Common genetic variations of the cytochrome P450 1A1 gene and risk of hepatocellular carcinoma in a Chinese population

2009 ◽  
Vol 45 (7) ◽  
pp. 1239-1247 ◽  
Author(s):  
Rui Li ◽  
Yin Yao Shugart ◽  
Weiping Zhou ◽  
Yu An ◽  
Yuan Yang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cytochrome P450 ◽  
Chinese Population ◽  
Genetic Variations ◽  
Cytochrome P450 1A1

Molecular Regulation of Cytochrome P450 1A1 Induction By Hyperoxia in Human Pulmonary Cells

PEDIATRICS ◽  
2016 ◽  
Vol 137 (Supplement 3) ◽  
pp. 507A-507A
Author(s):  
Sudeepta K Basu ◽  
Renjithkumar Kalikkot Thekkeveedu ◽  
Chun Chu ◽  
Paramhamsa Maturu ◽  
Weiwu Jiang ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Molecular Regulation ◽  
Cytochrome P450 1A1 ◽  
Pulmonary Cells

The Molecular and Enzyme Kinetic Basis for Altered Activity of Three Cytochrome P450 2C19 Variants Found in the Chinese Population

2020 ◽  
Vol 13 (3) ◽  
pp. 233-244
Author(s):  
Amelia Nathania Dong ◽  
Nafees Ahemad ◽  
Yan Pan ◽  
Uma Devi Palanisamy ◽  
Beow Chin Yiap ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Molecular Docking ◽  
Active Site ◽  
Chinese Population ◽  
Accessible Surface Area ◽  
Solvent Accessible Surface Area ◽  
In Vitro Assays ◽  
Access Channel ◽  
Cytochrome P450 2C19

Background: There is a large inter-individual variation in cytochrome P450 2C19 (CYP2C19) activity. The variability can be caused by the genetic polymorphism of CYP2C19 gene. This study aimed to investigate the molecular and kinetics basis for activity changes in three alleles including CYP2C19*23, CYP2C19*24 and CYP2C19*25found in the Chinese population. Methods: The three variants expressed by bacteria were investigated using substrate (omeprazole and 3- cyano-7-ethoxycoumarin[CEC]) and inhibitor (ketoconazole, fluoxetine, sertraline and loratadine) probes in enzyme assays along with molecular docking. Results: All alleles exhibited very low enzyme activity and affinity towards omeprazole and CEC (6.1% or less in intrinsic clearance). The inhibition studies with the four inhibitors, however, suggested that mutations in different variants have a tendency to cause enhanced binding (reduced IC50 values). The enhanced binding could partially be explained by the lower polar solvent accessible surface area of the inhibitors relative to the substrates. Molecular docking indicated that G91R, R335Q and F448L, the unique mutations in the alleles, have caused slight alteration in the substrate access channel morphology and a more compact active site cavity hence affecting ligand access and binding. It is likely that these structural alterations in CYP2C19 proteins have caused ligand-specific alteration in catalytic and inhibitory specificities as observed in the in vitro assays. Conclusion: This study indicates that CYP2C19 variant selectivity for ligands was not solely governed by mutation-induced modifications in the active site architecture, but the intrinsic properties of the probe compounds also played a vital role.

Chicken Egg Yolk as an Excellent Source of Highly Specific Antibodies Against Cytochromes P450

2004 ◽  
Vol 69 (3) ◽  
pp. 659-673 ◽  
Author(s):  
Petr Hodek ◽  
Tomáš Koblas ◽  
Helena Rýdlová ◽  
Božena Kubíčková ◽  
Miroslav Šulc ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cytochromes P450 ◽  
Egg Yolk ◽  
Good Alternative ◽  
Invasive Technique ◽  
Cytochrome P450 1A1 ◽  
Orconectes Limosus ◽  
Chicken Egg ◽  
Cytochrome P450 2B4 ◽  
Human Livers

Using chicken antibodies IgY (purified from egg yolks) against mammalian cytochromes P450 and by means of cytochrome P450 marker substrates, we found for the first time the presence of hepatopancreatic cytochrome P450 in crayfishOrconectes limosus(an inducible cytochrome P450 2B-like enzyme) and we were able to detect and quantify cytochrome P450 1A1 in microsomes of human livers. Expression levels of cytochrome P450 1A1 in human livers constituted less than 0.6% of the total hepatic cytochrome P450 complement. The results obtained in our study are clear examples that chicken IgY are suitable for cytochrome P450 detection and quantification. Due to the evolutionary distance, chicken IgY reacts with more epitopes on a mammalian antigen, which gives an amplification of the signal. Moreover, this approach offers many advantages over common mammalian antibody production since chicken egg is an abundant source of antibodies (about 100 mg IgY/yolk) and the egg collection is a non-invasive technique. In the case of antibodies against cytochrome P450 2B4, we documented fast and steady production of highly specific immunoglobulins. Thus, chicken antibodies should be considered as a good alternative to and/or superior substitute for conventional polyclonal antibody produced in mammals.

scholarly journals An electron transfer competent structural ensemble of membrane-bound cytochrome P450 1A1 and cytochrome P450 oxidoreductase

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Goutam Mukherjee ◽  
Prajwal P. Nandekar ◽  
Rebecca C. Wade
Keyword(s):  
Electron Transfer ◽  
Cytochrome P450 ◽  
Drug Targets ◽  
Catalytic Domain ◽  
Cytochrome P450 1A1 ◽  
P450 Oxidoreductase ◽  
Distal Side ◽  
Cytochrome P450 Oxidoreductase ◽  
Membrane Bound ◽  
Transient Interactions

AbstractCytochrome P450 (CYP) heme monooxygenases require two electrons for their catalytic cycle. For mammalian microsomal CYPs, key enzymes for xenobiotic metabolism and steroidogenesis and important drug targets and biocatalysts, the electrons are transferred by NADPH-cytochrome P450 oxidoreductase (CPR). No structure of a mammalian CYP–CPR complex has been solved experimentally, hindering understanding of the determinants of electron transfer (ET), which is often rate-limiting for CYP reactions. Here, we investigated the interactions between membrane-bound CYP 1A1, an antitumor drug target, and CPR by a multiresolution computational approach. We find that upon binding to CPR, the CYP 1A1 catalytic domain becomes less embedded in the membrane and reorients, indicating that CPR may affect ligand passage to the CYP active site. Despite the constraints imposed by membrane binding, we identify several arrangements of CPR around CYP 1A1 that are compatible with ET. In the complexes, the interactions of the CPR FMN domain with the proximal side of CYP 1A1 are supplemented by more transient interactions of the CPR NADP domain with the distal side of CYP 1A1. Computed ET rates and pathways agree well with available experimental data and suggest why the CYP–CPR ET rates are low compared to those of soluble bacterial CYPs.

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