<haematology, protein> A protein that carries iron in the bloodstream (80 kD) found in mammalian serum, a beta globulin.

Binds ferric iron with a Kass of around 21 at pH 7.4, 18.1 at pH 6.6. An important constituent of growth media.

Transferrin receptors on the cell surface bind transferrin as part of the transport route of iron into cells.

The percentage of transferrin that has iron bound to it is increased in situations of iron overdose and in the disease haemochromatosis. Serum transferrin is decreased in cases of protein deficiency.

(17 Mar 1998)