|Characterization of the Cytochrome P450 CYP234: Expression in Rat Small Intestine and Role in Retinoic Acid Biotransformation from Retinal
||The sites of expression in the small intestine and the function of CYP2J4, a recently identified rat cytochrome (P450) isoform found to be predominantly expressed in the small intestine, were characterized. Immunoblot analysis with a polyclonal antib...
|Cytochrome P450 expression and activities in human tongue cells and their modulation by green tea extract
||The expression, inducibility, and activities of several cytochrome P450 (CYP) enzymes were investigated in a human tongue carcinoma cell model, CAL 27, and compared with the human liver model HepG2 cells. The modulation effects of green tea on variou...
|Cytochrome P450 expression and activities in rat, rabbit and bovine tongue
||Xenobiotic metabolism in the tongue has received little attention in the literature. In the present study, we report a comparative analysis of constitutive cytochrome P450 (CYP) expression and activities in the tongue. First we compared catalytic act...
|Defluorination of 4-fluorophenol by Cytochrome P450BM3-F87G: Activation by long Chain Fatty Aldehydes.
||Cytochrome P450BM3-F87G catalyzed the oxidative defluorination of 4-fluorophenol, followed by reduction of the resulting benzoquinone to hydroquinone via the NADPH P450-reductase activity of the enzyme. The k catand K m for this reaction were 71 ± 5 ...
|Effects of green tea extracts on gene expression in HepG2 and Cal-27 cells
||Green tea extract is known to contain compounds that are able to produce antioxidant effects in many types of living cells. Treatment of cultured human hepatoma (HepG2) cells with green tea extract resulted in dramatically increased expression of at ...
|Effects of herbal products and their constituents on human cytochrome P4502E1 activity
||Ethanolic extracts from fresh Echinacea purpurea and Spilanthes acmella and dried Hydrastis canadensis were examined with regard to their ability to inhibit cytochrome P4502E1 mediated oxidation of p-nitrophenol in vitro. In addition, individual cons...
|Farnesol as an inhibitor and substrate for rabbit liver microsomal P450 enzymes
||Farnesol and the related isoprenoids, geranylgeraniol, geranylgeranyl pyrophosphate, and farnesyl pyrophosphate, are produced in the endoplasmic reticulum of hepatocytes in mammals, and each serve important biological functions. Of these compounds, o...
|Isotopic labeling of the heme cofactor in cytochrome p450 and other heme proteins.
||A recombinant bacterial expression system that generates 13C-labeled heme or 15N-labeled heme in functional cytochrome P450 enzymes and other heme-containing systems is reported here using a mutant strain of Escherichia coli (HU227) in which the HemA...
|Liver Enzyme-Mediated Oxidation of Echinacea purpurea Alkylamides: Production of Novel Metabolites and Changes in Immunomodulatory Activity
||The medicinal plant Echinacea is widely used to treat upper respiratory infections and is reported to stimulate the human immune system. A major constituent class of Echinacea, the alkyl-amides, has immunomodulatory effects. Recent studies show that ...
|Membrane Topology of Cytochrome P450 2B4 in Langmuir-Blodgett Monolayers
||Using Langmuir–Blodgett monolayers of both phosphatidylethanolamines and phosphatidylcholines as membrane mimics, we have examined the topology of cytochrome P450 2B4 anchoring. The interaction of wild-type P450 2B4 with phosphatidylethanolamine mono...
|Oxymyohemerythrin: discriminating between O2 release and autoxidation
||Myohemerythrin (Mhr) is a non-heme iron O2 carrier (with two irons in the active site) that is typically found in the retractor muscle of marine ‘peanut’ worms. OxyMhr may either release O2, or undergo an autoxidation reaction i...
|Peroxo-iron and Oxenoid-iron Species as Alternative Oxygenating Agents in Cytochrome P450-catalyzed Reactions: Switching by Threonine-302 to Alanine Mutagenesis of Cytochrome P450 2B4.
||ABSTRACT Among biological catalysts, cytochrome
P450 is unmatchedi n its multiplicityo f isoforms,i nducers,
substrates,a nd typeso f chemical reactionsc atalyzed.I n the
presents tudy,e videncei s givent hatt hisv ersatilityex tendst o
|PksS from Bacillus subtilis is a cytochrome P450 involved in bacillaene metabolism
||As part of the pksX gene cluster of Bacillus subtilis strain 168, pksX has been preliminarily annotated as a cytochrome P450 homolog that hydroxylates the polyketide product of this cluster, which was recently shown to be involved in th...
|Single turnover studies of oxidative halophenol dehalogenation by horseradish peroxidase reveal a mechanism involving two consecutive one electron steps: toward a functional halophenol bioremediation catalyst.
||Horseradish peroxidase (HRP) catalyzes the oxidative para-dechlorination of the environmental pollutant/carcinogen 2,4,6-trichlorophenol (2,4,6-TCP). A possible mechanism for this reaction is a direct oxygen atom transfer from HRP compound I (HRP I) ...
|Spectroscopic investigations of intermediates in the reaction of cytochrome P450BM3–F87G with surrogate oxygen atom donors
||Rapid mixing of substrate-free ferric cytochrome P450BM3–F87G with m-chloroperoxybenzoic acid (mCPBA) resulted in the sequential formation of two high-valent intermediates. The first was spectrally similar to compound I species reported previously fo...
|Stopped-flow spectrophotometric analysis of intermediates in the peroxo-dependent inactivation of cytochrome P450 by aldehydes
||The reaction of hydrogen peroxide and certain aromatic aldehydes with cytochrome P450BM3-F87G results in the covalent modification of the heme cofactor of this monooxygenase. Analysis of the resulting heme by electronic absorption spectrop...
|Subzero-temperature stabilization and spectroscopic characterization of homogeneous oxyferrous complexes of the cytochrome P450 BM3 (CYP102) oxygenase domain and holoenzyme
||We describe herein for the first time the formation and spectroscopic characterization of homogeneous oxyferrous complexes of the cytochrome P450 BM3 (CYP102) holoenzyme and heme domain (BMP) at —55 °C using a 70/30 (v/v) glycerol/buffer cryosolvent....