Figure 5. Crystal structure of laminin α2 LG4-5 bound to a matriglycan oligosaccharide.

Matriglycan is a GlcA-Xyl polysaccharide attached to the transmembrane protein dystroglycan [53–56]. A GlcA-Xyl oligosaccharide was synthesized enzymatically using LARGE and soaked into crystals of laminin α2 LG4-5 [65]. The Ca²⁺ ions in LG4 and LG5 are represented as magenta spheres. Disulphide bonds are shown in yellow with sulphur atoms represented as spheres. The oligosaccharide is shown in stick representation, with GlcA and Xyl carbon atoms in light gray and orange, respectively. The arrow indicates the location of heparin-binding residues in the corresponding α1 LG4-5 structure [66].