Table 2.

Kinetic parameters of TEM-2 and TEM-59/IRT-17

AntibioticTEM-2TEM-59/IRT-17
Km (μM)Rel Vmax(%)aKm (μM)RelVmax (%)
Benzylpenicillin18100140100
Ampicillin209358054
Amoxicillin258052055
Ticarcillin1213 —b 2
Piperacillin4085120183
Cephalothin35020<1
Cephaloridine80055<1
Cefoperazone230471.5
  • a Vmax expressed relative to benzylpenicillin (100%).

  • b —, Km value too high to be accurately determined.