SULFATED GLYCOPEPTIDES AND GLYCOSAMINOGLYCAN PEPTIDES ISOLATED FROM INTESTINAL MUCOSAE OF RABBIT

1. 1. Two sulfated glycopeptides and a highly sulfated uronic acid-containing glycosaminoglycan peptide were isolated in an highly pure state from protease-digested mucosal scrapings from either rabbit small intestine or colon. 2. 2. Small intestinal mucosa yielded much more highly sulfated fractions than did colonic mucosa. 3. 3. All the sulfated glycopeptides were similar in having galactose, equimolar ratios of glucosamine and galactosamine, the major carbohydrate components, with fucose and sialic acid in addition. Sulfate, present in each sulfated glycopeptide, had a molar ratio to hexosamine ranging from 0.11 to 0.41; this ratio increased with increasing molarity of eluting salt. 4. 4. The most acidic fraction, highly sulfated uronic acid-containing glycosamino-glycan peptide, contained a large quantity of sulfate and an appreciable quantity of uronic acid, in addition to galactose, hexosamine (glucosamine/galactosamine = 0.5), fucose and peptide. 5. 5. Threonine, proline and serine were the predominant amino acids in all the purified fractions. The results of the alkali treatment suggested that the linkages were through the hydroxyl group of threonine and serine to carbohydrates. 6. 6. All the purified fractions showed dextrorotation. The optical activity and sedimentation coefficient of the corresponding fractions from the two different tissues were similar. © 1969.