Which enzyme is responsible for the conjugation of bilirubin?

The enzyme responsible for the conjugation of bilirubin is UDP-glucuronyl transferase. This enzyme plays a crucial role in the metabolism of bilirubin, a byproduct of heme catabolism. The process of conjugation occurs in the liver, where bilirubin is converted from its unconjugated, lipid-soluble form into a conjugated, water-soluble form by adding glucuronic acid. This transformation is essential for the excretion of bilirubin into bile and subsequently into the intestines, as it prevents the toxic buildup of bilirubin in the body.

This enzymatic action not only facilitates the elimination of bilirubin but also enhances its solubility, enabling it to be excreted through urine and feces. The importance of hormonal balance and liver function is underscored by this process, as any deficiency in UDP-glucuronyl transferase can lead to conditions such as jaundice due to the accumulation of unconjugated bilirubin.

The other enzymes mentioned do not perform the conjugation of bilirubin. β-Glucuronidase is involved in the breakdown of glycosidic bonds in glucuronides and can reverse the conjugation process, which is not the same as facilitating it. Bilirubin