Chemoenzymatic synthesis and structural characterization of 2-O-sulfated glucuronic acid-containing heparan sulfate hexasaccharides

Glycobiology. 2014 Aug;24(8):681-92. doi: 10.1093/glycob/cwu032. Epub 2014 Apr 25.

Abstract

Heparan sulfate and heparin are highly sulfated polysaccharides that consist of a repeating disaccharide unit of glucosamine and glucuronic or iduronic acid. The 2-O-sulfated iduronic acid (IdoA2S) residue is commonly found in heparan sulfate and heparin; however, 2-O-sulfated glucuronic acid (GlcA2S) is a less abundant monosaccharide (∼<5% of total saccharides). Here, we report the synthesis of three GlcA2S-containing hexasaccharides using a chemoenzymatic approach. For comparison purposes, additional IdoA2S-containing hexasaccharides were synthesized. Nuclear magnetic resonance analyses were performed to obtain full chemical shift assignments for the GlcA2S- and IdoA2S-hexasaccharides. These data show that GlcA2S is a more structurally rigid saccharide residue than IdoA2S. The antithrombin (AT) binding affinities of a GlcA2S- and an IdoA2S-hexasaccharide were determined by affinity co-electrophoresis. In contrast to IdoA2S-hexasaccharides, the GlcA2S-hexasaccharide does not bind to AT, confirming that the presence of IdoA2S is critically important for the anticoagulant activity. The availability of pure synthetic GlcA2S-containing oligosaccharides will allow the investigation of the structure and activity relationships of individual sites in heparin or heparan sulfate.

Keywords: chemoenzymatic synthesis; heparan sulfate; heparin; oligosaccharides; sulfotransferase.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Carbohydrate Conformation
  • Glucuronates / chemistry
  • Glucuronates / isolation & purification
  • Glucuronates / metabolism*
  • Heparitin Sulfate / biosynthesis*
  • Heparitin Sulfate / chemistry
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Oligosaccharides / biosynthesis*
  • Oligosaccharides / chemistry
  • Sulfotransferases / metabolism*

Substances

  • Glucuronates
  • Oligosaccharides
  • Heparitin Sulfate
  • glucuronic acid 2-sulfate
  • Sulfotransferases