Description
General description
Subunit molecular weight: ~90,770
Composed of six subunits with total molecular weight: ~544,620
Urease (Ure) enzyme is present in the cytosol. It is active at acidic pH and is expressed at 28°C. Urease binds to nickel and is present in archaea, bacteria, unicellular eukaryotes and plants. Jack bean urease was the first enzyme to be crystallized and the first enzyme found to contain nickel. It is a multi-subunit enzyme, consisting of 91 kDa subunits in three protein forms.
Application
Urease from Canavalia ensiformis (Jack bean) has been used: to spike urine samples to determine the hydrolysis rate of urea in pure urine It has also been used to study the inhibitory action of polyhalogenated benzo- and naphthoquinones on Bacillus pasteurii and Canavalia ensiformis.
Biochem/physiol Actions
In Canavalia ensiformis (Jack Bean), urease facilitates the conversion of L-canavanine to canaline.
Urease is involved in purine metabolism and the urea cycle. It hydrolyze urea to produce ammonia and carbon dioxide.
Other Notes
One micromolar unit will liberate 1.0 μmole of NH₃ from urea per min at pH 7.0 at 25 °C. It is equivalent to 1.0 I.U. or 0.054 Sumner unit (1.0 mg ammonia nitrogen in 5 minutes at pH 7.0 at 20 °C)
