Oxidative metabolic profiling of xenobiotics by human P450s expressed in tobacco cell suspension cultures.
Elucidation of metabolic pathways of xenobiotics (pesticides, pharmaceuticals and industrial pollutants) in human, animals and plants and chemical identification of corresponding metabolites are required for comprehensive (eco-) toxicological evaluation of the compounds prior to their usage. The most important metabolic products are oxidized metabolites, and most of these are formed by catalytic activity of P450s (cytochrome P450 mono-oxygenases). In human, 11 P450 isoenzymes exhibiting broad and overlapping substrate specificities are responsible for approx. 90% of drug metabolism. As support for inevitable metabolism studies with intact organisms under relevant conditions, tobacco cell cultures were transformed separately with cDNA sequences of human P450 isoenzymes CYP1A1, CYP1A2 and CYP3A4. The resulting P450-transgenic cell suspensions were used for metabolism studies with pesticides, industrial pollutants, a secondary plant metabolite and human sex hormones. A summary of basic results is provided; these are discussed regarding application of the method for screening of the oxidative metabolism of xenobiotics and the large-scale production of metabolites.
Schmidt
B
B
Institute of Biology V, RWTH Aachen University, Worringerweg 1, 52056 Aachen, Germany. burkhard.schmidt@post.rwth-aachen.de
Joussen
N
N
Bode
M
M
Schuphan
I
I
D000818:Animals; D001711:Biotransformation; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008322:Mammals; D010944:Plants / Q000201:enzymology; D030821:Plants, Genetically Modified / Q000201:enzymology; D011994:Recombinant Proteins / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000201:enzymology; D015262:Xenobiotics / Q000378:metabolism*
D011994:Recombinant Proteins; D015262:Xenobiotics; D003577:Cytochrome P-450 Enzyme System; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human