Fig. 5. Calcium-dependent structure and activity of SlpE and serralysin proteases.
The Ca2+-dependent activation of serralysin and related proteases is shown. Calcium is required for the activity of many proteases; this experiment was performed to determine whether SlpE activity requires calcium. The mean steady state reaction velocities for each protease were normalized to that of PrtS after refolding in the presence or absence of 2 mM Ca2+ using a fluorescent substrate .