TABLE 4

Kinetic values of recombinantly expressed and purified OXA-48, OXA-48:P68A, and OXA-48:P68A,Y211Sa

SubstratebOXA-48OXA-48:P68AOXA-48:P68A,Y211S
Km (µM)kcat (s−1)kcat/Km
(s−1 mM−1)
Km (µM)kcat (s−1)kcat/Km
(s−1 mM−1)
Km (µM)kcat (s−1)kcat/Km
(s−1 mM−1)
AMP370 ± 70608 ± 531,643 ± 45577 ± 1225 ± 1331 ± 66211 ± 2618 ± 186 ± 14
PIP898 ± 1553.9 ± 0.54 ± 1290 ± 670.15 ± 0.020.5 ± 0.2155 ± 380.06 ± 0.010.4 ± 0.2
NIT226 ± 34141 ± 12624 ± 14853 ± 837 ± 2703 ± 14963 ± 912 ± 1193 ± 40
CAZ300 ± 1503.0 ± 0.810 ± 8220 ± 5026 ± 3117 ± 41190 ± 4042 ± 5220 ± 72
FEP1,678 ± 6861.7 ± 0.61.0 ± 0.8462 ± 1260.5 ± 0.11.2 ± 0.51,459 ± 6351.1 ± 0.40.8 ± 0.6
IMI13 ± 24.8 ± 0.2365 ± 714.2 ± 0.90.80 ± 0.04190 ± 5014 ± 30.57 ± 0.0441 ± 11
MEM4 ± 10.71 ± 0.02177 ± 503 ± 1(8 ± 0.8) × 10−40.3 ± 0.12 ± 1(2 ± 0.2) × 10−31.2 ± 0.7
  • a Errors are displayed as 95% confidence intervals based on a minimum of triplicates.

  • b AMP, ampicillin; PIP, piperacillin; NIT, nitrocefin; CAZ, ceftazidime; FEP, cefepime; IMI, imipenem; MEM, meropenem.