Adherence of OppA to HeLa cells in the presence of ATPase inhibitors. OppA (black bars) or P60/P80 as a control (white bars), (0.5 μg OppA/well and 0.3 μg P60/well) were preincubated with 200μM DIDS, suramin, ouabain or oligomycin for 20 min before analyzing in adhesion assay. ATPase activity (A) and adhesion efficiency (B) were measured and depicted in relation to the untreated OppA. OppA (0.5 μg protein) was preincubated with FSBA or MgATP for 20 min and then added to HeLa cells (C). Adherence of OppA to HeLa cells in dependence on supplement concentration was determined as described in Material and Methods. Data represent means of three independent experiments with triplicate samples in each experiment. Statistical analysis was performed by unpaired t-test and statistically significant results designated by *. *P < 0.05, **P < 0.01, and ***P < 0.001.