Purification and biochemical characteristics of urease from Proteus rettgeri

Magaña-Plaza, I.; Montes, Caroline da Silva; Ruíz-Herrera, José

doi:10.1016/0005-2744(71)90103-3

Cited by 21 publications

(14 citation statements)

References 16 publications

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“…In contrast, crystallization has been less useful for purifying microbial ureases. Urease crystals have been reported for the Providencia rettgeri enzyme; however, only low levels of activity were retained (133).…”

Section: Purification Of Microbial Ureasesmentioning

confidence: 99%

“…Ureases from several sources have been found to be inactivated by heavy metals (15,65,133,138,167) and by oxidation (126,133,137); thus, most purification procedures include low levels (e.g., 1 mM) of ethylenediaminetetraacetate (EDTA) and a thiol such as dithiothreitol or 2-mercaptoethanol to preserve activity.…”

Section: Urease Stabilitymentioning

confidence: 99%

“…Similarly, purified urease from Brewvibacteriiim ammolniagenies (167) and a crude enzyme preparation from Alcaligenes elutrophlus (88) were stable for 10 min in pH 7.5 and 7.0 buffers at temperatures exceeding 50°C. Interestingly, Proi'idencia rettgeri urease was stable to 80°C in the presence of urea, but activity was rapidly lost when substrate was absent (133).…”

Section: Urease Stabilitymentioning

confidence: 99%

“…For a variety of partially purified ureases, most activity was retained after precipitation steps involving acetone (102,123,167,204). In contrast, ethanol crystallization led to low recovery of Providencia rettgeri urease activity (133).…”

Section: Urease Stabilitymentioning

confidence: 99%

“…For comparison, jack bean urease possesses a K,,, of 2.9 mM (14). A range of K,,, values is reported for Bacillus pasteurii (123), Brevibacterium ammoniagenes (167), and Providencia rettgeri (133) because the K,,, was reported to vary with buffer and pH conditions. In contrast, ureases from K. aerogenes (227) and Proteuis miniabilis (21) exhibited nearly pH-independent K,m values from pH 5 to 11 when noninhibitory buffers were used.…”

Section: Kinetic Properties Of Microbial Ureasesmentioning

confidence: 99%

See 4 more Smart Citations

Microbial ureases: significance, regulation, and molecular characterization.

Mobley¹,

Hausinger²

1989

Microbiological Reviews

847

538

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Section: Purification Of Microbial Ureasesmentioning

confidence: 99%

Section: Urease Stabilitymentioning

confidence: 99%

Section: Urease Stabilitymentioning

confidence: 99%

Section: Urease Stabilitymentioning

confidence: 99%

Section: Kinetic Properties Of Microbial Ureasesmentioning

confidence: 99%

See 3 more Smart Citations

Microbial ureases: significance, regulation, and molecular characterization.

Mobley¹,

Hausinger²

1989

Microbiological Reviews

847

538

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Synthesis of chitin by particulate preparations from Aspergillus flavus

López-Romero

Ruíz-Herrera

1976

Antonie van Leeuwenhoek

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Cell-free extracts from Aspergillus flavus catalyzed the synthesis of chitin from UDP-GlcNAc. Most of the activity was associated with membrane-rich fractions whereas no activity was detected in the cell walls. Chitin synthetase was activated by fungal acid proteases; animal and plant proteases destroyed it. Upon incubation at 0 C and 28 C chitin synthetase was inactivated, probably by the action of proteases present in the particulate preparations. Maximal activity was obtained at pH 6.6-7.1 and 15 C. Arrhenius plot showed a biphasic curve with the transition at 7 C. E values were 3300 Kcal/mole above this temperature and 15500 Kcal/mole below it. The enzyme was activated by GlcNAc and required a divalent metal, the most active being Mg++. By plotting v vs UDP-GlcNAc concentration a sigmoidal curve was obtained. Km calculated at high substrate concentrations was 20 mM. Chitin synthetase was competitively inhibited by polyoxin D (Ki 6.5 muM) and (Ki 1.35 mM), the latter giving complex kinetics.

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Purification and properties of urease fromSporobolomyces roseus

Jahns

1995

Antonie van Leeuwenhoek

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Urease (EC 3.5.1.5) catalyses the hydrolysis of urea to ammonia and carbon dioxide. The enzyme from Sporobolomyces roseus was enriched 780-fold and purified to apparent homogeneity using heat treatment, ion exchange chromatography on Q-Sepharose fast flow, hydrophobic interaction chromatography on Phenyl-Sepharose, size exclusion chromatography on Sephacryl S 300 HR, and ion exchange chromatography on MonoQ. Analysis of the purified enzyme by SDS-PAGE demonstrated the presence of subunits with a molecular weight of 90 (+/- 4) kDa. The M(r) of the native enzyme was estimated by size exclusion chromatography to be 340 (+/- 30) kDa, suggesting a tetrameric structure different from other ureases isolated so far from both prokaryotes and eukaryotes. The enzyme was heat-stable, showing no loss of activity after incubation at 70 degrees C for 15 min. The highest urease activities were observed after growth on media containing urea as the sole source of nitrogen.

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Purification and biochemical characteristics of urease from Proteus rettgeri

Cited by 21 publications

References 16 publications

Microbial ureases: significance, regulation, and molecular characterization.

Microbial ureases: significance, regulation, and molecular characterization.

Synthesis of chitin by particulate preparations from Aspergillus flavus

Purification and properties of urease fromSporobolomyces roseus

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