180 ± 18 | 280 ± 13 | 1.6 | 25 ± 1 | 62 | 2.5 | E | 11 |
| Clavulanic acid | 22 ± 2 | 11 ± 1 | 0.50 | |||||
| Moxalactam | 5 ± 1 | 0.15 ± 0.01 | 0.030 | 1 ± 0.05 | 0.29 | 0.29 | A | 10 |
| Cefadroxil | 250 ± 50 | 23 ± 2 | 0.092 | |||||
| Cefepime | 130 ± 30 | 0.33 ± 0.04 | 0.025 | >1,000 | >15.0 | B | 9 | |
| Azlocillin | 59 ± 6 | 37 ± 2 | 0.63 | 6 ± 0.1 | 75 | 13 | B | 9 |
| Cefsulodin | 32 ± 5 | 0.086 ± 0.005 | 0.0027 | 5 ± 0.3 | 7.5 | 1.5 | B | 9 |
a
Buffer A was 50 mM sodium cacodylate, pH 7.0, containing 100 μM Zn(II) at 35°C. Buffer B was 30 mM sodium cacodylate, pH 6.5, containing 100 μM Zn(II) at 30°C. Buffer C was 30 mM sodium cacodylate, pH 6.5, containing 100 μM Zn(II) at 30°C. Buffer D was 50 mM sodium cacodylate, pH 7.0, containing 100 μM Zn(II) at 35°C. Buffer E was 30 mM sodium cacodylate, pH 7.0, containing 50 μM Zn(II) at 30°C.