Table 3. Kinetic parameters of AarA, ecGlpG and hiGlpG using FL‐casein as a substrate
RhomboidKM (μM)Vmax (μM min−1)kcat (min−1)kcat/KM (μM−1 min−1)
AarA1.8 ± 0.470.066 ± 0.0120.36 ± 0.0680.2 ± 0.092
ecGlpG2.5 ± 0.370.067 ± 0.0220.37 ± 0.1220.148 ± 0.068
hiGlpG6.5 ± 2.10.070 ± 0.0690.38 ± 0.0370.05 ± 0.020
  • The reaction mixture contained 0.179–8.95 μM of BODIPY FL‐casein, activity buffer (50 mM MES, pH 6.0, 150 mM NaCl, 20% glycerol, 0.1% DDM) and 0.179 μM of rhomboid enzyme. The substrate was mixed with the activity buffer and incubated at 37°C for 1 h in the dark. The reaction was started with the protease. Fluorescence emission at 513 nm was measured at 37°C every 5 min over 2 h in a FluoStar fluorescence microplate reader with an excitation wavelength of 503 nm.