Table 3.

Steady-state kinetic parameters of VEB-1 β-lactamase

SubstrateVmaxrelKm(μM)Vmaxrel/ Kma
Benzylpenicillin1002.8100
Amoxicillin1106.050
Ticarcillin81.022
Cephalothin7006.0325
Cephaloridine2,30012.0533
Cefamandole8005.6397
Cefoperazone1404.586
Ceftriaxone2,90022.0366
Cefotaxime4,30038.0314
Cefuroxime2,00024.0230
Ceftazidime8,000460.047
Aztreonam400500.02
  • a Values relative to that of benzylpenicillin, which was set at 100.