TABLE 3.
β-Lactam | PER-6 |
PER-2 |
||
---|---|---|---|---|
kcat (s−1) | Km (μM) | kcat/Km (mM−1·s−1) | kcat/Km (mM−1·s−1) | |
Benzylpenicillin | 5 | 200 | 25 | 120 |
Ampicillin | 1 | 20 | 50 | 330 |
Ticarcillin | 0.4 | 9 | 50 | ND |
Piperacillin | 0.1 | 4 | 25 | 200 |
Cephalothin | 8 | 55 | 145 | 670 |
Ceftazidime | 12 | 1,000 | 10 | 430 |
Cefotaxime | 40 | 900 | 45 | 760 |
Cefepime | 10 | 2,000 | 5 | 20 |
Cefpirome | 12 | 1,500 | 8 | NA |
Cefoxitin | ND | ND | ND | <10 |
Aztreonam | 3 | 40 | 75 | 120 |
Moxalactam | ND | ND | ND | NA |
Imipenem | 0.006 | 1.5 | 4 | <10 |
Meropenem | 0.004 | 10 | 0.4 | NA |
Ertapenem | 0.002 | 7 | 0.3 | NA |
Data are means of results from three independent experiments. Standard deviations were within 10% of the means. ND, not determinable or no detectable hydrolysis (<0.01 s−1); NA, not available.