Bifunctional adsorbents for hydrophobic displacement chromatography of proteins

The separation of pancreatic trypsinogen and alpha -chymochypsinogen A by d isplacement chromatography was tested on a bifunctional adsorbent containin g both butyl and carboxymethyl groups. Methacrylic triblock copolymer was s ynthesized and used as the displacer. Compared to the displacement results on commercial Butyl-Sepharose, it was found that both the separation and re covery of trypsinogen and alpha -chymochypsinogen A were improved. Adsorpti on isotherms of proteins were measured on both the commercial Butyl-Sepharo se and the synthesized bifunctional adsorbents. It was found that the impro vement of protein separation on bifunctional adsorbents was attributed to t he alteration of the adsorption of trypsinogen. Charge repulsion between tr ypsinogen and the negatively charged carboxymethyl groups may account for t he alteration. In addition, taking advantage of the effect of charge repuls ion, the column regeneration became much easier on the column packed with b ifunctional adsorbents.