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Acidic media trigger cytoplasmic urease activity of the unique human gastric pathogen Helicobacter pylori. Deletion of ureI prevents this activation of cytoplasmic urease that is essential for bacterial acid resistance. UreI is an inner membrane protein with six transmembrane segments as shown by in vitro transcription/translation and membrane separation.(More)
ureI encodes an integral cytoplasmic membrane protein. It is present in the urease gene cluster of Helicobacter pylori and is essential for infection and acid survival, but its role is unknown. To determine the function of UreI protein, we produced H. pylori ureI deletion mutants and measured the pH dependence of urease activity of intact and lysed bacteria(More)
Helicobacter pylori infects about 50% of the world's population and inevitably results in the development of gastritis. Of those infected, about 10% develop peptic ulcer disease and roughly 1% develop gastric cancer. Conversely, some take the view that H. pylori infection provides some protection against gastro-esophageal reflux disease and possibly asthma.(More)
Genomic microarray analysis of genes specifically expressed in a pure cell isolate from a heterocellular organ identified the likely K efflux channel associated with the gastric H-K-ATPase. The function of this channel is to supply K to the luminal surface of the pump to allow H for K exchange. KCNQ1-KCNE2 was the most highly expressed and significantly(More)
Pituitary adenylate cyclase-activating polypeptide (PACAP) is known to regulate gastric acid secretion and intestinal motility. In the present study, the pattern of distribution of PACAP and PACAP type 1 receptor (PAC1) immunoreactivities were examined in the rat stomach and distal colon using a specific polyclonal antibody raised against rat/human PAC1.(More)
Enucleated calf and primate eyes were perfused with either p-chloromercuribenzene sulfonate (PCMBS) or p-chloromercuribenzene (PCMB). Both caused a decrease in aqueous outflow that did not result from inhibition of glycolysis in trabecular cells. Morphologic studies of PCMBS-treated primate eyes suggested that the reduction in aqueous outflow occurred as(More)
Glutathione peroxidase was extracted from calf trabecular meshwork. The kinetics of this enzyme were examined, varying the substrates hydrogen peroxide (H2O2), tert- butylhydroperoxide ( tBHP ), and glutathione. The activity of the enzyme in nonpurified homogenates was 596 nmole H2O2 reduced/min/gm wet weight and 680 nmole tBHP reduced/min/gm wet weight(More)
The role of the periplasmic alpha-carbonic anhydrase (alpha-CA) (HP1186) in acid acclimation of Helicobacter pylori was investigated. Urease and urea influx through UreI have been shown to be essential for gastric colonization and for acid survival in vitro. Intrabacterial urease generation of NH3 has a major role in regulation of periplasmic pH and inner(More)
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(More)