Structure of the complex oligosaccharides of fetuin.

作者：Jacques Baenziger, Dorothy Fiete · 发表于：Journal of Biological Chemistry · 年份：1979 · DOI：10.1016/s0021-9258(17)37874-2 · 被引用次数：252 · 研究领域：Glycosylation and Glycoproteins Research、Carbohydrate Chemistry and Synthesis、Enzyme Structure and Function

The complete structure of the complex oligosaccharides of fetuin has been established. The three fractions of complex oligosaccharide which were isolated by ion exchange chromatography following pronase digestion (F-I, F-II, and F-III) had identical molar ratios of sialic acid (Sia), galactose, mannose, and N-acetylglucosamine of 3:3:3:5. A combination of methylation analyses, Smith periodate degradations, and endoglycosidase and exoglycosidase digestions were utilized to establish the structure which is proposed to be: (see article of journal). Features of this structure not previously established include the presence of 2 residues of alpha2,3- and 1 residue of alpha2,6-linked sialic acid and their location relative to the mannose branch points. Also unusual is the presence of an alpha-linked branch mannose with substituents at positions 2 and 4 which is in turn linked to position 6 of the beta-linked, branch mannose. These features result in unexpected resistance to specific exoglycosidases.