Resolution in affinity chromatography. The effect of the heterogeneity of immobilized soybean trypsin inhibitor on the separation of pancreatic proteases.

By affinity chromatography, trypsins and chymotrypsins from mouse pancreas homogenates have been separated using soybean trypsin inhibitor immobilized on Sepharose. The effects of the functional heterogeneity of the adsorbent have been investigated in terms of the resolution obtained. Heterogeneity of the adsorbent have been investigated in terms of the resolution obtained. Heterogeneity has been found to originate from the following sources: heterogeneity of the ligand before immobilization; alteration of the ligand by immobilization; and modification of the ligand after immobilization by molecules to be fractionated. Only when the heterogeneity of the adsorbent was minimized could the resolution of closely related enzyme species be achieved. The elution conditions for different enzymes depended on the amount of enzyme applied, as no complete homogeneity could be obtained. In addition, it was found that the adsorbent was partly degraded by the pancreas extract, reducing its fractionating capacity.