[HTML][HTML] Low pH Activates the Vacuolating Toxin of Helicobacter pylori, Which Becomes Acid and Pepsin Resistant (∗)

M de Bernard, E Papini, V de Filippis, E Gottardi… - Journal of Biological …, 1995 - ASBMB
The protein toxin VacA, produced by cytotoxic strains of Helicobacter pylori, causes a
vacuolar degeneration of cells, which eventually die. VacA is strongly activated by a short
exposure to acidic solutions in the pH 1.5-5.5 range, followed by neutralization. Activated
VacA has different CD and fluorescence spectra and a limited proteolysis fragmentation
pattern from VacA kept at neutral pH. Moreover, activated VacA is resistant to pH 1.5 and to
pepsin. The relevance of these findings to pathogenesis of H. pylori-induced gastrointestinal …