Properties and Biotechnological Applications of β-Glucuronidases

Glucuronic acid is an acid form of glucose, which is obtained by the oxidation of the sixth carbon of the glucose to a carboxylic group. The vital macromolecules that contain glucuronic acid are widely spread in all organisms, for example in animals it is found in the glycocalyx, a glycoprotein coat that covers some cells, and in the proteoglycans which include chondroitin sulfate, heparin, mucoitin sulfate, hyaluronic acid, and intercellular matrix. In human, the balance between glucuronidation and beta-glucuronidase gene (GUSB) plays a pivotal role in the medical applications of GUSB. In plant biotechnology, GUSB gene shows a superior property as a reporter gene; the endogenous GUSB interference may be minimized by using GUSB gene from extremely thermophilic microorganisms, which should have much higher thermostability. Human GUSB is a homotetrameric enzyme that plays an important role in the degradation of Glycosaminoglycans that contain glucuronic acid.