FIGURE 5.

Changes in the sensitivity of E. histolytica to metronidazole by overexpression of EhNOs. A, shown is an immunoblot analysis of EhNOs in the transformants expressing Myc-tagged EhNO1 and -2. Approximately 40 μg of total lysate from the pKT-MR (control), EhNO1 (pKT-MR-NO1), and EhNO2 (pKT-MR-NO2)-overexpressing transformants was electrophoresed on a SDS-PAGE gel under reducing conditions and subjected to immunoblot analysis using anti-EhNO1, anti-EhNO2, anti-Myc, and anti-EhCS1 (control) antibodies. Black and white arrows indicate endogenous and Myc-tagged EhNO1 and -2, respectively. B, susceptibility of transformed trophozoites to metronidazole is shown. Trophozoites (10⁴ cells/ml) were cultivated in the presence of 0–16 μm metronidazole for 48 h, and the number of viable cells was then counted. The percentages of living cells are shown relative to those of unexposed control cells. Error bars represent the S.E. of five independent experiments.