What is the mechanism of uric acid formation?
Purines from nucleic acids (DNA, RNA) are metabolized to xanthine and hypoxanthine. Xanthine oxidase catalyzes their conversion to uric acid, which is less water soluble, especially in acidic urine.
In other species, urate oxidase catalyzes the conversion of uric acid to the much more soluble allantoin, which is readily excreted by the kidneys.
In humans and higher primates, a missense mutation in the gene encoding urate oxidase occurred during early hominid evolution, and the nitrogenous waste is excreted as uric acid.
