Sequence and Apoptotic Activity of VacA Cytotoxin Cloned from a Helicobacter pylori Thai Clinical Isolate

Figure 2

Purification and Western blot analysis of VacA. (a)  Purification of H. pylori VacA toxin by Ni²⁺ affinity chromatography. The column was washed with 0.1 M Tris-HCl, pH 8.0, 0.3 M NaCl, 10 mM imidazole (peak a). VacA toxin was eluted with elution buffer (0.1 M Tris-HCl, pH 8.0, 0.3 M NaCl, 100 mM imidazole) (peak b). (b) SDS-PAGE (10% gel) analysis of H. pylori VacA toxin after IMAC purification. Lane M: broad range protein marker; lane 1: flow-through; lane 2: 10 mM imidazole wash; lane 3: 100 mM imidazole elution fraction of the protein. (c) Corresponding Western blot of H. pylori VacA toxin after IMAC purification. Western blot profile of the gel as seen in (a) using anti-VacA antibody on 10% SDS-PAGE. Lane M: broad range protein marker; lane 1: flow-through; lane 2: 10 mM imidazole wash; lane 3: 100 mM imidazole elution fraction of the protein.