CYP3A4 Peptide - Middle Region Blocking Peptide

This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases that 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. This enzyme is involved in the metabolism of approximately half the drugs in use today, including acetaminophen, codeine, cyclosporin A, diazepam and erythromycin. The enzyme also metabolizes some steroids and carcinogens. This gene is part of a cluster of cytochrome P450 genes on chromosome 7q21.1. Previously another CYP3A gene, CYP3A3, was thought to exist; however, it is now thought that this sequence represents a transcript variant of CYP3A4. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Feb 2011]

CYP3A4: Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation reactions (e.g. caffeine 8-oxidation, omeprazole sulphoxidation, midazolam 1'-hydroxylation and midazolam 4- hydroxylation) of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. Acts as a 1,8-cineole 2- exo-monooxygenase. The enzyme also hydroxylates etoposide. Belongs to the cytochrome P450 family.

Protein type: Xenobiotic Metabolism - drug metabolism - cytochrome P450; Membrane protein, integral; Cell surface; Xenobiotic Metabolism - drug metabolism - other enzymes; Xenobiotic Metabolism - metabolism by cytochrome P450; Oxidoreductase; Lipid Metabolism - linoleic acid; EC 1.14.14.1; Cofactor and Vitamin Metabolism - retinol

Chromosomal Location of Human Ortholog: 7q21.1

Cellular Component: endoplasmic reticulum membrane; intracellular membrane-bound organelle; cytoplasm; integral to membrane

Molecular Function: enzyme binding; quinine 3-monooxygenase activity; iron ion binding; taurochenodeoxycholate 6alpha-hydroxylase activity; albendazole monooxygenase activity; heme binding; oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen; steroid hydroxylase activity; oxidoreductase activity; oxygen binding; monooxygenase activity; testosterone 6-beta-hydroxylase activity; steroid binding; vitamin D3 25-hydroxylase activity

Biological Process: steroid metabolic process; drug catabolic process; xenobiotic metabolic process; exogenous drug catabolic process; androgen metabolic process; monoterpenoid metabolic process; alkaloid catabolic process; lipid metabolic process; heterocycle metabolic process; drug metabolic process; steroid catabolic process; vitamin D metabolic process