Cytochrome P450 1B1 (CYP1B1)

Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway.

It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, retinoid and xenobiotics. Preferentially oxidizes 17beta- estradiol to the carcinogenic 4-hydroxy derivative, and many different procarcinogenic chemicals to their activated forms, such as polycyclic aromatic hydrocarbons.