FIG. 1.

MccJ25 effect on the time course of superoxide production by E. coli membrane. A solution containing membranes (1 mg protein [prot.]·ml⁻¹) and 40 mM cytochrome c in 50 mM phosphate buffer, pH 7.8 (final volume, 0.6 ml), was incubated in the absence (▪) and in the presence (□) of 20 μM MccJ25 at 37°C. The same experiment was carried out with the addition of 30 units Mn²⁺-SOD in the absence (▴) and in the presence (▵) of 20 μM MccJ25. The time course reaction was initiated with 10 mM succinate (final concentration). The cytochrome c reduction was followed spectrophotometrically at 550 nm, as described in Materials and Methods.