What is the role of xanthine oxidase?

I. The enzyme xanthine oxidase converts hypoxanthine to xanthine and, also, xanthine to uric acid.

II. Xanthine oxidase is involved in purine (nucleotides like adenine, guanine) degradation.

III. In diseases where there is a high production of purines, the enzyme's products (uric acid) can cause gout.

IV. Gout medication is designed to target xanthine oxidase.