Colonization by Helicobacter pylori partly depends on acid-dependent adherence by urease to gastric mucin. To further verify the relevance of urease adherence to colonization, the influence of acidity on the binding sites of H. pylori urease was investigated. When enzyme-based in vitro ligand capture assays were used, the effect of acidity on the binding site of H. pylori urease was determined ...

Klebsiella aerogenes UreE, a metallochaperone that delivers nickel ions during urease activation, consists of distinct "peptide-binding" and "metal-binding" domains and a His-rich C terminus. Deletion analyses revealed that the metal-binding domain alone is sufficient to facilitate urease activation. This domain was purified and shown to exhibit metal-binding properties similar to those of UreE...

In Chenopodium album, leaf excision and light both increase urease (EC. 3.5.1.5) activity. Dithiothreitol (DTT), reduced glutathione (GSH), cysteine and diazoinedicarboxylic acid bis(N,N-dimethylamide) (diamide) activated the crude enzyme. In contrast, crude urease was inhibited by phenylmethylsulphonyl fluoride (PMSF) and Na-p -tosyl-L-lysine chloromethyl ketone HCl (TLCK), suggesting the pres...

BACKGROUND The inhibitory effect of andrographolide sodium bisulphite (ASB) on jack bean urease (JBU) and Helicobacter pylori urease (HPU) was performed to elucidate the inhibitory potency, kinetics and mechanism of inhibition in 20 mM phosphate buffer, pH 7.0, 2 mM EDTA, 25 °C. METHODS The ammonia formations, indicator of urease activity, were examined using modified spectrophotometric Berth...

Urease is a metalloenzyme essential for the survival of Helicobacter pylori in acidic gastric environment. Maturation of urease involves carbamylation of Lys219 and insertion of two nickel ions at its active site. This process requires GTP hydrolysis and the formation of a preactivation complex consisting of apo-urease and urease accessory proteins UreF, UreH, and UreG. UreF and UreH form a com...

Baicalin (BA) is the principal component of Radix Scutellariae responsible for its pharmacological activity. In this study, kinetics and mechanism of inhibition by BA against jack-bean urease were investigated for its therapeutic potential. It was revealed that the IC₅₀ of BA against jack-bean urease was 2.74 ± 0.51 mM, which was proved to be a competitive and concentration-dependent inhibition...

in this work, the structural and electronic properties of folic acid molecule on functionalized (7,0)zigzag single-walled carbon nanotube was studied in gas phase on the basis of density functionaltheory (dft). furthermore, covalent interaction of folic acid with single-walled carbon nanotube wasinvestigated and its quantum molecular descriptors and binding energies were calculated. the dftb3ly...

In this work, the structural and electronic properties of folic acid molecule on functionalized (7,0)zigzag single-walled carbon nanotube was studied in gas phase on the basis of density functionaltheory (DFT). Furthermore, covalent interaction of folic acid with single-walled carbon nanotube wasinvestigated and its quantum molecular descriptors and binding energies were calculated. The DFTB3LY...

Water-insoluble enzyme derivatives possessing specific catalytic activity may provide a useful tool in biochemical studies, since they can readily be removed from the reaction mixture and can be used for the preparation of columns with enzymatic activity. The conversion of several enzymes into the corresponding water-insoluble derivatives by their binding via covalent bonds to insoluble carrier...

The Helicobacter pylori ureE gene product was previously shown to be required for urease expression, but its characteristics and role have not been determined. The UreE protein has now been overexpressed in Escherichia coli, purified, and characterized, and three altered versions were expressed to address a nickel-sequestering role of UreE. Purified UreE formed a dimer in solution and was capab...