A RECONSTITUTED CYTOCHROME P450 SYSTEM FROM TULIP BULBS (TULIPA FOSTERIANA L) OXIDIZES XENOBIOTICS

摘要

The microsomal fraction from tulip bulbs (Tulipa fosteriana L.) contains cytochrome P450 enzymes catalyzing the NADPH-dependent N-demethylation of the xenobiotics N-nitrosomethylaniline (NMA), N-nitrosodimethylamine (NDMA) and aminopyrine. A cytochrome P450 has been solubilized and purified from this tissue, Demethylation of the xenobiotics NMA, NDMA and aminopyrine has also been assessed in a reconstituted electron-transport chain with the isolated cytochrome P450, phospholipid and isolated plant NADPH-cytochrome P450 reductase. A molar ratio of 0.65 of cytochrome P450 to the reductase is the most appropriate for the catalysis, Besides N-demethylation of NMA, denitrosation of this substrate is catalyzed by the plant cytochrome P450-dependent reconstituted system, The results demonstrate the progress in reconstitution techniques allowing the recovery of the activity of plant cytochrome P450s oxidizing xenobiotics. [References: 44]