Figure 4 - Effect of the presence of scavengers on the URO I-induced enzyme inactivation. ALA-D, PBGase, PBG-D and URO-D were preincubated for 30 min at 30oC in the presence of histidine (15 mM), sodium azide (15 mM), catalase (200 nM), reduced glutathione (15 mM), ethanol (15 mM), glucose (11 mM), dimethyl sulfoxide (1.2 mM) or superoxide dismutase (10 mM), and then exposed to 10 mM (A, B, C) or 100 mM (D) URO I for 2 h at 37oC, under UV light.