Pepsin, blood group substances from

Fig. 31. Chromatography of normal acid gastric juice oa Amberhte IRC-50 column. The chromatogram of a posthistamine stimulated acid-containing gastric juice specimen from a normal individual. There are 6 protein peaks peak II contains pepsin and peak III, gastricsin. Hexoses are always eluted with peak I, and almost always with peaks IV and V. Blood group substances A and B, when present, are eluted in peak I. From Welsh et al. (Wll).

Chemistry of Tissues. 2. Polysaccharides Showing Blood Group A Specificity and the Nature of the Constituent Units of the Stable Carbohydrate Residue of the A Substance from Pepsin, H. G. Bray, H. H. Henry, and M. Stacey, Biochem. J., 40 (1946) 124-130. 

These have proved invaluable sources of blood group A substances, and many workers have studied the active material isolated from them. Meyer, Smyth and Palmer obtained from hog stomach a polysaccharide which was highly active serologically and contained W-acetyl-D-glucos-amine and D-galactose residues. Landsteiner and his coworkers obtained similar substances from hog stomach and pig pepsin. The following method used for isolating the substance from pepsin is typical. 

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