FIG. 5.

Inhibition of toxin binding to HEp-2 cells by exogenous LRP. Wild-type CNF1, CNF2, and ΔN545 were incubated with 20 μg of LRP prior to addition to HEp-2 cells. The data are the averages of two independent experiments performed in triplicate, and the error bars indicate the standard deviation above and below the mean. Data were analyzed by paired, two-tailed t tests, and P values are indicated. The values for wells containing toxin but no anti-CNF1 polyclonal sera served as background controls and were subtracted from all sample values (average background control value, 0.790 ± 0.046).