Uricase from Arthrobacter globiformis

Research area: Cell Signalling. Uricase is made of four identical subunits and is a homotetrameric enzyme. It is found as a functional uricase in several organisms including, bacteria, archaea, and eukaryotes. Nonetheless, primates and humans lack a functional uricase enzyme.

Uricase from Arthrobacter globiformis has been used for coating the electrodes in - biosensor fabrication for the detection of uric acid in urine samples. It has also been used for analysing the effect of Zn, Cu, Mg, and Mn ions on uricase.

Arthrobacter globiformis is a major producer of uricase or urate oxidase in poultry manure and litter. Uricase hydrolyzes uric acid and causes ammonia volatilization in poultry manure. In the majority of mammals, uricase converts uric acid to allantoin, a soluble excretion product. Humans lack uricase due to its loss during the evolution of hominids. This increases the risk of humans towards gout, kidney stones, hypertension, and diabetes due to increased circulating levels of uric acid.Uricase is an important enzyme that plays a role in the purine metabolic pathway.

Molecular weight: 4 × ~32 KDa (tetramer)
Isoelectric point: is 4.64
K_M value (uric acid as substrate): ~ 0.01 mM
The optimum pH for activity: 8.5-9.5
The optimum pH for stability: 6.0-9.5

Zn and Cu were shown to inhibit the activity of uricase.

One unit will convert 1.0 μmole of uric acid to allantoin per min at pH 9.0 at 25 °C.