Urate oxidase, recombinant

Rasburicase is a recombinant urate oxidase that catalyzes the conversion of uric acid to allantoin which possesses a greater water-solubility than uric acid. In contrast to allopurinol, rasburicase has also an inhibitory effect on... 

Recombinant urate oxidase catalyzes enzymatic oxidation of uric acid... 

Uricolytics. Nonprimates are able, via the enzyme urate oxidase, to metabolize uric acid to allantoin, a product with better water solubility and faster renal elimination. Ras-buricase, a recombinant urate oxidase, can be given by infusion in patients with malignant neoplasias, in whom chemotherapy is liable to generate a massive amount of uric acid. 

Rasburicase is a recombinant urate-oxidase enzyme produced by a geneticaiiy modified Saccharomyces cerevisiae strain, it is a tetrameric protein with identicai subunits of a moiecuiar mass of about 34 kDa. The moiecuiar formuia of the monomer is C1523H2383N4170462S7. The monomer, made up of a singie 301 amino acid poiypeptide chain, has no intra- or interdisuifide bridges and is /V-terminai-acetyiated. 

Pui CH, Jeha S, Irwin D, Camitta B, et al. Recombinant urate oxidase (rasburicase) in the prevention and treatment of malignancy-associated hyperuricemia in pediatric and adult patients results of a compassionate-use trial. Leukemia 2001 15 1505-1509. 

Pui CH, Mahmoud HH, Wiley JM, et al. Recombinant urate oxidase for the prophylaxis or treatment of hyperuricemia in patients with leukemia or lymphoma. J Clin Oncol 2001 19 697-704. 

Bosly A, Sonet A, Pinkerton CR, et al. Rasburicase (recombinant urate oxidase) for the management of hyperuricemia in patients with cancer report of an international compassionate use study. Cancer 2003 98 1048-1054. 

Fasturtec (Elitex in US rasburicase recombinant urate oxidase produces in S. cerevisiae) Sanofi-Synthelabo hyperuricaemia 2001 (EU), 2002 (US)... 

Germany rasburicase enzyme Fasturtec Elitek Recombinant urate oxidase produced in a Saccharomyces cerevisiae fermentation Anti- hyperuricemia... 

Rasbnricase (Elitek) is a recombinant urate-oxidase that catalyzes the enzymatic oxidation of uric acid into the sol-nble and inactive metabolite allantoin. It has been shown to lower nrate levels more effectively than allopurinol. It is indicated in the initial management of elevated plasma nric acid levels in pediatric patients with leukemia, lymphoma, and solid tumor malignancies who are receiving anticancer therapy expected to result in tumor lysis and significant hyperuricemia. 

ATLS is potentially a catastrophic complication of chemotherapy in patients with a high tumour load. It results from cytotoxic damage to large numbers of cancerous cells. The DNA and RNA released are broken down to uric acid, which precipitates in the renal tubules causing acute uric acid nephropathy. Recent evidence suggests that recombinant urate oxidase, which converts uric acid to soluble allan-toin, is successful in the treatment and prevention of ATLS in patients with haematological malignancies. 

Pharmacologic prevention strategies for tumor lysis syndrome are aimed at low- and high-risk patients (Fig. 96-7). Allopurinol is a xanthine oxidase inhibitor that is used for prevention only because it has no effect on preexisting elevated uric acid. Rasburicase is a recombinant form of urate oxidase that is useful for both prevention and treatment but is extremely expensive (Table 96-12). Although the approved dose is 0.2 mg/kg per day... 

Rasburicase is a recombinant form of an enzyme, urate oxidase. This enzyme catalyses the conversion of uric acid to allantoin, a more soluble molecule, easily cleared by kidney. Monthly infusions of rasburicase appear to be a possible therapy for severe gout not treatable by other means. The most important adverse events are allergy and the development of antibodies which compromise rasburicase effectiveness. 

Reagent 8 has been used in the PEGylation of ribonuclease and superoxide dis-mutase [39], doxorubicin [44], recombinant mammalian urate oxidase [45], uricase [46] and lysozyme [47]. However, it has been reported that PEGylations with reagent 8 leave lipophilic toxic impurities on the conjugated material and thus the use of this derivative is now limited. 

---