AskDefine | Define urease

Dictionary Definition

urease n : an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia; is present in intestinal bacteria

User Contributed Dictionary



  1. the enzyme, found in soil bacteria and some plants, that catalyzes the hydrolysis of urea into ammonia and carbon dioxide

Extensive Definition

Urease () is an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia. The reaction occurs as follows:
(NH2)2CO + H2O → CO2 + 2NH3 Urea + Water --urease--> Ammonium Carbonate In 1926 James Sumner showed that urease is a protein. Urease is found in bacteria, yeast and several higher plants.
The multi-subunit enzyme usually has a 3:3 (alpha:beta) stoichiometry with a 2-fold symmetric structure (note that the image above gives the structure of the asymmetric unit, one third of the true biological assembly). An exceptional urease is found in Helicobacter pylori, which combines four of the regular six subunit enzymes in an overall tetrahedral assembly of 24 subunits (\alpha_\beta_). This supra-molecular assembly is thought to confer additional stability for the enzyme in this organism, which functions to produce ammonia in order to neutralise gastric acid. The presence of urease is used in the diagnosis of Helicobacter species.

As diagnostic test

Organisms that produce urease tend to be gastrointestinal or urinary tract pathogens, since urease enables them to neutralize the acid present in these acidic environments.
Urease can be used to remove wine stains from textiles.
Urease-positive pathogens include:
urease in Welsh: Wreas
urease in Danish: Urease
urease in German: Urease
urease in Spanish: Ureasa
urease in Italian: Ureasi
urease in Hebrew: אוראז
urease in Japanese: ウレアーゼ
urease in Polish: Ureaza
urease in Portuguese: Urease
urease in Russian: Уреаза
urease in Finnish: Ureaasi
urease in Ukrainian: Уреаза
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