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Crystal Structure of Human Drug Metabolizing Cytochrome P450 2C8Crystal Structure of Human Drug Metabolizing Cytochrome P450 2C8
Structural highlights
FunctionCP2C8_HUMAN 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, and xenobiotics. In the epoxidation of arachidonic acid it generates only 14,15- and 11,12-cis-epoxyeicosatrienoic acids. It is the principal enzyme responsible for the metabolism the anti-cancer drug paclitaxel (taxol).[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA 2.7-Angstrom molecular structure of human microsomal cytochrome P450 2C8 (CYP2C8) was determined by x-ray crystallography. The membrane protein was modified for crystallization by replacement of the hydrophobic N-terminal transmembrane domain with a short hydrophilic sequence before residue 28. The structure of the native sequence is complete from residue 28 to the beginning of a C-terminal histidine tag used for purification. CYP2C8 is one of the principal hepatic drug-metabolizing enzymes that oxidizes therapeutic drugs such as taxol and cerivastatin and endobiotics such as retinoic acid and arachidonic acid. Consistent with the relatively large size of its preferred substrates, the active site volume is twice that observed for the structure of CYP2C5. The extended active site cavity is bounded by the beta1 sheet and helix F' that have not previously been implicated in substrate recognition by mammalian P450s. CYP2C8 crystallized as a symmetric dimer formed by the interaction of helices F, F', G', and G. Two molecules of palmitic acid are bound in the dimer interface. The dimer is observed in solution, and mass spectrometry confirmed the association of palmitic acid with the enzyme. This novel finding identifies a peripheral binding site in P450s that may contribute to drug-drug interactions in P450 metabolism. Structure of human microsomal cytochrome P450 2C8. Evidence for a peripheral fatty acid binding site.,Schoch GA, Yano JK, Wester MR, Griffin KJ, Stout CD, Johnson EF J Biol Chem. 2004 Mar 5;279(10):9497-503. Epub 2003 Dec 15. PMID:14676196[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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