Expression and characterization of human cytochrome P450 4F11: Putative role in the metabolism of therapeutic drugs and eicosanoids
Autor: | Yasushi Kikuta, Cheri M. Turman, Auinash Kalsotra, Henry W. Strobel |
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Rok vydání: | 2004 |
Předmět: |
Models
Molecular Chemical Phenomena Leukotriene B4 Molecular Sequence Data Saccharomyces cerevisiae Toxicology Gene Expression Regulation Enzymologic Substrate Specificity chemistry.chemical_compound Cytochrome P-450 Enzyme System Microsomes medicine Humans Amino Acid Sequence Cytochrome P450 Family 4 Pharmacology Binding Sites biology Chemistry Physical Cytochrome P450 Hydroxyeicosatetraenoic acid Metabolism Erythromycin Isoenzymes Kinetics CYP4F11 Pharmaceutical Preparations Biochemistry Eicosanoid chemistry biology.protein Eicosanoids Benzphetamine Drug metabolism medicine.drug |
Zdroj: | Toxicology and Applied Pharmacology. 199:295-304 |
ISSN: | 0041-008X |
Popis: | We previously reported the cDNA cloning of a new CYP4F isoform, CYP4F11. In the present study, we have expressed CYP4F11 in Saccharomyces cerevisiae and examined its catalytic properties towards endogenous eicosanoids as well as some clinically relevant drugs. CYP4F3A, also known as a leukotriene B4 omega-hydroxylase, was expressed in parallel for comparative purposes. Our results show that CYP4F11 has a very different substrate profile than CYP4F3A. CYP4F3A metabolized leukotriene B4, lipoxins A4 and B4, and hydroxyeicosatetraenoic acids (HETEs) much more efficiently than CYP4F11. On the other hand, CYP4F11 was a better catalyst than CYP4F3A for many drugs such as erythromycin, benzphetamine, ethylmorphine, chlorpromazine, and imipramine. Erythromycin was the most efficient substrate for CYP4F11, with a Km of 125 microM and Vmax of 830 pmol min(-1) nmol(-1) P450. Structural homology modeling of the two proteins revealed some interesting differences in the substrate access channel including substrate recognition site 2 (SRS2). The model of CYP4F11 presents a more open access channel that may explain the ability to metabolize large molecules like erythromycin. Also, some wide variations in residue size, charge, and hydrophobicity in the FG loop region may contribute to differences in substrate specificity and activity between CYP4F3A and CYP4F11. |
Databáze: | OpenAIRE |
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