Separation of human pepsin and gastricsin by affinity chromatography with an immobilized synthetic inhibitor.

Pepsin and gastricsin from human gastric juice were separated by affinity chromatography on Sepharose 4B containing the immobilized synthetic inhibitor of aspartic proteinases, Val-D-Leu-Pro-Phe-Phe-Val-D-Leu. These enzymes were bound to the support at low pH, and gastricsin was released at the same pH with buffer containing 20% dioxan. Pepsin was not released under these conditions, but was eluted at higher pH with buffer also containing 20% dioxan. To obtain perfect separations, it is recommended to use diluted samples. Proteinases from the homogenate of human gastric mucosa are isolated on DEAE-cellulose before separation by affinity chromatography. Pepsin and gastricsin from human gastric juice and human gastric mucosa separated on DEAE-cellulose and isolated by affinity chromatography, were electrophoretically pure.