Figure 6.

Dependence of the activity of reconstituted EAL on the presence of different disulfide reducing agents. Activity reprents the maximum turnover number (k_cat) attained at excess ethanolamine substrate (concentration≫K_M), under the assay conditions described in Methods. The EutB and EutC proteins were present at stoichiometric concentrations. The bars correspond to the following conditions: Control 1: Reductant was omitted during the purification procedure and during activity measurement. All other samples were purified in the presence of 5 mM TCEP reductant, which was removed as a consequence of the gel filtration step of the purification procedure. Control 2: No reductant added to the kinetic assay mixture. β-ME: β-mercaptoethanol (5 mM) added to kinetic assay mixture. DTT: Dithiothreitol (5 mM) added to assay mixture. TCEP: Tris-2-carboxyethyl phosphine (5 mM) added to assay mixture. Values represent the averages and standard deviation (error bars) of three measurements.