End point attached heparin affinity matrix

Heparin is a highly sulfated long-chain glycosaminoglycan utilized extensively for its anticoagulation properties, which has found widespread use as a general affinity ligand. The polysaccharide is composed of repeating units of uronic acid and glucosamine with great variability in sequence within the chain. The high degree of sulfation imparts strong acidity to the molecule and it may bond with many compounds simply by ionic interaction. In addition, it has been established that heparin contains certain specific monosaccharide sequences which act as unique binding sites for some proteins. For utilization as a biospecific affinity ligand it has been reported that heparin may optimally be immobilized by a single point of attachment through a terminal sugar residue. This method of immobilization allows unrestricted access to sequences within the polysaccharide chain required for biospecific interaction. Heparin immobilized to beaded agarose by single point attachment through its terminal formyl moiety was prepared. Chromatographic performance characteristics were evaluated using thrombin and antithrombin III as model compounds and elution profiles are presented. Additionally, stability of attachment was directly compared to several other commercially available supports. In conclusion, this end-point attached affinity matrix demonstrates high capacity and good stability compared with that of other methods of preparation.