Expression and Functional Characterization of Breast Cancer-Associated Cytochrome P450 4Z1 inSaccharomyces cerevisiae
| Autor: | Katherine A. Sitko, Allan E. Rettie, Maitreya J. Dunham, Rheem A. Totah, Byron Gallis, Abhinav Nath, John P. Kowalski, Lorela Paco, Sutapa Ray, Matthew G. McDonald, Douglas M. Fowler, Clara J. Amorosi |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Pharmacology chemistry.chemical_classification biology Metabolite Saccharomyces cerevisiae Pharmaceutical Science Cytochrome P450 biology.organism_classification Lauric acid Hydroxylation 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology 0302 clinical medicine Enzyme chemistry Biochemistry 030220 oncology & carcinogenesis biology.protein Heme Cytochrome P450 Family 4 |
| Zdroj: | Drug Metabolism and Disposition. 45:1364-1371 |
| ISSN: | 1521-009X 0090-9556 |
| Popis: | CYP4Z1 is an "orphan" cytochrome P450 (P450) enzyme that has provoked interest because of its hypothesized role in breast cancer through formation of the signaling molecule 20-hydroxyeicosatetraenoic acid (20-HETE). We expressed human CYP4Z1 in Saccharomyces cerevisiae and evaluated its catalytic capabilities toward arachidonic and lauric acids (AA and LA). Specific and sensitive mass spectrometry assays enabled discrimination of the regioselectivity of hydroxylation of these two fatty acids. CYP4Z1 generated 7-, 8-, 9-, 10-, and 11-hydroxy LA, whereas the 12-hydroxy metabolite was not detected. HET0016, the prototypic CYP4 inhibitor, only weakly inhibited laurate metabolite formation (IC50 ∼15 μM). CYP4Z1 preferentially oxidized AA to the 14(S),15(R)-epoxide with high regioselectivity and stereoselectivity, a reaction that was also insensitive to HET0016, but neither 20-HETE nor 20-carboxy-AA were detectable metabolites. Docking of LA and AA into a CYP4Z1 homology model was consistent with this preference for internal fatty acid oxidation. Thus, human CYP4Z1 has an inhibitor profile and product regioselectivity distinct from most other CYP4 enzymes, consistent with CYP4Z1's lack of a covalently linked heme. These data suggest that, if CYP4Z1 modulates breast cancer progression, it does so by a mechanism other than direct production of 20-HETE. |
| Databáze: | OpenAIRE |
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