FIG. 7.

4-POBN-ethanol spin strapping of hydroxyl radical in E. coli and S. pneumoniae. EPR scans of E. coli JI367 (A) and S. pneumoniae R6x (B) incubated with the spin trap, 4-POBN. Scans are normalized to total protein released upon cell lysis. The signals are the average of 10 scans and are representative of four independent determinations. Where indicated, 20 mM DF was preincubated with cells for 5 min, and catalase was added at 1,850 U/ml. For the control, 100 μM FeSO₄ was added to a DETAPAC-free reaction mixture.