Figure 3.

The pH dependence of specific activity for the hydrolysis of l-Cth catalyzed by eCBL (×) and the R59A (○) and R59K (•) mutants site-directed mutants. Inset: Comparison of the pH dependence of the specific activity of eCBL (×), R58A (○) and R58K (•). Reaction conditions: MBP buffer (50 mM MOPS, 50 mM Bicine and 50 mM proline), 20 μM PLP, 2 mM DTNB, 6.25 mM l-Cth and 68 nM eCBL, 0.96 μM R58A, 0.56 μM R58K, 58 nM R59A or 0.13 μM R59K. Measurements were performed in quadruplicate, as represented by the error bars.