FIGURE 7.

GCL high molecular weight forms increase following oxidative stress. A, extracts of control and phorone-treated Jurkat cells were resolved by native PAGE and stained for GCLC (left panel) and GCLM (right panel). Duplicate lanes were run with 100 μg and 50 μg of cytosolic protein. Markers indicate position of BSA run as a standard on the gel. B, densitometry analysis of the GCLC monomer, holoenzyme, and high molecular weight forms detected following native PAGE of Jurkat cells treated with phorone or H₂O₂ (n = 3–6 experiments). The percentages of total GCLC in each form, average ± S.D., are shown. *, statistically different from control by Wilcoxon rank sum test (p < 0.05). C, SEC analysis of control and phorone-treated Jurkat cells. SEC fractions were eluted, resolved by SDS-PAGE, and stained for GCLC. An elution profile of GCLC for a single experiment is shown. D, cumulative percentage of GCLC eluted from three SEC experiments; 2-ml elution fractions are presented as cumulative flow volume.