Occurrence and Structural Analysis of Highly Sulfated Multiantennary N‐linked Glycan Chains Derived from a Fertilization‐Associated Carbohydrate‐Rich Glycoprotein in Unfertilized Eggs of Tribolodon hakonensis

Open Access
Publisher Website
Google Scholar
Abstract
This study represents the first detailed investigation of the nature of highly sulfated (keratan-sulfate-like) complex-type asparagine-linked glycans having a tetraantennary core structure and shows the effectiveness of fast-atom-bombardment mass spectrometric (FAB-MS) methods incorporating derivatization and mild methanolysis for analyzing such complex types of sulfated glycans. The structure of the N-glycan chains was unambiguously established by a combination of compositional analysis, methylation analysis, mild methanolysis for desulfation, hydrazinolysis/nitrous acid deamination, enzymatic (endo-β-galactosidase and peptide: N-glycosidase F) digestions, and instrumental analyses (1H-NMR spectroscopy and FAB-MS) which revealed the novel repeating sulfated carbohydrate sequences, ±Galβ1 → 4Galβ1[→ 4(HSO3→ 6)GlcNAcβ1 → 3(±Galβ1 → 4)Galβ1]n→ (see Structure I; p+q+r+s ≈ 14). This sequence is unique in: (a) the skeletal structure is similar to that of keratan sulfate but is completely devoid of 6-O-sulfated Gal residues and (b) the presence of branched Gal residues in the sequence → 4GlcNAcβ1 → 3(Galβ1 → 4)Galβ1→.

This publication has 52 references indexed in Scilit: