Urátoxidáz

Urátoxidáz, also known as uricase or urate oxidase, is an enzyme that catalyzes the oxidation of uric acid to allantoin. This enzyme is found in many organisms, including bacteria, fungi, plants, and some animals, but is notably absent in humans and higher primates. In these organisms, uricase plays a crucial role in the breakdown of purines, a component of nucleic acids. Uric acid is the end product of purine metabolism in humans.

The absence of urate oxidase in humans means that uric acid is not further metabolized and is instead excreted from the body by the kidneys. Elevated levels of uric acid in the blood, known as hyperuricemia, can lead to conditions such as gout, a painful inflammatory arthritis, and kidney stones. In other species that possess urate oxidase, the enzyme efficiently converts uric acid into more soluble and easily excretable allantoin, thus preventing the accumulation of uric acid.

The difference in urate oxidase presence between humans and other mammals has significant implications for medical research and treatment. For instance, pegloticase, a recombinant form of urate oxidase derived from a pig enzyme and modified for human use, is a medication used to treat chronic severe gout in patients who have not responded to other therapies. This therapeutic application highlights the enzyme's role in uric acid metabolism and the potential to address hyperuricemia by introducing exogenous urate oxidase.