On the heme-binding capacity of hemopexin

Abstract Hemopexin, a β 1 -globulin from human serum, forms with hemin a red-coloured complex which consists of one mole of hemopexin and one mole of hemin. This complex is stable in the presence of albumin. The composition of the hemopexinhemin complex has been investigated with the aid of spectrophotometric, starch gel and iron analysis. This study has also been concerned with the competition between hemopexin and albumin for the binding of hemin. A tentative evaluation of the hemopexin content of normal human serum has been presented.