Urate oxidase (Aspergillus flavus) (AfUox)

Urate oxidase (uricase) is an enzyme that catalyzes the oxidation of uric acid to 5-hydroxyisourate, which is subsequently converted to allantoin, a highly soluble compound easily excreted by the kidneys (UniProt: Q00511). While most mammals possess this enzyme, humans and higher primates lack a functional gene, leading to higher serum uric acid levels and the potential for gout or tumor lysis syndrome (PubMed: 22133537). Aspergillus flavus urate oxidase (AfUox) is a fungal version of the enzyme used therapeutically to manage severe hyperuricemia. PAT101 (also known as PRX-115) is a specific long-acting recombinant AfUox fused to human serum albumin (rHA) to improve its pharmacokinetic profile and reduce the immunogenicity typically associated with fungal proteins (Protalix Biotherapeutics). By lowering systemic urate levels, this fusion enzyme prevents the crystallization of uric acid in joints and kidneys, providing a potent treatment for hyperuricemia-related pathologies.

Other names

UricaseUrate:oxygen oxidoreductaseRasburicasePRX-115PAT101AfUox-rHAUrate at the active site of Aspergillus flavus urate oxidase within the PAT101 AfUox–rHA fusion enzyme

Enzymatic conversion of uric acid into allantoin, which is significantly more water-soluble than uric acid and is readily excreted by the kidneys.