Urease Activity

Author(s): Lívia Maria da C. Silva, Andrea M. Salgado and Maria Alice Z. Coelho

Pp: 292-319 (28)

* (Excluding Mailing and Handling)

Abstract

Urease, a nickel-dependent metalloenzyme, is synthesized by a wide variety of organisms, including plants, bacteria and fungi. It catalyzes the hydrolysis of urea into ammonia and carbon dioxide. Although the amino acid sequences of plant and bacterial ureases are closely related, some biological activities differ significantly. To date, the structural information is available only for bacterial ureases although the enzyme extracted from jack bean (Canavalia ensiformis), which is the best-studied plant urease, had been crystallized in 1926. Tests for urease activity determination should be based on direct or indirect methods and most of the methods utilized for urease detection are based on analysis of its activity in urea hydrolysis. The urease activity determination is extremely important in several areas, mainly in agriculture, medicine and clinical analysis.

Keywords: Urease, metalloenzyme, urea, ammonia, carbon dioxide, canavalia ensiformis, virulence factors, colorimetric test, bromcresol purple, ficoll reagent, nessler, alcalimetric test, pH changes, back-titration, agriculture, clinical test, phenol red, pH indicator, spectrophotometry.