The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by glucocorticoids and some pharmacological agents. The enzyme metabolizes drugs such as nifedipine and cyclosporine as well as the steroid hormones testosterone, progesterone and androstenedione. This gene is part of a cluster of cytochrome P450 genes on chromosome 7q21.1. This cluster includes a pseudogene,<unk> P1, which is very similar to<unk> . This similarity has caused some difficulty in determining whether cloned sequences represent the gene or the pseudogene.<unk> /3A5 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, and xenobiotics. Immunoblot analysis of liver microsomes showed that<unk>  is expressed as a 52.5-kD protein, whereas<unk>  migrates as a 52.0-kD protein. The human<unk> subfamily,<unk> ,<unk> ,<unk>  and<unk> 3, is one of the most versatile of the biotransformation systems that facilitate the elimination of drugs (37% of the 200 most frequently prescribed drugs in the U.S.).<unk>  and<unk>  together account for approximately 30% of hepatic cytochrome P450, and approximately half of medications that are oxidatively metabolized by P450 are<unk> substrates. Both<unk>  and<unk>  are expressed in liver and intestine, with<unk>  being the predominant form expressed in extrahepatic tissues.
CYP3A5
CYP1A2
CYP2C19
CYP2D6
CYP3A4
CYP2C8
CYP2C9
CYP2J2