Figure 9.

Action of uricase to catabolize uric acid to allantoin. Uricase (urate oxidase) gene expression and the depicted uricase reaction are lacking in humans, as discussed in the text. PEGylated recombinant uricase preparations are now under investigation for treatment of refractory hyperuricemia in gout, and have the potential to rapidly reduce ("de-bulk") tophus burden.