FIG. 4.

Production of TeTx assayed by Western blotting with anti-TeTx antibodies in wild-type C. tetani CN655 (A) and in recombinant strains overexpressing the tetR (CN655-OE) (B), botR/A (CN655-BotR/A) (C), and botR/C (CN655-BotR/C) (D) genes. Supernatants of each culture (OD₆₀₀) were concentrated by trichloroacetic acid precipitation, 20 μg of protein was loaded on lane 1, and serial twofold dilutions were loaded in the subsequent lanes. In panels B and D, the upper bands correspond to the whole TeTx and the lower bands correspond to the H chain.