Molybdenum in Biology - An Essential Trace Element

Molybdenum in animals

Molybdenum-containing enzymes catalyze basic metabolic reactions in the nitrogen, sulfur, and carbon cycles. With the exception of the nitrogenase cofactor, molybdenum is incorporated into proteins as the molybdenum cofactor that contains a mononuclear molybdenum atom coordinated to the sulfur atoms of a pterin derivative named molybdopterin. Certain microorganisms can also utilize tungsten in a similar fashion. Molybdenum-cofactor-containing enzymes catalyze the transfer of an oxygen atom, ultimately derived from or incorporated into water, to or from a substrate in a two-electron redox reaction.

Kisker, C., Schindelin, H., Rees, D.C., Molybdenum-cofactor-containing enzymes: Structure and mechanism, Annual Review Of Biochemistry, 1997, 66, 233-267.

Molybdenum is an essential constituent of the enzymes xanthine oxidase and aldehyde oxidase which occur in the livers and intestines of animals, and of hepatic sulfite oxidase. Xanthine oxidase has been isolated from cows' milk. Molybdenum in milk is present mostly in the enzyme, xanthine oxidase; the level is influenced by the level of dietary molybdenum although the level of xanthine oxidase is not

Mills, C. F. and Davis, G. K., Trace elements in Human and Animal Nutrition , Metrz, W. ed., 5th Ed., Academic Press, New York , 1987, 429.