The structure of nephritogenoside. A nephritogenic glycopeptide with alpha-N-glycosidic linkage

Nephritogenoside is a glycopeptide with the ability to induce chronic progressive glomerulonephritis (end stage kidney) in homologous animals, by a single footpad injection. This substance contains a novel carbohydrate-peptide linkage, i.e. the trisaccharide (3 glucose residues) chain is alpha-N-glycosidically linked to the polypeptide chain through the amido nitrogen of an asparagine residue at the N-terminal. It was found that the peptide portion of nephritogenoside is composed of twenty-one amino acids (Asn1-Pro-Leu-Phe-Gly5-Ile-Ala-Gly-Glu-Asp10-Gly-Pro-Thr-Gly-Pr o15-Ser-Gly-Ile- Val-Gly20-Gln21) and that the peptide portion has a repeated Gly-X-Y structure.