CHARACTERIZATION OF A MONOCLONAL-ANTIBODY AND ITS USE TO PURIFY THE CYTOTOXIN OF HELICOBACTER-PYLORI

The vacuolating cytotoxin (VacA) is a major virulence factor of Helico bacter pylori which is not yet well characterised and is difficult to obtain in large quantities. Here we describe the production of a monoc lonal antibody that recognises the native but not the denatured form o f VacA. The antibody can be efficiently used in affinity chromatograph y for one-step purification of large quantities of VacA from culture s upernatants. Elution at acidic pH dissociates the oligomeric molecule into monomers that reanneal in a time-dependent fashion. The purified cytotoxin is able to bind, and to intoxicate HeLa cells. (C) 1998 Fede ration of European Microbiological Societies. Published by Elsevier Sc ience B.V. All rights reserved.