TABLE 2

Initial-rate kinetics of native wild-type FOX-4 and other class C enzymes

Enzyme by drugKm (μM)kcat (s−1)kcat/Km (μM−1s−1)
Cefoxitin
    FOX-4a0.11 ± 0.010.91 ± 0.068.3 ± 0.9
    P. aeruginosa AmpCb0.050.122.4
    CMY-2c0.070.233.3
    C. freundii AmpCb0.250.0321.3
    K-12 AmpCb0.650.20.3
    P99 AmpCb0.0240.062.5
Cefotaxime
    FOX-40.12 ± 0.010.47 ± 0.013.9 ± 0.1
    P. aeruginosa AmpCb0.20.150.75
    CMY-2c0.0040.00123.3
    C. freundii AmpCb0.0050.0173.4
    K-12 AmpCb1.70.170.1
    P99 AmpCb0.010.0151.5
Ceftazidime
    FOX-4a4.1 ± 0.10.30 ± 0.010.073 ± 0.001
    P99 AmpCd40.0120.003
  • a Data from this study.

  • b Data from Galleni et al. (34).

  • c Data from Bauvois et al. (35).

  • d Data from Matagne et al. (41).