Acidic glycopeptides isolated from young human aortas.

Intima-media of young human thoracic aortas were digested with pronase, after extraction of saline-soluble matters and fat. Glycopeptide fractions were separated from the resulting glycoconjugate fractions by fractionation with cetylpyridinium chloride. Acidic glycopeptides (0.15 M Fr and 0.3 M Fr) were then isolated from the glycopeptide fractions by DEAE-Sephadex A-25 (Cl- form) column chromatography. They contained glucosamine, galactose, mannose and sialic acid as the major sugars and glucose as the minor one, although the proportions of these constituents differed from each other. In addition, galactosamine and fucose were the minor sugars in 0.3 M Fr and 0.15 M Fr, respectively. 0.3 M Fr contained much more sulfate and amino acids than 0.15 M Fr. Aspartic acid, proline, glycine, threonine, glutamic acid, valine, serine and alanine were the major amino acids, amounting to 82-89% in total, in these acidic glycopeptides, although their contents differed from each other. It is noteworthy that the proportions of the constituents in the corresponding fractions from young boy and girl with the same age showed similar trend. Although the data indicated the heterogeneity of the carbohydrate and peptide chains of the acidic glycopeptides, the degree of the heterogeneity is smaller than that of sialoglycopeptides isolated previously from aged human aortas.