Glucuronidation

Glucuronidation is the process of elimination of non-polar substances via the liver and kidney by binding to glucuronic acid. Glucuronic acid is a uronic acid, which is produced by double oxidation at carbon -6 (C6) from glucose. The glucuronidation is localized in the endoplasmic reticulum of hepatocytes. Poisons and drugs as well as endogenous substances such as steroid hormones or the bilirubin by binding to glucuronic acid to form glucuronides, which are much more hydrophilic than the auszuscheidende substance itself. The combination of these substances with glucuronic acid is preceded by a UTP - dependent activation reaction which is catalyzed by the enzyme UDP - glucuronosyl transferase, a glycosyltransferase. The resulting product of this reaction is UDP -glucuronic acid, the activated form of glucuronic acid. Without this step, that is, the activation of these uronic acid, the following steps would be endergonic and practically impossible in the cells. Finally can be linked with elimination of the C1 to UDP -1 on the carbon atom (C1) of UDP -glucuronic acid of one of said substrates by a glycosidic linkage with the glucuronic acid.