Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The stability of native and immobilized urease isolated from Staphylococcus saprophyticus was studied at 4 degrees and 25 degrees C. The activity yield was 20% and 1.4% on the enzyme immobilization in albumin gel and latex membrane, respectively. Inactivation of native microbial urease proceeded 10 times slower in the solution containing 1 mM EDTA and 30 mM sodium sulfite. This solution contributed to a great extent to stabilization of immobilized urease both during storage in the phosphate buffer solution and in case of lyophilization.
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PMID:[Stabilization of native and immobilized urease]. 361 80

We have purified urease from the Mollicutes, Ureaplasma urealyticum, using high performance liquid chromatography methods and DEAE-Sephadex chromatography. While only small amounts of material could be utilized in these methods, urease was purified at least 180-fold, yield a major band on SDS-PAGE of 66,000 daltons, a minor band of 64,000 daltons, and several faint bands of lower molecular mass. These results suggest that the 380,000 dalton intact urease is a pentamer or hexamer of these two larger subunits. The highly purified urease from DEAE-Sephadex retained full activity for at least 20 days at 4 degrees C in sodium phosphate buffer (pH 7.2) with 1% bovine serum albumin. The estimated specific activity of the DEAE peak fractions, 180 IU/micrograms, is at least 90-fold greater than that of jack bean urease.
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PMID:Purification of urease from Ureaplasma urealyticum. 369 Apr 18

In the several strains of Ureaplasma urealyticum that we examined, all originally isolated from human sources, the ureases were found to have a pH optimum between 7.2 and 7.5, and the Km was approximately 2.5 mM urea. Using nonreducing, nondenaturing conditions for polyacrylamide gel electrophoresis, the molecular weight of the holoenzyme was determined to be approximately 380 000. Treatment with reducing agents did not affect the electrophoretic mobility and, therefore, the molecular weight of ureaplasma urease. Immunoblot analysis (using antiserum to U. urealyticum urease) after sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing, denaturing conditions revealed two antigenically reactive bands of molecular weight 174 000 and 179 000. Under reducing, denaturing conditions, a single band of molecular weight approximately 179 000 was detected. Multiple forms of urease were detected by isoelectrofocusing but not by zonal electrophoresis.
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PMID:Properties of urease from Ureaplasma urealyticum: kinetics, molecular weight, and demonstration of multiple enzyme isoelectric point forms. 373 Sep 58

The tryptophan uptake into forebrain and brainstem was measured in urease-injected rats and in controls after prior application of sodium benzoate or hippurate. Benzoate led to an increased brain uptake index of tryptophan. This effect was additive to the increase in tryptophan uptake effected by the provoked hyperammonemia. In contrast, hippurate did not alter tryptophan uptake across the blood-brain barrier. We conclude that benzoate should be monitored especially when applied intravenously to patients with hyperammonemic coma.
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PMID:Brain uptake of tryptophan in urease-injected hyperammonemic rats after treatment with benzoate or hippurate. 377 87

Fourteen of 21 strains isolated from stools, urine specimens and the hospital environment were identified as Kluyvera. All of these 14 strains corresponded with the literary description of the genus Kluyvera and were identical with two reference strains except that one of them failed to utilize sodium acetate within 7 days. One strain (No. 23441) produced massive growth on Jordan's tartrate, which some Kluyvera do. Important in differentiating indole- and Simmons' citrate-negative Kluyvera strains from Escherichia vulneris (two other of our 21 strains) is negative ornithin decarboxylase and negative Christensen citrate in the latter. Three strains were identified as Citrobacter, where especially indole-positive and urease-negative strains may be reminiscent of Kluyvera. An aberrant strain, No. 25115, which alone failed to grow at 42 degrees C and by some characters differed from Kluyvera, E. vulneris and Enteric Group 10, was identified as E. coli.
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PMID:First strains of the genus Kluyvera in Czechoslovakia. 406 Sep 23

The fate of bacteria in human urine was studied after inoculation of small numbers of Escherichia coli and other bacterial strains commonly implicated in urinary tract infection. Urine from normal individuals was often inhibitory and sometimes bactericidal for growth of these organisms. Antibacterial activity of urine was not related to lack of nutrient material as addition of broth did not decrease inhibitory activity. Antibacterial activity was correlated with osmolality, urea concentration and ammonium concentration, but not with organic acid, sodium, or potassium concentration. Between a pH range of 5.0-6.5 antibacterial activity of urine was greater at lower pH. Ultrafiltration and column chromatography to remove protein did not decrease antibacterial activity. Urea concentration was a more important determinant of antibacterial activity than osmolality or ammonium concentration. Increasing the urea of a noninhibitory urine to equal that of an inhibitory urine made the urine inhibitory. However, increasing osmolality (with sodium chloride) or increasing ammonium to equal the osmolality or ammonium of an inhibitory urine did not increase antibacterial activity. Similarly, dialysis to decrease osmolality or ammonium but preserve urea did not decrease inhibitory activity. Decreasing urea with preservation of ammonium and osmolality decreased antibacterial activity. Removal of ammonium with an ion exchanger did not decrease antibacterial activity, whereas conversion of urea to ammonium with urease and subsequent removal of the ammonium decreased antibacterial activity. Urine collected from volunteers after ingestion of urea demonstrated a marked increase in antibacterial activity, as compared with urine collected before ingestion of urea.
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PMID:Antibacterial activity of human urine. 487 82

A urease color test fluid medium (U-9) for the detection and identification of T (T-strain) mycoplasmas in clinical material is described which is sensitive and specific for this group of mycoplasmas. The medium was prepared from commercially available components and contained 95% half-strength, tryptic digest broth (pH 5.5), 4% unheated horse serum, 0.05% highest-purity urea, 0.001% sodium phenolsulfonphthalein, and 1,000 units of potassium penicillin G per ml. The final reaction of medium U-9 was pH 6.0. The overall agreement (positive and negative) between urease reactions in U-9 urease color test medium and culture findings in a standard agar primary culture system among 686 clinical specimens was 98.1%. The disagreement consisted of 13 false-positive urease reactions which were recognized visually as false-positive reactions due to other microorganisms. For specimens from the female genitourinary tract, the inclusion of 2.5 mug of amphotericin B (Fungizone) per ml of medium U-9 is recommended for the suppression of growth of Candida species and filamentous fungi.
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PMID:Urease color test medium U-9 for the detection and identification of "T" mycoplasms in clinical material. 492 43

The effect of diphenyl hydantoin, (DPH) a nonbarbituate anticonvulsant drug, on chromosomes and fertility was tested in cultured human lymphocytes, mouse fertility, and rat maternal marrow chromosomes and fetal development. Whole human blood from 5 male and 5 female subjects was cultured for 68 hours with phytohemagglutinin, then incubated for 2 hours in isotonic salts with .05-.3 mg per ml DPH, .02 mcg per ml colchicine, or .4 mg per ml sodium diethylbarbiturate. The mean number of metaphases per 1000 stimulated cells was 10.0 in controls, 40.3 with colchicine, 27.9 with diethylbarbiturate, and 30.5 with .25 mg DPH per ml. Both diphenylbarbiturate and DPH produced linear dose effect curves. These results were demonstrated not to be due to urea, since there were no differences in urea content, with a 2 hour urease micromethod. Mouse fertility was totally inhibited in 6 virgin mice given .1mg DPH daily for 10 days compared to 41 pups both of 6 control mice. In 6 pregnant rats given 25 mg DPH per 100 gm/orally 4 times daily for 2 days on gestation Days 7 and 8, there were 5 rats with all fetuses resorbed and 1 rat with 3 living and several resorptions. 6 controls had 6-14 normal fetuses each. 50 metaphase plates from each rat's femoral marrow and each fetus were examined 2 hous after injecting .3 mg colchicine per 100 gm. 30% of the metaphase cells from treated females and fetuses showed strongly contracted chromosomes and reduced number os "pulverized" chromosomes. These phenomena may have been due to inhibition by DPH of folic acid metabolism which is involved in purine synthesis.
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PMID:[Action of diphenylhydantoin on chromosomes]. 499 34

1. Urease of specific activity 160-180 Sumner units/g. (Sumner, 1951) was purified from jack-bean meal. The preparation was pure on the basis of polyacryl-amide-gel electrophoresis and N-terminal studies. 2. By using both the 1-fluoro-2,4-dinitrobenzene method and the phenyl isothiocyanate method a single N-terminal methionine residue was found. 3. A single C-terminal sequence -Tyr-Leu-Phe was found by studies with carboxypeptidase A, carboxypeptidase B and hydrazinolysis. 4. N-Bromosuccinimide cleavage showed that five unique tryptophan sequences were present: Trp-Ala, Trp-Glu, Trp-Gly, Trp-Met and Trp-Arg. 5. Polyacrylamide-gel electrophoresis in sodium dodecyl sulphate showed that urease had a subunit molecular weight of 76000. 6. The yield of N- and C-terminal amino acids, the number of tryptic peptides and tryptophan sequences and the above polyacrylamide-gel electrophoretic measurement all suggest that urease contains a single structural subunit of molecular weight 75000.
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PMID:The subunit structure of jack-bean urease. 538 87

The effect of varying concentrations of either NaCl or Na2CO3 (0, 10, 20, and 25 meq/100 g soil) and organic carbon (0 and 2% starch) on the activity of dehydrogenase, urease, and phosphatase (nuclease) was studied in incubated samples of alluvial clay and calcareous sandy loam soils. Moisture content was kept at 60% W.H.C. The level of 10 meq/100 g soil of either sodium chloride or sodium carbonate was stimulatory for the activity of the three enzymes studied in both soils tested. The increasing concentrations of Na2CO3 showed greater changes in the enzymatic activity than the corresponding concentrations of NaCl in both soils. Application of starch reduced the inhibitory effect of the high levels of such salts on the enzymatic activities in both soils, except for phosphatase which was depressed by Na2SO3 in starch-amended soil samples. The calcareous soil responded to the starch addition less than the alluvial soil.
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PMID:Activity of enzymes in organic carbon-amended soils treated with varying levels of salts. 628 41


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