Affinity chromatography of heme-binding proteins: An improved method for the synthesis of hemin-agarose☆

Abstract Hemin was conjugated to aminoethyl-agarose with high efficiency using 1,1′-carbonyldiimidazole as a condensing agent. The hemin-agarose was an efficient affinity resin for certain heme-binding proteins. It retained 4–5 mg of globin per milliliter of packed gel, whereas hemoglobin did not bind to the resin. The specificity of the adsorbent was further demonstrated by the selective binding of hemopexin from the whole sera of several species of a new heme-binding protein (HBP.93) from rabbit serum. Serum albumin, a major protein in serum which can also bind heme, did not bind to the adsorbent.