The peptic zymogens of human gastric mucosa have been studied in the past by three different techniques: phosphate-gradient chromatography on a column of DEAE-cellulose, chloride-gradient chromatography on DEAE-cellulose and agar-gel electrophoresis. These techniques have given different results, each suggesting the presence of a different number of pepsin zymogens in human gastric mucosa. In the present experiments gastric mucosal homogenates were subjected to analysis by all three techniques. The two major zymogen peaks obtained from phosphate-gradient chromatography were found to be composed of the three fractions found on chloride-gradient chromatography; these fractions in turn were shown to be heterogeneous on agar-gel electrophoresis. The latter technique demonstrated the presence of seven separable enzymically active components in human gastric mucosal homogenates. The relationships of the components separated by the three techniques are discussed.
