ABSTRACT
This chapter describes the various ligands binding in human milk and how they compare to ligands in cow’s milk and discusses the possible mechanisms assuring a high uptake of iron from human milk by the infant. It also discusses factors affecting human milk iron concentration as well as other milk sources used in infant feeding. Lactoferrin is a glycoprotein with a molecular weight of 82,400. Similar to transferrin, lactoferrin can bind two ferric ions concomitant with two carbonate or bicarbonate ions and the molecule appears to be the result of a gene duplication resulting in two structurally similar half-molecules. The biochemistry of xanthine oxidase is very complex; the enzyme also exists in a dehydrogenase form, in several isoenzymes, and in “de-sulfo” and “de-molybdo” forms. The milk lipid xanthine oxidase is present in the oxidase form and is structurally and functionally similar to the xanthine oxidase of the endothelial cells of capillaries.
