Title: The carbohydrate-protein linkage in the α1-glycoprotein of human plasma
Abstract: After prolonged digestion with Pronase, over 50% of the carbohydrate of the α1-glycoprotein was isolated as glycopeptide fractions with molecular weight near 1800. One of the fractions yielded asparagine (aspartic acid plus NH3) as the sole amino acid residue. Some of the aspargine had been cleaved from the carbohydrate unit (octasaccharide) by Pronase leaving N-acetylglucosamine in the reducing position. It was proposed that aspargine is joined through its amide group to form a 8-aspartyl N-acetylglucosaminylamine linkage. Some of the asparagine residues of the other fraction appear to be in peptide linkage with threonine which is N-terminal. This report does not concur with the proposal (Winzler and Inoue, 1961) that glutamic acid is joined to the amino group of glucosamine in the α1-glycoprotein. Recently glycopeptides in which aspartic acid predominated were isolated from the α1-glycoprotein (Kamiyama and Schmid, 1962).
Publication Year: 1962
Publication Date: 1962-07-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
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Cited By Count: 43
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