Figure 5. Analyses on factors affecting the activity of recombinant UGT74D1.

(A) The effects of temperature. (B) The effects of buffer and pH value. All the reaction mix (100 µl) contained 0.2 ug of recombinant UGT74D1, 5 mM UDP-glucose, 1 mM IBA, 2.5 mM MgSO₄, 10 mM KCl, 14.4 mM 2-mercaptoethanol, 50 mM buffer and was incubated for 30 min as described in “Materials and Methods ”. The results represent means±SD from three replicates. The specific enzyme activity was defined as nmol of substrates converted into glucose conjugates per second (nanokatal, nkat) by 1 mg of protein.