β-glucuronidase
| Β-glucuronidase | ||
|---|---|---|
|
||
| Ribbon / surface model of the dimer with nonaglycoside according to PDB 1BHG | ||
| Properties of human protein | ||
| Mass / length primary structure | 629 amino acids | |
| Secondary to quaternary structure | Homotetramer | |
| Isoforms | Long, short | |
| Identifier | ||
| Gene name | GUSB | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 3.2.1.31 , glycosidase | |
| Response type | hydrolysis | |
| Substrate | β-D-glucuronoside + H 2 O | |
| Products | D-glucuronate + alcohol | |
| Occurrence | ||
| Homology family | Beta-glucuronidase | |
| Parent taxon | Creature | |
| Exceptions | plants | |
β-Glucuronidase (GUSB) is the name for enzymes that split β-glucuronides, i.e. glycosides that are derived from glucuronic acid . This reaction step is indispensable for animals and some bacteria in the breakdown of the substances heme , chondroitin sulfate and keratan sulfate . The enzyme is found in the lysosomes of the liver , spleen and tonsils . Defects in the GUSB gene in humans can cause type 7 mucopolysaccharidosis and play a role in hydrops fetalis .
pathology
In the event of a functional deficiency in β-glucuronidase, there is a hereditary disease , a beta-glucuronidase deficiency, which is known as Sly syndrome and belongs to the mucopolysaccharidoses (type VII).
use
It finds applications in biotechnology as a reporter gene . Their activity can be proven using various methods:
- β-glucuronidase hydrolyzes X-Gluc , producing a blue dye;
- 4-methylumbelliferyl-β- D -glucuronide (MUG) is hydrolyzed to 4-methylumbelliferone (MU), which can be detected by its fluorescence . The rate of turnover of β-glucuronidase can be inferred from the intensity of this fluorescence.
- β-Glucuronidase splits p -nitrophenyl-β- D -glucuronide into glucuronic acid and p-nitrophenol . p -nitrophenol dissociates by a base into p -nitrophenolate, which is colored yellow.
See also
Individual evidence
- ↑ UniProt entry
- ↑ Entry on β-glucuronidase. In: Römpp Online . Georg Thieme Verlag, accessed on December 29, 2014.
- ↑ Mucopolysaccharidosis type 7. In: Orphanet (database for rare diseases).
