Cytochrome P450 BM3 (P450 102) from Bacillus megaterium is a unique bacterial P450, formed from the fusion of a fatty acid hydroxylase to a eukaryotic-like NADPH-cytochrome P450 reductase flavoprotein in a single (1 19 kDa) polypeptide chain (1, 2). It is an attractive model system for enzymological and structural studies due to its homology with mammalian drug metabolising P450 systems, and wi...

The results of a limited number of studies on echinoderms provide evidence for the presence of a cytochrome P450 monooxygenase system in representatives of three classes of the phylum Echinodermata: the asteroids (sea stars), holothuroids (sea cucumbers) and echinoids (sea urchins). The monooxygenase system has been demonstrated to be involved in the metabolism of xenobiotic compounds, but is a...

cyp3a4 probably has the broadest catalytic activity of any cytochrome p450. it is a crucial task to test new drug candidates in a reliable system for their ability to induce expression of this enzyme. firstly, a total of 300 bp core distal enhancer of cyp3a4 xrem region (-7972/-7673) were amplified from human genomic dna. the pcr product was then ligated into a human secretory alkaline phosphat...

The studies presented here were designed to elucidate the enzymes involved in the biotransformation of naturally occurring 1, 8-dihydroxyanthraquinones and to investigate whether biotransformation of 1,8-dihydroxyanthraquinones may represent a bioactivation pathway. We first studied the metabolism of emodin (1, 3,8-trihydroxy-6-methylanthraquinone), a compound present in pharmaceutical preparat...

A cytochrome P450 was purified from microsomes of Rhodotorula minuta. The optical spectrum of the purified cytochrome was characteristic of a low-spin ferric heme protein. Isovalerate caused a type I spectral change in it. The amino-terminal sequence of the cytochrome was different from those of other known microsomal cytochrome P450s. These results indicate that the cytochrome, which is tentat...

The alkylation of DNA, RNA and protein by labeled metabolites of [alpha-14C]nitrosodimethylamine (NDMA), [alpha-14C]nitrosodipropylamine (NDPA) and [alpha-14C]nitrosodibutylamine (NDBA) was determined as a measure of the metabolic activation of these nitrosamine carcinogens in vitro using microsomes prepared from freshly isolated rat hepatocytes as well as in intact cells using primary cultured...

Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after activation by cytochrome P450 (P450). Here, we investigated whether NADH:cytochrome b5 reductase (CBR) in the presence of cytochrome b5 can act as sole electron donor to human P450 1A1 during BaP oxidation and replace the canonical NADPH:cytochrome P450 reductase (POR) system. We also studied the efficiencies of the c...

Oleanolic acid (OA) is a pentacyclic triterpenoid widely found in plants and foods as an aglycone of saponins or free acid. OA exhibits beneficial activities for humans, including antitumor, antivirus, hepatoprotection properties without apparent toxicity. The metabolites produced by the cytochrome P450 (P450) enzymes are critical evaluation efficacy safety drugs. In this study, potential were ...