| Structural highlights
4ejj is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| Ligands: | , |
Related: | 3t3r, 3ebs, 2fdy, 1z11, 1z10, 2fdu, 2fdv, 2pg7, 2pg6, 2pg5, 2fdw, 4ejg, 4ejh, 4eji |
Gene: | CYP2A3, CYP2A6 (Homo sapiens) |
Activity: | Unspecific monooxygenase, with EC number 1.14.14.1 |
Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[CP2A6_HUMAN] Exhibits a high coumarin 7-hydroxylase activity. Can act in the hydroxylation of the anti-cancer drugs cyclophosphamide and ifosphamide. Competent in the metabolic activation of aflatoxin B1. Constitutes the major nicotine C-oxidase. Acts as a 1,4-cineole 2-exo-monooxygenase. Possesses low phenacetin O-deethylation activity.[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
Cytochromes P450 (CYP) from the 2A subfamily are known for their roles in the metabolism of nicotine, the addictive agent in tobacco, and activation of the tobacco procarcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Although both the hepatic CYP2A6 and respiratory CYP2A13 enzymes metabolize these compounds, CYP2A13 does so with much higher catalytic efficiency, but the structural basis for this has been unclear. X-ray structures of nicotine complexes with CYP2A13 (2.5 A) and CYP2A6 (2.3 A) yield a structural rationale for the preferential binding of nicotine to CYP2A13. Additional structures of CYP2A13 with NNK reveal either a single NNK molecule in the active site with orientations corresponding to metabolites known to form DNA adducts and initiate lung cancer (2.35 A) or with two molecules of NNK bound (2.1 A): one in the active site and one in a more distal staging site. Finally, in contrast to prior CYP2A structures with enclosed active sites, CYP2A13 conformations were solved that adopt both open and intermediate conformations resulting from an approximately 2.5 A movement of the F to G helices. This channel occurs in the same region where the second, distal NNK molecule is bound, suggesting that the channel may be used for ligand entry and/or exit from the active site. Altogether these structures provide multiple new snapshots of CYP2A13 conformations that assist in understanding the binding and activation of an important human carcinogen, as well as critical comparisons in the binding of nicotine, one of the most widely used and highly addictive drugs in human use.
Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone binding and access channel in human cytochrome P450 2A6 and 2A13 enzymes.,DeVore NM, Scott EE J Biol Chem. 2012 Aug 3;287(32):26576-85. Epub 2012 Jun 14. PMID:22700965[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Maurice M, Emiliani S, Dalet-Beluche I, Derancourt J, Lange R. Isolation and characterization of a cytochrome P450 of the IIA subfamily from human liver microsomes. Eur J Biochem. 1991 Sep 1;200(2):511-7. PMID:1889415
- ↑ Yun CH, Shimada T, Guengerich FP. Purification and characterization of human liver microsomal cytochrome P-450 2A6. Mol Pharmacol. 1991 Nov;40(5):679-85. PMID:1944238
- ↑ Miyazawa M, Shindo M, Shimada T. Roles of cytochrome P450 3A enzymes in the 2-hydroxylation of 1,4-cineole, a monoterpene cyclic ether, by rat and human liver microsomes. Xenobiotica. 2001 Oct;31(10):713-23. PMID:11695850 doi:10.1080/00498250110065595
- ↑ Yano JK, Hsu MH, Griffin KJ, Stout CD, Johnson EF. Structures of human microsomal cytochrome P450 2A6 complexed with coumarin and methoxsalen. Nat Struct Mol Biol. 2005 Sep;12(9):822-3. Epub 2005 Aug 7. PMID:16086027 doi:http://dx.doi.org/10.1038/nsmb971
- ↑ Yano JK, Denton TT, Cerny MA, Zhang X, Johnson EF, Cashman JR. Synthetic inhibitors of cytochrome P-450 2A6: inhibitory activity, difference spectra, mechanism of inhibition, and protein cocrystallization. J Med Chem. 2006 Nov 30;49(24):6987-7001. PMID:17125252 doi:http://dx.doi.org/10.1021/jm060519r
- ↑ DeVore NM, Smith BD, Urban MJ, Scott EE. Key residues controlling phenacetin metabolism by human cytochrome P450 2A enzymes. Drug Metab Dispos. 2008 Dec;36(12):2582-90. Epub 2008 Sep 8. PMID:18779312 doi:10.1124/dmd.108.023770
- ↑ DeVore NM, Scott EE. Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone binding and access channel in human cytochrome P450 2A6 and 2A13 enzymes. J Biol Chem. 2012 Aug 3;287(32):26576-85. Epub 2012 Jun 14. PMID:22700965 doi:http://dx.doi.org/10.1074/jbc.M112.372813
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