The aim of the study was to determine the response of soil enzymes such as dehydrogenases, urease and acid and alkaline phosphatases to heating oil contaminating (0.0, 0.25, 0.5, 0.75, 1.0, 1.5% of soil) the experimental soil supplemented with lime and used for cultivation of yellow lupine of the Markiz variety. An increasing contamination of soil with heating oil stimulated the activity of deh...

Title of Document: REGULATION OF ESTUARINE PHYTOPLANKTON AND BACTERIAL UREA UPTAKE AND UREASE ACTIVITY BY ENVIRONMENTAL FACTORS Caroline Miller Solomon, Ph.D., 2006 Directed By: Professor Patricia M. Glibert Marine Estuarine Environmental Science The regulation by environmental factors of two enzymes involved with urea utilization – urea transport and urease – in estuarine phytoplankton and bac...

Proteus mirabilis, a common agent of nosocomially acquired and catheter-associated urinary tract infection, is the most frequent cause of infection-induced bladder and kidney stones. Urease-catalyzed urea hydrolysis initiates stone formation in urine and can be inhibited by acetohydroxamic acid and other structural analogs of urea. Since P. mirabilis urease is inducible with urea, there has bee...

The role in virulence of Actinobacillus pleuropneumoniae urease activity was investigated. A urease-negative mutant was isolated following transposon mutagenesis with a mini-Tn10 derivative. Both the parent strain and the urease-negative mutant exhibited identical LD50 values in a murine infection model. Pig challenge confirmed that the urease-negative mutant was fully virulent, since experimen...

Sonication of Ureaplasma urealyticum cells grown in a dialysate growth medium effectively separated the cytoplasmic fraction from the membrane fraction, with both fractions relatively free from exogenous contaminating proteins. The urease activity was associated with the cytoplasmic fraction, and the ureaplasmal urease exhibited a specific activity higher than that of crystalline jack bean urea...

Urease is a nickel-containing urea hydrolase involved in nitrogen recycling from ureide, purine, and arginine catabolism in plants. The process of urease activation by incorporation of nickel into the active site is a prime example of chaperone-mediated metal transfer to an enzyme. Four urease accessory proteins are required for activation in Klebsiella aerogenes. In plants urease accessory pro...

Ubiquitous soybean urease, as opposed to the seed-specific urease, designates the seemingly identical ureolytic activities of suspension cultures and leaves. It also appears to be the basal urease in developing seeds of a variety, Itachi, which lacks the seed-specific urease (Polacco, Winkler 1984 Plant Physiol 74: 800-804). On native polyacrylamide gels the ureolytic activities in crude extrac...

The important human pathogen Helicobacter pylori requires the abundant expression and activity of its urease enzyme for colonization of the gastric mucosa. The transcription, expression, and activity of H. pylori urease were previously demonstrated to be induced by nickel supplementation of growth media. Here it is demonstrated that the HP1338 protein, an ortholog of the Escherichia coli nickel...

UNLABELLED Urease in Cryptococcus neoformans plays an important role in fungal dissemination to the brain and causing meningoencephalitis. Although urea is not required for synthesis of apourease encoded by URE1, the available nitrogen source affected the expression of URE1 as well as the level of the enzyme activity. Activation of the apoenzyme requires three accessory proteins, Ure4, Ure6, an...