Beta-glucuronidase (GUSB) hydrolyses glucuronate from the HA disaccharides Authored: Jassal, B, 2012-03-16 EC Number: 3.2.1.31 Edited: Jassal, B, 2012-03-16 Pubmed11568288 Pubmed3468507 Reactome Database ID Release 432162226 Reactome, http://www.reactome.org ReactomeREACT_120758 Reviewed: D'Eustachio, P, 2012-03-28 The tetrameric lysosomal enzyme beta-glucuronidase hydrolyses glucuronate from the HA disaccharide (Oshima et al. 1987) resulting in the single sugars glucuronic acid and N-acetylglucosamine. These single sugars can exit the lysosome by an unknown mechanism. L-aspartic acid is an inhibitor of enzyme activity (Kreamer et al. 2001).