FIG. 3.

Epitope mapping of the CNF1-neutralizing MAbs JC4, BF8, and NG8 by Western blot analyses with N- and C-terminal CNF1 deletion proteins. (A) Schematic of the CNF1 deletion derivatives used as antigens. The designation of each construct is given on the left, and the deleted portion of the toxin is indicated on the right. (B to D) Immunoblots of E. coli lysates that contained wild-type toxin and either the N- or the C-terminal truncated toxin molecules probed with hybridoma supernatants of MAb JC4 (B), MAb BF8 (C), or MAb NG8 (D). Reactive proteins were detected with appropriate HRP-conjugated secondary antibodies and DAB (MAbs JC4 and NG8) or ECL substrates (MAb BF8).