ABSTRACT
Serum transferrins and lactoferrins deal with different aspects of the metabolism of iron. Serum transferrins transport iron from the bloodstream to the cytosol via recep tor-mediated endocytosis and lose their iron in mildly acidic media [131,132]. In contrast, lactoferrins sequester iron from biological fluids and do not lose it in mildly acidic media [133]. This is assumed to be the result of the higher affinity of lactoferrin for iron compared with that of serum transferrin. The high affinity of lactoferrin for iron is also assumed to be responsible for its different biological function [133].
