We previously described the development of genetic models to study the in vivo functions of the hepatic cytochrome P450 (P450) system, through the hepatic deletion of either cytochrome P450 oxidoreductase [POR; HRN (hepatic reductase null) line] or cytochrome b5 [HBN (hepatic cytochrome b5 null) line]. However, HRN mice still exhibit low levels of mono-oxygenase activity in spite of the absence...

A three-dimensional structural model of rabbit phenobarbital-inducible cytochrome P450 2B4 (LM2) was constructed by homology modeling techniques previously developed for building and evaluating a 3D model of the cytochrome P450choP isozyme. Four templates with known crystal structures including cytochrome P450cam, terp, BM-3 and eryF were used in multiple sequence alignments and construction of...

CandidatusLiberibacter asiaticus (Las) has been reported to increase the susceptibility of theAsian citrus psyllid,Diaphorina citriKuwayama (Hemiptera: Psyllidae), to selected insecticides. Reduced general esterase activity in Las-infected, compared with uninfected, D. citri has been proposed as a possible explanation for this difference in insecticide susceptibility. The current study was cond...

Cytochrome P450, a family of monooxygenase enzymes, is organized as a catalytic metabolon, which requires enzymatic partners as well as environmental factors that tune its complex dynamic. P450 and its reducing counterparts-cytochrome P450-reductase and cytochrome b 5 -are membrane-bound proteins located in the cytosolic side of the endoplasmic reticulum. They are believed to dynamically associ...

Several heterocyclic amines, found in cooked food, are powerful mutagens in the Ames Salmonella mutagenicity test system. One of these, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) is one of the most mutagenic chemicals tested in this assay. In primary cultures of chick and rat hepatocytes, MeIQ, by itself, induced cytochrome P450 from the IA subfamily but was a weak inducer compared to 3...

Quinones are widely distributed in nature, and some quinone compounds are used as therapeutic agents such as anti-cancer, anti-malarial or anti-bacterial drugs. However, their therapeutic use is limited in some cases because the use of most quinones is accompanied by adverse effects derived from their cytotoxicity, especially for hepatocytes. Two mechanisms have been proposed to explain quinone...

Microbial transformation is an essential component for the commercial production of numerous valuable steroid drugs such as hydrocortisone, prednisolone. Steroid hydroxylation at C11 and C15 positions by filamentous fungi is routinely employed in the steroid industry due to both the necessity of regioand stereoselective oxyfunctionalization of unactivated C-H bonds of valuable steroid compounds...

Ethylene (74-85-1) is an important petrochemical and is produced endogenously. It is metabolized to ethylene oxide (EO) by cytochrome P450. We studied the inhibition of cytochrome P450 activity during exposure to ethylene, and verified that this inhibition was reflected in the concentration of EO in the blood. Male F344 rats were exposed to 1000, 600, and 300 ppm ethylene by nose-only inhalatio...