Isolation of a human hepatic ferritin receptor.

A human hepatic ferritin receptor has been isolated from human liver and has been purified using affinity chromatography. An affinity constant of 6.0 x 10(8) moles-1 liter was determined for the ferritin receptor. The molecular weight was estimated to be approximately 53,000 by gel electrophoresis. Binding of ferritin to the receptor coupled to a microparticulate support was specific for human liver ferritin with no binding of rat or porcine ferritin. Binding was unaffected by a 100-fold excess of human transferrin, human asialoorosomucoid and bovine albumin. After treatment of the receptor protein with trypsin, binding was not detected. The human hepatic ferritin receptor may play an important role in the uptake of iron into the hepatocyte in physiological and pathological conditions.