FIG. 3.

H₂O₂ generation by human recombinant CYP2E1 and effects of exogenous cytochrome b5. Upper panel: Protein- and time-dependent generation of H₂O₂ by human recombinant CYP2E1. Note that the reactions were linear for at least 10 min. Lower panel: The effects of inhibitors on the generation of H₂O₂ by human recombinant CYP2E1. Reactions contained 2.0 pmol of CYP2E1. All reactions were run for 6 min before analysis of H₂O₂ in reaction mixes. Note that the addition of purified human cytochrome b5 (at a ratio of cytochrome b5 to CYP2E1 of 5:1) had small effect on H₂O₂ generation activity. In all cases, the values are the mean ± SD of three independent experiments with samples analyzed in duplicate.