Figure 4.

The pH dependence of k_cat/ (mM⁻¹s⁻¹) for the hydrolysis of l-Cth catalyzed by eCBL (○) and the R58A (•) R58K (Δ) site-directed mutants. Inset: Comparison of the pH dependence of k_cat/ (mM⁻¹s⁻¹) for eCBL (○) and the R372K (♦) mutant. Reaction conditions: MBP buffer (50 mM MOPS, 50 mM Bicine and 50 mM proline), 20 μM PLP, 2 mM DTNB, 0.01–6.25 mM l-Cth and 0.068–4.5 μM enzyme. The data were fit to equation 2.