Table 3.

Kinetic data for ACC-1

SubstrateVmax (nmol of substrate/ min/μg of protein)RelativeVmaxKm (μM)Vmax/Km
Cephaloridine30.7 ± 3.0100122 ± 160.25
Nitrocefin63.7 ± 2.220828 ± 3.72.3
Piperacillin0.17 ± 0.050.551.4 ± 0.60.12
Ceftazidime<0.025≤0.117a <0.01
Cefotaxime<0.01 <0.02NDb ND
Cefotetan<0.001<0.01NDND
Cefoxitin<0.002<0.01NDND
  • a Ki value was determined by using cephaloridine as substrate.

  • b Rates were too slow to determine aKm from steady-state hydrolysis rates.