Agarose Derivatives for Purification of Protein by Affinity Chromatography

AFFINITY chromatography1–5, which in principle is related to the use of immunoadsorbants for the purification of antibodies6, exploits the reversible and specific interactions of ligands with macromolecules. Purification is affected by chromatographing the protein to be purified on a column containing an insoluble matrix to which the specific ligand is covalently attached. Beaded agarose (‘Sepharose’) is a useful insoluble support which has recently been used successfully in the selective purification of enzymes1–5,7,9, antibodies and antigens10–15, chemically synthesized peptides16,17, thyroxine binding serum proteins18, and in the study of the interaction of insulin with cell membranes19. In these studies the ligands or peptides were attached through their amino groups after activation of ‘Sepharose’ with cyanogen bromide20,21.