A homology model of Helicobacter pylori urease was developed by using the crystal structure of urease from Klebsiella aerogenes (EC 3.5.1.5) as a template. The acetohydroxamic acid moiety was docked into the active pocket of the enzyme model, followed by relaxation of the complex by use of molecular dynamics. The resulting conformation was used as a template to construct 24 potential dipeptide ...

AIMS To see whether the activity of omeprazole on Helicobacter pylori is associated with toxicity of strains; to determine whether omeprazole inhibited vacuolisation of cells in culture induced by H pylori cytotoxin and by ureas, and if omeprazole prevented H pylori motility. METHODS Minimal inhibitory concentrations (MICs) of omeprazole were determined for seven cytotoxic and five non-cytoto...

Soybean (Glycine max [L.] Merrill) mutant aj6 carries a single recessive lesion, aj6, that eliminates ubiquitous urease activity in leaves and callus while retaining normal embryo-specific urease activity. Consistently, aj6/aj6 plants accumulated urea in leaves. In crosses of aj6/aj6 by urease mutants at the Eu1, Eu2, and Eu3 loci, F(1) individuals exhibited wild-type leaf urease activity, and ...

The soybean (Glycine max L. [Merrill]) var Itachi has 0.2 to 0.3% the urease activity found in developing embryos of a normal line, Prize. The hydroxyurea sensitivity and pH preference of this basal seed urease indicate that it represents a unique enzyme rather than an unusually low level of the normal seed urease. Itachi's seed urease is less sensitive to hydroxyurea inhibition (65-80% inhibit...

Roots of young soybean (Glycine max [L.] Merr.) plants (up to 25 days old) contain two distinct urease isozymes, which are separable by hydroxyapatite chromatography. These two urease species (URE1 and URE2) differ in: (a) electrophoretic mobility in native gels, (b) pH dependence, and (c) recognition by a monoclonal antibody specific for the seed ("embryo-specific") urease. By these parameters...

Gastric biopsy specimens were taken from 737 patients undergoing upper gastrointestinal endoscopy and assessed for Helicobacter pylori infection. The diagnostic utilities of H. pylori culture (733 patients), detection of urease production (724 patients) and histopathological examination (469 patients) were compared. Since each of these techniques may fail to diagnose patients infected with H. p...

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) with pore size 6 nm as an efficient heterogeneous nanoporous solid acid catalyst exhibited good catalytic activity in the Biginelli-like reaction in the synthesis of spiroheterobicyclic rings with good yield and good recyclability. Spiro-pyrimidinethiones/spiro-pyrimidinones-barbituric acid derivatives were synthesized in a simple and efficient ...

The effect of rebamipide, a novel antiulcer compound, on Helicobacter pylori activated neutrophil dependent in vitro gastric epithelial cell injury was investigated. Luminol dependent chemiluminescence (ChL), which detects toxic oxidants from neutrophils exhibited a 12-fold increase when the bacterial suspension of H pylori was added to the isolated human neutrophils. This change was significan...

In the preceding paper (l), hydroxyurea was shown to be a substrate for urease and to be associated with the development of a marked inhibition of the enzyme during t,he course of the reaction. The lack of significant inhibition during the hydrolysis of urea at equal concentrations suggested that the hydroxylamine formed during hydroxyurea hydrolysis was the responsible agent. The inhibitory ef...