FIGURE 1.

Schematic representation of typical disaccharide repeating units for heparin, ChA, DS, and heparan sulfate. Color coding represents different sugar types, highlighting differences in sulfation (8, 51). The triple sulfated disaccharide unit of heparin (top) makes up 80–90% of the polymer. Heparan sulfate is shown with three saccharides to indicate that the glyco acid is not solely iduronic acid. The glucuronic acid shown here has no sulfate. For the other GAGs, sulfation levels vary between different sources, and the model should be considered an average disaccharide unit.