Cytotoxicity of LF proteins to RAW264.7 cells.

<p>RAW264.7 cells were incubated with various concentrations of LF-HMA, LF-A, and LF-A/X proteins (A) or LF proteins with mutated N-termini (B) and a fixed concentration of PA (250 ng/ml). Cell viability was assessed at 3 h. Percent viability was calculated relative to cells treated with medium (no toxin).