The metal ion essential for the activity of xanthine oxidase and xanthine dehydrogenase is

The metal ion essential for the activity of xanthine oxidase and xanthine dehydrogenase is

• A. Molybdenum
• B. Iron
• C. Zinc
• D. Manganese

Answer: (A)

Xanthine oxidase and xanthine dehydrogenase are molybdoenzymes, meaning their catalytic center contains a molybdenum-containing cofactor. This molybdenum cofactor enables the transfer of oxygen during the oxidation steps, allowing hypoxanthine to be converted to xanthine and then to uric acid. While the enzymes also house iron-sulfur clusters and a flavin cofactor for electron transfer, the essential metal driving the catalytic reaction is molybdenum. Other metals like iron, zinc, or manganese aren’t the required catalytic ion for this oxidation.

Xanthine oxidase and xanthine dehydrogenase are molybdoenzymes, meaning their catalytic center contains a molybdenum-containing cofactor. This molybdenum cofactor enables the transfer of oxygen during the oxidation steps, allowing hypoxanthine to be converted to xanthine and then to uric acid. While the enzymes also house iron-sulfur clusters and a flavin cofactor for electron transfer, the essential metal driving the catalytic reaction is molybdenum. Other metals like iron, zinc, or manganese aren’t the required catalytic ion for this oxidation.