Figure 2. mazEF-Mediated Carbonylation of Cellular Protein Following Treatment by Various Antibiotics.

(A, C, and E) Protein carbonylation. E. coli strains MC4100relA ⁺ (WT) and its derivative MC4100rel A ⁺ΔmazEF (ΔmazEF) were grown in aerobic conditions. Logarithmic cells were pre-incubated as in Figure 1, and treated with antibiotics as follows: (A) rifampicin (20 μg/ml) for 10 min; (C) nalidixic acid (1 mg/ml) for 10 min; (E) trimethoprim (2 μg/ml) for 1h. Protein carbonylation was determined.

(B, D, and F) Relative carbonyl levels of a representative experiment is described in (A, C, and E). The intensity of bands obtained in same time points as in panels (A, C, and E) from three independent experiments was quantified. The numbers express the relative carbonyl levels of each treated strain compared to untreated WT strain.