Molybdenum: Benefits, Deficiency, and Function as Cofactor

Xanthine oxidase is an enzyme that turns hypoxanthine into uric acid over a series of steps. This enzyme is especially important in the metabolism of purines, which are part of the nucleotides guanosine and adenosine in DNA and RNA. Uric acid functions as an antioxidant in blood but in cells may become an inflammatory prooxidant. This enzyme also will not function without Moco.

Molybdenum Cofactor Deficiency

Earlier in this lesson, it was explained that molybdenum deficiency is extremely rare. One of the scenarios that can cause molybdenum deficiency is a very rare genetic mutation involving the genes that turn molybdenum into Moco. There are two genes involved in transforming molybdenum into Moco: MOS1 and MOS2. Mutations in MOS1 are a type A deficiency, whereas mutations in MOS2 are a type 2 deficiency. The reason why these genes are important is because the molybdenum mineral must be combined with other biological elements to form Moco. When these genetic mutations occur, Moco is still produced but its shape or structure is wrong, so it does not function as a working cofactor. Despite consuming adequate molybdenum in the diet, the body is unable to use molybdenum as a cofactor when there are mutations in MOS1 or MOS2. Because it is from a genetic mutation, a molybdenum cofactor deficiency usually becomes apparent shortly after birth. Symptoms of this disease include neurological dysfunction, seizures, intellectual disability, and coma. Currently, there is an intravenous (IV) treatment for type A deficiency which involves the MOS1 gene. Unfortunately, there is still no treatment for a type B deficiency, which is still being studied.

Lesson Summary

Molybdenum is a trace mineral and an essential nutrient that is needed as a cofactor for enzymatic reactions in the body. Enzymes increase the rate of reactions by reducing the amount of energy needed for those reactions to occur but remain inactive unless they are bound to an enzyme cofactor. Dietary molybdenum is transformed into molybdenum cofactor with the help of certain genes. In its cofactor form, molybdenum is called Moco. Aldehyde oxidase, sulfite oxidase, and xanthine oxidase are three enzymes that require Moco to function. Aldehyde oxidase helps eliminate medications and toxins in the liver. Sulfite oxidase metabolizes sulfur-containing amino acids, turning sulfite into sulfate. Xanthine oxidase breaks purines into uric acid which may function as an antioxidant.

Molybdenum is so plentiful in food and such a small amount is required daily that deficiency is almost unheard of except in cases of a rare genetic mutation that produces nonfunctional Moco. Molybdenum cofactor deficiency causes molybdenum deficiency despite adequate dietary intake, leading to severe neurological dysfunction. Overall, molybdenum is an important mineral that is plentiful and found in animal and plant foods.