xantinfosoxidase

Xantinfosoxidase is an enzyme that catalyzes the oxidation of xanthine to uric acid. It is a molybdenum-containing enzyme found in various organisms, including mammals and bacteria. This enzyme plays a crucial role in purine metabolism, specifically in the final steps of xanthine degradation. In humans, xantinfosoxidase is a homodimer, meaning it consists of two identical subunits. Each subunit contains a molybdopterin cofactor, which is essential for its catalytic activity. The enzyme's active site binds to xanthine, and through a series of redox reactions involving the molybdenum cofactor, it facilitates the conversion to uric acid. This process is important for the excretion of nitrogenous waste products. Genetic defects in xantinfosoxidase can lead to a condition known as xanthinuria, characterized by excessive excretion of xanthine in the urine, which can sometimes lead to the formation of xanthine stones in the kidneys. The enzyme's activity can be influenced by various factors, including pH and the presence of certain inhibitors. In some bacteria, xantinfosoxidase is involved in the metabolism of certain drugs and environmental pollutants. Its presence and function are well-studied in the context of purine catabolism and its implications in human health and microbial biochemistry.