When a transferrin protein loaded with iron encounters a transferrin receptor on the surface of a cell, it binds to it and is consequently transported into the cell in a vesicle. The cell will acidify the vesicle, causing transferrin to release its iron ions. The receptor is then transported through the endocytic cycle back to the cell surface, ready for another round of iron uptake. Each transferrin molecule has the ability to carry two iron ions in the ferric form (Fe3+).

The gene coding for transferrin in humans is located in chromosome band 3q21.

Transferrin levels may be checked in iron deficiency, hemochromatosis and other iron overload disorders.

Immune system

Transferrin are also associated with the innate immune system. Transferrin are found in the mucosa and bind iron, thus creating an environment low in free iron, where few bacteria are able to survive.

Other effects

The metal binding properties of transferrin have a great influence on the biochemistry of plutonium in humans.

Antibodies

Assays