Skip to main content
. 2012 Apr;56(4):2187–2190. doi: 10.1128/AAC.05838-11

Table 2.

Kinetic parameters for β-lactamases IMP-29 and IMP-1a

Substrate Km (μM)
 kcat (s−1)
 kcat/Km (μM−1 · s−1)
IMP-29 IMP-1 IMP-29 IMP-1 IMP-29 IMP-1
Benzylpenicillin 130 520 140 320 1.1 0.62
Piperacillin 10 356 50 5 0.72
Cefotaxime 300 4 3 1.3 0.01 0.35
Ceftazidime 800 44 2 8 0.0025 0.18
Cefepime 110 11 1 7 0.01 0.63
Aztreonam ND >1,000 NH <0.01 ND ND
Imipenem 50 39 3 46 0.06 1.17
Meropenem 90 10 6 5 0.07 0.50
Ertapenem 150 16 7 21 0.045 0.76
a

Data for IMP-1 are from references 14 and 1. Data are the means of three independent experiments. Standard deviations were within 10% of the means. NH, no detectable hydrolysis; ND, not determined.