Fig 2.

Lytic activity of TG1 protein against S. aureus. (A) A 5-μg volume of nickel affinity-purified TG1 (30.1 kDa) was resolved on a 15% SDS-PAGE gel in the absence (SDS-PAGE, lane 1) or in the presence (zymogram, lane 2) of S. aureus Sa9 cells. Gels were either stained with Coomassie blue (SDS-PAGE) or incubated in water for 1 h at room temperature (zymogram). Lanes M, standard molecular mass marker in kilodaltons (Prestained SDS-PAGE Standards, broad range; Bio-Rad Laboratories). (B) Representative turbidity reduction assay performed by challenging S. aureus Sa9 cells with 5 μM TG1 for 120 min at 37°C. The light-gray line indicates the untreated cultures (S. aureus Sa9 cells plus MES-NaOH [50 mM], pH 5); the dark-gray line indicates treated cultures (S. aureus Sa9 cells plus 5 μM TG1). (C) Viability test performed by challenging S. aureus Sa9 cells with 5 μM TG1 for 30 min and 1, 2, and 3 h at 37°C (light-gray bars). The dark-gray bars indicate untreated cultures (S. aureus Sa9 plus MES-NaOH [50 mM], pH 5). Error bars represent the means ± standard deviations of the results of two independent assays.