Abstract
The development and validation of an online cytochrome P450 (CYP)-based bioreactor coupled to automated solid-phase extraction (SPE) and gradient HPLC separation is described. The analytical method was checked on intra- and inter-day repeatability of the ethoxyresorufin-O-demethylation (EROD) reaction with CYP 1Al/1A2 containing beta-NF induced rat liver microsomes as an enzyme source. These experiments showed that CYP activity was linearly decreased with 16% over an 11 h period. Inter-day measurements had a CV of 9.1%. Furthermore, Km and Vmax values of the EROD reaction, measured with the bioreactor, were 2.72 +/- 0.46 microM and 7.9 +/- 0.5 nmol/min/mg protein, respectively. These were in good correspondence with Km and Vmax values, measured with standard batch assay, which amounted 0.66 +/- 0.08 microM and 6.4 +/- 0.2 nmol/min/mg protein respectively. In conclusion the newly developed analytical method can be used effectively and at a microliter scale for online generation, extraction and separation of metabolites.
Original language | English |
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Pages (from-to) | 205-212 |
Number of pages | 8 |
Journal | Journal of Chromatography A |
Volume | 1075 |
Issue number | 1-2 |
Early online date | 20 Apr 2005 |
DOIs | |
Publication status | Published - 20 May 2005 |
Keywords
- Animals
- Cytochrome P-450 CYP1A1
- Kinetics
- Microsomes, Liver
- Rats
- Reproducibility of Results
- Journal Article
- Validation Studies