The design, synthesis, characterization and exploring the broad spectrum of potency of biologically active molecular building blocks have attracted the attention of scientific community since last couple of decades. The emergence of pathogenic resistance is a natural phenomenon and investigations toward the advances of new structurally diverse inhibitors have always been at the esteem of pharma...

Ammonia emission from animal production is a major environmental problem and has impacts on the animal health and working environment inside production houses. Ammonia is formed in manure by the enzymatic degradation of urinary urea and catalyzed by urease that is present in feces. We have determined and compared the urease activity in feces and manure (a urine and feces mixture) from pigs and ...

Since the discovery of Helicobacter pylori, the urease activity of this bacterial pathogen has been identified as the key factor in infection and acid acclimation in the human stomach. Ureolytic activity plays a key role in the pathogenesis of several bacteria, and urease has also been described as an emerging pathogenic factor during fungal infection. However, urease produced by the oral bacte...

An optical urea biosensor was fabricated by stacking several layers of sol-gelfilms. The stacking of the sol-gel films allowed the immobilization of a Nile Bluechromoionophore (ETH 5294) and urease enzyme separately without the need of anychemical attachment procedure. The absorbance response of the biosensor was monitoredat 550 nm, i.e. the deprotonation of the chromoionophore. This multi-laye...

Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a ur...

A new silica-gel nanospheres (SiO2NPs) composition was formulated, followed by biochemical surface functionalization to examine its potential in urea biosensor development. The SiO2NPs were basically synthesized based on sol-gel chemistry using a modified Stober method. The SiO2NPs surfaces were modified with amine (-NH2) functional groups for urease immobilization in the presence of glutaric a...

The possibility of using disposable plastic-carbon potentiometric sensors as enzyme biosensors was examined. Urease enzyme was immobilized on poly(vinyl chloride) based Hor NH4-selective membranes using cellulose acetate. This approach has resulted in a potentiometric response on changing the pH of the solution or NH4 ion content due to an enzymatic reaction that occurs between urease and urea....

The conversion of urea into ammonium carbonate with the ureaser of the soy bean has proven of value not only in urea determinations but in cases where urea interferes with some chemical manipulation since its removal can be readily accomplished by this enzyme.2 Data relative to the action and behavior of urease under various conditions should prove of value in many connections.3 In our original...

Urease (urea amidohydrolase) is usually found in different bacteria, fungi, algae and plants. It is accountable for the hydrolysis of urea and thus, forming ammonia and carbamate, which is the final step of nitrogen metabolism in living organisms [1,2]. The carbamate intern quickly and spontaneously decomposes, yielding a second molecule of ammonia. These reactions may cause significant increas...

Inducible NO synthase (iNOS) expression and production of NO are both up-regulated with Helicobacter pylori infection in vivo and in vitro. We determined whether major pathogenicity proteins released by H. pylori activate iNOS by coculturing macrophages with wild-type or mutant strains deficient in VacA, CagA, picB product, or urease (ureA(-)). When filters were used to separate H. pylori from ...