Beta-glucuronidases are members of the glycosidase family of enzymes that catalyse breakdown of complex carbohydrates. Human β-glucuronidase is a type of glucuronidase that catalyses hydrolysis of β-D-glucuronic acid residues from the non-reducing end of mucopolysaccharides, such as heparan sulfate. In human gut β-glucuronidase converts conjugated bilirubin to the unconjugated form for reabsorption.

• Gene ID: 2990
• Gene symbol and aliases: GUSB
• Uniport number: P08236
• GHS symbol(s): GHS07, GHS08
• Signal word: danger

β-Glucuronidases are routinely used for the enzymatic hydrolysis of glucuronides from serum plasma and other fluids prior to analysis by enzyme immunoassay, mass spectrometry, gas chromatography, high performance liquid chromatography, or other means. It is used as a reporter gene in GUS assays to monitor gene expression.

β-Glucuronidase from Helix pomatia is a mixture of enzymes. Inhibitors: D-glucuronic acid, D-galacturonic acid, D-glucaro-1, 4-lactone.

Unit definition: Amount that liberates 1,0 µg of phenolphthalein from phenolphthalein glucuronide per hour at pH 5,0 and 37 °C.