scholarly journals Development of Saccharomyces cerevisiae Y486–based biosensor carrying both CPR-CYP3A4 and DIN7-GFP constructs for mutagenicity testing of procarcinogens

2021 ◽  
Vol 19 (1) ◽  
pp. 185-196
Author(s):  
Nguyen Thi Thu Huyen ◽  
Bui Van Ngoc
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Healthcare Services ◽  
Toxic Substances ◽  
Cytochrome P450 Enzymes ◽  
Inducible Promoters ◽  
Human Cytochrome ◽  
Specific Substance ◽  
Promoter Gene ◽  
Cyp3a4 Enzyme ◽  
Further Development

In the world and Vietnam, a great number of toxic substances from industrial and agricultural activities, food production, and healthcare services are daily released into the environment. Many exogenous harmful substances are procarcinogens, but become carcinogens by the bioactivation of human cytochrome P450 enzymes (CYPs). Thus, development of analytical testing for rapid detection of procarcinogens plays a crucial role in food safety and environmental monitoring. This study aims to establish a biosensor basing on Saccharomyces cerevisiae Y486 cotransformed with two promoter–gene constructs, CYP3A4–CPR and DIN7–GFP. The results showed that all recombinant proteins were coexpressed in Y486 cells. The molecular weight of recombinant CPR and CYP3A4 were 75 kDa and 56 kDa, respectively. CYP3A4 enzyme only showed its catalytic activity in biotransformation of the specific substance as coexpressed with CPR. Kinetic constants, Km, Vmax, and Vmax/Km, of this CPR–CYP3A4 enzyme complex were 3.2 µM, 3.5 pmol/pmol CYP/min, and 1.1 μL/pmol CYP/min, respectively. Coexpressing constructs of CPR–CYP3A4 and DIN7-GFP in Y486 strain was able to identify aflatoxin B1 in the range of 0.1 - 0.4 µM; benzo(c)pyrene in the range of 10 - 40 µM. However, this system could not detect other procacinogens, such as, N-Nitrosodimethylamine, at any investigated concentrations. These findings were the first trial for further development of other biosensors to determine diverse procarcinogens in the enviroment by redesign of coexpressing constructs or replacement of the specific CYPs and inducible promoters.

In vitro inhibitory mechanisms and molecular docking of 1′-S-1′-acetoxychavicol acetate on human cytochrome P450 enzymes

Phytomedicine ◽  
2017 ◽  
Vol 31 ◽  
pp. 1-9 ◽  
Author(s):  
A.K.M. Mahmudul Haque ◽  
Kok Hoong Leong ◽  
Yoke Lin Lo ◽  
Khalijah Awang ◽  
Noor Hasima Nagoor
Keyword(s):  
Cytochrome P450 ◽  
Molecular Docking ◽  
Cytochrome P450 Enzymes ◽  
Inhibitory Mechanisms ◽  
Human Cytochrome

Characterization of Diuron N-Demethylation by Mammalian Hepatic Microsomes and cDNA-Expressed Human Cytochrome P450 Enzymes

2007 ◽  
Vol 35 (9) ◽  
pp. 1634-1641 ◽  
Author(s):  
Khaled Abass ◽  
Petri Reponen ◽  
Miia Turpeinen ◽  
Jorma Jalonen ◽  
Olavi Pelkonen
Keyword(s):  
Cytochrome P450 ◽  
Cytochrome P450 Enzymes ◽  
Hepatic Microsomes ◽  
Human Cytochrome

scholarly journals Pathways of Carbamazepine Bioactivation in Vitro. III. The Role of Human Cytochrome P450 Enzymes in the Formation of 2,3-Dihydroxycarbamazepine

2008 ◽  
Vol 36 (8) ◽  
pp. 1637-1649 ◽  
Author(s):  
Robin E. Pearce ◽  
Wei Lu ◽  
YongQiang Wang ◽  
Jack P. Uetrecht ◽  
Maria Almira Correia ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cytochrome P450 Enzymes ◽  
Human Cytochrome

scholarly journals A Historical Review of the Benefits and Hypothetical Risks of Disinfecting Drinking Water by Chlorination

2017 ◽  
Vol 8 (1) ◽  
pp. 73 ◽  
Author(s):  
Philip C.W. Cheung
Keyword(s):  
Drinking Water ◽  
Public Discourse ◽  
Inorganic Compounds ◽  
Historical Review ◽  
World Health ◽  
Free Radical Scavengers ◽  
Special Interest Groups ◽  
Toxic Substances ◽  
Cytochrome P450 Enzymes ◽  
The Public

This review examines the benefits and alleged risks associated with the disinfection of drinking water by chlorination, through critical appraisal of the historical saga of chloroform as the main disinfection by-product (DBP). The author maintains that the provision of clean drinking water is a survival issue for humankind and supports unreservedly the recommendation by the World Health Organization (WHO) of the United Nations to disinfect by chlorination, for the reasons stated herein. The author aims to lead water professionals to a deeper understanding of the public health issues concerning chloroform and how the corpus of knowledge was attained by colossal multi-disciplinary effort on a global scale.Origins of the alleged risks of chlorination are traced and the assumptions behind these allegations are questioned. The author welcomes and encourages innovations for improved methods of water treatment insofar that the standards of potability set out by the WHO are met in the very least, but argues that the commencement point of research into new techniques should be an acknowledgment of the development of disinfection up to contemporary times, on the part of water engineers and policy makers. There must be a clear recognition of the horrific consequences of failure to eliminate pathogens and toxic substances. To this effect, landmark tragedies are described to emphasize the point.Significantly, this work addresses topics which are sine quo non to the debate over chlorination but which are often lacking in public discourse, namely: differences in the way cytochrome P450 enzymes oxidize carbon tetrachloride which is not normally a product of chlorination, and chloroform, which is a disinfection by-product; the role of free radical scavengers in protecting the human body; the difficulties of extrapolating experimental results from rodents to humans; the awareness of the complex relationship between governments, chemical industries, special interest groups and the public. Also introduced are the aetiologies of some cancers (e.g., Hepatitis B and C viruses as the instigators for hepatocellular carcinoma) to juxtapose claims that chloroform in drinking water is the sole culprit responsible for liver, bladder, colorectal cancers and birth defects etc. Other well known human carcinogens and a few inorganic compounds known to cause harm are also depicted. Lastly, a structured approach towards integrating the overarching concepts in the analysis of alleged carcinogenicity is applied to chloroform and the inferences discussed.The literature reviewed spanned the years 1848 – 2017.

Sign in / Sign up

Export Citation Format

Share Document