Figure 5.

The dependence of enzyme activity on AVG concentration for wild-type eCBL (○) and the R58K (•), D116N (×) and W340 (▴) site-directed mutants. Inset: Comparison of the effect of AVG inhibitor concentration on the activity of eCBL (○) and the R372K (◊) mutant. Reaction conditions: The enzyme (32 nM eCBL, 4.3 μM R58K, 24 nM D116N, 57 nM W340 and 1.9 μM R372K) was mixed with 0.05–10⁴ μM AVG in 50 mM Tris, pH 8.5, containing 20 μM PLP, and incubated at 25 °C for 10 min. Activity was subsequently measured in quadruplicate, as represented by the error bars, at a l-Cth substrate concentration of 0.1 mM and the data was fit to equation 3 to obtain the IC₅₀ value for each enzyme.