Carbohydrate-rich compounds in the colonic mucosa of man. III. A preliminary report of some biochemical characteristics of the carbohydrate-rich components in normal colonic mucosa

Preparations of human colonic epithelial cells were obtained virtually free from contamination by connective tissue. A trichloroacetic acid-soluble carbohydrate-rich fraction was prepared after defatting, proteolytic digestion and trichloroacetic acid precipitation of proteins by precipitating the polysaccharides with ethanol and potassium acetate. Four components of acid mucosubstances were revealed on electrophoresis, three of them showing the presence of sulphate radicals. The periodate consumption rate of the preparation was over four times greater after methanolytic desulphation, and confirms previous results concerning the blocking of periodate reactivity by acid radicals. The analysis of the sample showed the presence of 15% protein, 14% hexose, 9% sialic acid, 6% hexosamine, 3% fucose and 3% uronic acid.