FIG. 1.

Secretion of VacA Δ346-347. Wild-type H. pylori strain 60190, an isogenic mutant strain encoding a VacA Δ346-347 protein, and a vacA-null mutant strain (60190 vacA::km) were cultured in brucella broth containing activated charcoal, and proteins in the broth culture supernatants were precipitated with a 50% saturated solution of ammonium sulfate. Proteins were electrophoresed on a 10% SDS-polyacrylamide gel, transferred to a nitrocellulose membrane, and immunoblotted with polyclonal anti-VacA serum. Wild-type VacA and VacA Δ346-347 were each proteolytically processed to yield an 88-kDa protein that was secreted by H. pylori into the broth culture supernatant. WT, wild type.