uricasa

Uricase, also known as uric acid oxidase, is an enzyme that catalyzes the oxidation of uric acid into allantoin. This reaction is a crucial step in the catabolism of purines in many organisms, including most mammals. However, humans and some other primates lack a functional uricasa enzyme due to genetic mutations. In these species, uric acid is the final product of purine breakdown and can accumulate in the blood, potentially leading to conditions like gout if levels become too high.

The uricasa enzyme is a member of the oxidase family and typically contains a flavin adenine dinucleotide (FAD) cofactor. The reaction it catalyzes involves the consumption of oxygen and the production of hydrogen peroxide and allantoin. Allantoin is a more water-soluble compound than uric acid, making it easier for the body to excrete.

The absence of functional uricasa in humans has led to the development of therapeutic uricasa enzymes, often derived from microbial sources. These recombinant uricasa enzymes are used to treat severe cases of gout and hyperuricemia. By breaking down uric acid in the bloodstream, these enzymes can significantly reduce uric acid levels and prevent the formation of painful urate crystals. However, the use of these therapeutic enzymes can also carry risks, including allergic reactions. The study of uricasa provides insights into purine metabolism and has direct implications for human health and disease management.