Fig. 1

Structure of hyaluronan. The repeating disaccharide units of N-acetyl-β-D-glucosamine (GlcNAc) and β-D-glucuronic acid (GlcUA) linked via alternating β-1,3 (highlighted in green) and β-1,4 glycosidic bonds (highlighted in red) are shown. The hyaluronidases EC 3.2.1.36 cleave the β-1,3 glycosidic bond, EC 3.2.1.35 the β-1,4 glycosidic bond and the EC 4.2.2.1 the β-1,4 glycosidic bond by elimination, yielding a double bond between carbons 4’ and 5’