The role of Helicobacter pylori urease in opsonization by human complement was investigated. H. pylori wild type strain N6 and isogenic mutants lacking either the large urease subunit (UreB) or an accessory urease protein (UreG) were incubated with different sera. C3b bound to the bacteria was measured by specific staining and flow cytometry. As compared with opsonization of N6 and the UreG-lac...

Major progress has been made both in the field of vaccination and also in therapies against H. pylori infections in recent years. But, the increasing number of H. pylori infections and its resistance to current antibiotics has become a worldwide problem, due to the direct correlation between H. pylori infections and gastritis, gastric ulcers as well as cancer. In this regard, new alternative th...

The urease from the picoplanktonic oceanic Prochlorococcus marinus sp. strain PCC 9511 was purified 900-fold to a specific activity of 94.6 micromol urea min(-1) (mg protein)(-1) by heat treatment and liquid chromatography methods. The enzyme, with a molecular mass of 168 kDa as determined by gel filtration, is the smallest urease known to date. Three different subunits with apparent molecular ...

Secretion of proteins by Helicobacter pylori may contribute to gastric inflammation and epithelial damage. An in vitro analysis was designed to identify proteins released by mechanisms other than nonspecific lysis. The radioactivity of proteins in the supernatant was compared with that of the intact organism by two-dimensional gel phosphorimaging following a 4-h pulse-chase. The ratio of the am...

Previous studies have demonstrated that Helicobacter pylori (Hp) delays its entry into macrophages and persists inside megasomes, which are poorly acidified and accumulate early endosome autoantigen 1. Herein, we explored the role of Hp urease in bacterial survival in murine peritoneal macrophages and J774 cells. Plasmid-free mutagenesis was used to replace ureA and ureB with chloramphenicol ac...

conclusion our findings confirmed that a prokaryotic expression system of rureb229-561 was successfully constructed.the results of sds-page showed that our constructed prokaryotic expression system pet28a- ureb229-561 -bl21de3 efficiently produces target recombinant protein in the form of dissoluble inclusion body. therefore we can suggest that these epitopes can effectively be a vaccine candid...

Antigenic epitopes F8 (SIKEDVQF) and UB-33 (UreB fragment with residues 321-339: CHHLDKSIKEDVQFADSRI) in H. pylori urease that induces neutralizing antibody production were prepared on the cellulose plate from N- to C-terminus using CDMT as a coupling reagent. Reaction of both epitopes with sera of patients with medically confirmed atherosclerosis was studied. Strong, selective reactions of bot...

Infection with candidatus "Helicobacter heilmannii" is associated with gastritis and mucosa-associated lymphoid tissue lymphoma in people. Infection with "H. heilmannii" type 1 predominates (80%) and is thought to be acquired from dogs, cats, or pigs. We further examined the zoonotic potential of dogs and cats by amplifying gastric DNA from cats (n = 45) and dogs (n = 10) with primers against "...

The objective of this study was to determine (i) if complementation of ureB-negative Helicobacter pylori restores colonization and (ii) if urease is a useful reporter for promoter activity in vivo. Strains used were M6, M6DeltaureB, and 10 recombinant derivatives of M6 or M6DeltaureB in which urease expression was under the control of different H. pylori promoters. Mice were orally inoculated w...