Catalytic Properties of the Plant Cytochrome P450 CYP73 Expressed in Yeast. Substrate Specificity of a Cinnamate Hydroxylase
| Autor: | Francis Durst, Claudia Mignotte-Vieux, Yannick Batard, Danièle Werck-Reichhart, Marie Agnès Pierrel, Michael Kazmaier |
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| Rok vydání: | 1994 |
| Předmět: |
Naringenin
Stereochemistry Trans-Cinnamate 4-Monooxygenase Saccharomyces cerevisiae Hydroxylation Umbelliferone Biochemistry Catalysis Mixed Function Oxygenases Substrate Specificity Xenobiotics chemistry.chemical_compound Cytochrome P-450 Enzyme System Herniarin Organic chemistry Binding Sites biology Substrate (chemistry) Cytochrome P450 Coumarin Recombinant Proteins Yeast Oxygen Kinetics chemistry biology.protein Helianthus |
| Zdroj: | European Journal of Biochemistry. 224:835-844 |
| ISSN: | 1432-1033 0014-2956 |
| DOI: | 10.1111/j.1432-1033.1994.00835.x |
| Popis: | The catalytic properties of CYP73, a cinnamate 4-hydroxylase isolated from Helianthus tuberosus tuber [Teutsch, H. G., Hasenfratz, M. P., Lesot, A., Stoltz, C., Garnier, J. M., Jeltsch, J. M., Durst, F. & Werck-Reichhart, D. (1993) Proc. Natl Acad. Sci. USA 90, 4102-4106] and expressed in an optimised yeast system [Urban, P., Werck-Reichart, D., Teutsch, G. H., Durst, F., Regnier, S., Kazmaier, M. & Pompon, D. (1994) Eur. J. Biochem. 222, 843-850] have been investigated. Microsomes from transformed yeast catalysed trans-cinnamate hydroxylation with high efficiency. CYP73 was highly specific for its natural substrate, and did not catalyse oxygenation of p-coumarate, benzoate, ferulate, naringenin or furanocoumarins. No metabolism of terpenoids or fatty acids, known substrates of plant P450s, was observed. CYP73 however demethylated the natural coumarin herniarin into umbelliferone. In addition, it was shown to oxygenate five xenobiotics and mechanism-based inactivators, including the herbicide chlorotoluron. All substrates of CYP73 were small planar aromatic molecules. Comparison of the kinetic parameters of CYP73 for its various substrates showed that, as expected, cinnamate was by far the best substrate of this P450. The physiological and toxicological significance of these observations are discussed. |
| Databáze: | OpenAIRE |
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