Figure 2.

Effect of 6-phosphogluconate dehydratase overproduction or exposure to paraquat upon the EPR signals of SOD-proficient cells. Assay conditions were similar to those described in Fig. 1, except: power = 50 mW, modulation amplitude = 16 G, and receiver gain = 20,000. Scans: A, wild-type cells (AB1157), 10 μM intracellular free iron; B, 6-phosphogluconate dehydratase overproducer (KK230), 35 μM iron; C, AB1157 during exposure to 200 μM paraquat, 40 μM iron. This concentration of paraquat was just sufficient to reduce the rate of growth by about 50%.