Figure 4.
pH-dependence of LpxC-catalyzed deacetylase activity for Zn2+-C63A (●) or Fe2+ - C63A (○) LpxC. The values of V/K were measured at 30 °C using subsaturating concentrations of myr-UDPGlcNAc (≤ 0.2 μM) and enzyme reconstituted with stoichiometric metal ion, as described under “Materials and Methods”. The pKa values (see Table 1) were determined by fitting Eq. 1 to the data.