The influence of urease activity on N distribution and losses after foliar urea application was investigated using wild-type and transgenic potato (Solanum tuberosum cv Désirée) plants in which urease activity was down-regulated. A good correlation between urease activity and N urea metabolism (NH3 accumulation) was found. The general accumulation of ammonium in leaves treated with urea indicat...

Urease from jack bean meal and hydrated seeds has been obtained in 25 to 33% yield with specific activity in the range of 1000 to 1070 units/mg protein. A purification of 100 to 130-fold was achieved from meal and fully soaked seeds. Use of beta-mercaptoethanol and EDTA was found essential to obtain this high yield and purity. Amino acid analysis showed all 18 amino acids commonly found in prot...

Mutation at either of two genetic loci (Eu2 or Eu3) in soybean (Glycine max [L.] Merr.) results in a pleiotropic elimination of the activity of both major urease isozymes. Surprisingly, the phenotype of a phylloplane bacterium, Methylobacterium mesophilicum, living on the leaves of eu2/eu2 or eu3-e1/eu3-e1 mutants is also affected by these plant mutations. The bacteria isolated from leaves of t...

Catalytic buffering is an advanced method of pH control for the enzyme-based Advanced Catalytic Enzyme System (ACES) and oxidative surety agent decontamination technologies. Ammonia production from urea by urease neutralizes the production of Oalkylphosphonic acids resulting from the hydrolysis of Nerve agents such as Sarin and VX. Fluoride production from Sarin hydrolysis inhibits native ureas...

A novel method for the rapid modification of fullerene for subsequent enzyme attachment to create a potentiometric biosensor is presented. Urease was immobilized onto the modified fullerene nanomaterial. The modified fullerene-immobilized urease (C60-urease) bioconjugate has been confirmed to catalyze the hydrolysis of urea in solution. The biomaterial was then deposited on a screen-printed ele...

Urease is an important virulence factor from Helicobacter pylori that enables bacterial colonization of human gastric mucosa. Specific inhibition of urease activity can be regarded as a promising adjuvant strategy for eradication of this pathogen. A group of organophosphorus inhibitors of urease, namely, aminophosphinic acid and aminophosphonic acid derivatives, were evaluated in vitro against ...

Nickel-containing urease from Klebsiella aerogenes requires four accessory proteins for proper active site metalation. The metallochaperone UreE delivers nickel to UreG, a GTPase that forms a UreD/UreF/UreG complex, which binds to urease apoprotein via UreD. Prior in silico analysis of the homologous, structurally characterized UreH/UreF/UreG complex from Helicobacter pylori identified a water ...

The enzymatic activity of Helicobacter pylori's urease neutralises stomach acidity, thereby promoting infection by this pathogen. Urease protein has also been found to interact with host cells in vitro, although this property's possible functional importance has not been studied in vivo. To test for a role of the urease surface in the host/pathogen interaction, surface exposed loops that displa...

Importance of urease activity on pathogenic differences among Brucella species was evaluated. In cell-free extracts, the B. suis urease showed 12 times greater specific activity than the B. melitensis urease. When Fisher-344 rats were inoculated intraperitoneally (IP), at 1 week post-inoculation (PI), B. melitensis wild type 16 M was recovered from spleens and livers in greater numbers than B. ...