Urease (None)

Urease is a nickel-containing metalloenzyme that catalyzes the hydrolysis of urea into ammonia and carbon dioxide. It is found in bacteria, fungi, yeast, and higher plants. In pathogenic bacteria, urease neutralizes gastric acid to facilitate colonization. Antibodies against bacterial ureases can be detected serologically and is used as a diagnostic marker for Helicobacter pylori. It also plays a role in autoimmune responses.

Urea binds at the bi-nickel center via its carbonyl oxygen. Nickel ions polarize urea’s carbonyl group. Hydrolysis yields carbamate and ammonia; carbamate spontaneously decomposes into another molecule of ammonia plus CO₂ at physiological pH