Figure 3

Binding of M. bovis LppA to EBL cell membrane extracts. A rLppA binds to embryonic bovine lung (EBL) cell membrane extracts in a dose-dependent manner. Different concentrations of rLppA (200–0.8 ng) were added to the wells of plates coated with EBL cell membrane extracts (200 ng) and were then incubated with anti-LppA serum for 1 h, followed by incubation with horseradish peroxidase–conjugated goat anti-mouse secondary antibody. Subsequently, after 10 min of incubation with tetramethylbenzidine, bound rLppA was detected by measuring the optical density of the wells at 405 nm using a microtiter plate reader. Bovine serum albumin served as the negative control. B Inhibition of rLppA binding to EBL cell membranes by anti-LppA serum. rLppA (200 ng) was pre-incubated with various concentrations of anti-LppA serum for 1 h and added to wells coated with EBL cell membrane extracts (200 ng). Pre-immune serum was used as the negative control. Values are presented as mean ± standard error of the mean of three independent experiments (*p < 0.05, **p < 0.01, ***p < 0.001).