Figure 6.

Western blot-based identification of the H. ducreyi cdt gene product bound by the H. ducreyi cytotoxin-neutralizing mAb. After isopropyl β-d-thiogalactoside induction, proteins in recombinant E. coli strains carrying genes encoding the His-CDT fusion proteins were resolved by SDS/PAGE and either stained with Coomassie blue (panel 1) or probed in Western blot analysis with the cytotoxin-neutralizing mAb (panel 2). Lanes: A, His-CdtA; B, His-CdtB; C, His-CdtC; D, vector only. The arrows on the right side of each panel indicate the position of the 22-kDa His-CdtC fusion protein that bound the cytotoxin-neutralizing mAb. Size markers (in kDa) are present on the left side of each panel.