A recombinant urate oxidase enzyme isolated from a genetically-modified strain of Saccharomyces cerevisae. Urate oxidase catalyzes the oxidation of uric acid to the excretable mebolite allantoin, a molecule that is 5-10 times more water-soluble than uric acid. An enzyme that occurs endogenously in most mammals, urate oxidase is not found in humans. or A drug used to treat high blood levels of uric acid in patients with leukemia, lymphoma, and other types of cancer who are receiving certain types of cancer treatment. It is also being studied in the treatment of other medical conditions. Rasburicase is a type of recombinant enzyme and a type of urate-lowering drug. Also called Elitek and recombinant urate oxidase.