Mucoproteins, paper electrophoresis with

The latter group (M13, M14) separated two types of KIK factor from cancerous gastric juice. The first was a mucopolysaccharide and the second a mucoprotein. Others thought it to be a mucopolypeptide. A similar factor from cancerous ascitic fluid (19) contained 50-60% hexoses, 1.5% tyrosine, and 10% protein by biuret reaction. It formed a single peak at pH range 1.5-10.0 on paper electrophoresis, and at pH 8.6 moved with the mobility of serum y-globulin. 

Wada et al. (W7) studied mucoprotein and mucoproteose fractions by horizontal paper electrophoresis in veronal buffer of pH 8.6 and in acetate buffer of pH 4.5. They processed these materials from gastric juices of normals, patients with histamine-fast anacidity, and those with gastric cancer, which were collected after insulin stimulation. They also subjected the trichloroacetic acid precipitate of gastric juice to electrophoresis, as well as the supernatant fraction remaining after acetone precipitation of the trichloroacetic filtrate of the gastric juice. 

Latner et al. (1954a,b) prepared from a crude concentrate a substance with high intrinsic factor activity without using paper electrophoresis. As far as could be judged by its behavior during electrophoresis and in the ultracentrifuge the material was relatively pure. The molecular weight was about 15,000, and it appeared to be a mucoprotein. 

This material, described by Nakahara and Fukuoka (Nl), is present only in cancer gastric juice. Upon intraperitoneal injection into mice, it depresses the catalase titer of the liver, kidney, and blood. The relationship of this material to mucopolysaccharides and mucoproteins of gastric juice is not well known. Toxohormone— like material obtained from normal stomach which is biologically inactive, however—was found to have lower polarographic activity than that from stomachs with gastric cancer (M18). Separation of materials with toxohormone activity by continuous electrophoresis on paper curtain and column chromatography is discussed in the following review in this volume. 

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