Equine cytochrome P450 2C92: cDNA cloning, expression and initial characterization
Autor: | H. K. DiMAIO Knych, C. E Destefano Shields, Alan R. Buckpitt, Scott D Stanley |
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Rok vydání: | 2009 |
Předmět: |
DNA
Complementary Diclofenac Molecular Sequence Data Biophysics Gene Expression Spodoptera Biology Reductase Molecular cloning Biochemistry Substrate Specificity Cytochrome P-450 Enzyme System Species Specificity Complementary DNA Animals Humans Horses Cloning Molecular Molecular Biology Cytochrome b Cytochrome P450 Monooxygenase Molecular biology Enzyme assay Kinetics Liver Biocatalysis biology.protein Drug metabolism |
Zdroj: | Archives of Biochemistry and Biophysics. 485:49-55 |
ISSN: | 0003-9861 |
Popis: | Substantial gaps exist in our knowledge of the metabolic clearance of therapeutic agents in horses. Accordingly, a cytochrome P450 monooxygenase in the 2C family was cloned from an equine liver, sequenced and expressed in a baculovirus expression system. Catalytic activities of the recombinant protein were measured with a number of substrates. The protein, assigned CYP2C92, displayed optimal catalytic activity with diclofenac using molar ratios of CYP2C92 to NADPH CYP450 reductase of 1:18. Addition of cytochrome b(5) to diclofenac incubations had no significant effect on metabolic turnover. CYP2C92 catalyzed diclofenac metabolism was 20-fold slower than the human counterpart, CYP2C9. CYP2C92 demonstrated comparable tolbutamide and (S)-warfarin hydroxylase activity compared to CYP2C9, upon addition of b(5) to the reactions. The results of this study demonstrate substantial interspecies differences in metabolism of substrates by CYP2C orthologues in the horse and human and support the need to fully characterize this enzyme system in equids. |
Databáze: | OpenAIRE |
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