The metabolism of polychlorinated dibenzo-p-dioxins by cytochrome P450 BM-3 from Bacillus megaterium and a mutant enzyme of it (AL4V; Ala74Gly, Phe87Val, Leu188Gln triple mutant) was examined. Both purified enzymes metabolized 1-monochloro-, 2,3-dichloro-, and 2,3,7-trichloro-dibenzo-p-dioxin, but not 2,3,7,8-tetrachloro-dibenzo-p-dioxin. The mutant AL4V had 2-12 times higher activity than the wild-type P450 BM-3 towards polychlorinated dibenzo-p-dioxins. The products were hydroxylated at an unsubstituted position and/or showing migration of the chloride and were less toxic derivatives with lower than 10% toxicity of the original compounds.
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http://dx.doi.org/10.1007/s10529-004-5317-y | DOI Listing |
J Mol Histol
December 2024
Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, No.51, Weiliu Road, Jinan, Shandong Province, 250021, China.
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an important environmental pollutant that disturbs the immune balance of the maternal-fetal interface (MFI) and is also a common environmental factor for the formation of cleft palate (CP). Therefore, the purpose is to investigate whether TCDD can cause CP by disrupting the immune balance of the maternal-fetal interface. Fifteen C57BL/6J mice were randomly assigned to three groups: control group, TCDD group, and TCDD plus Freund's complete adjuvant (FCA) (TCDD + FCA) group.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Liquid crystal monomers (LCMs) are potentially persistent, bioaccumulative, and toxic emerging pollutants. However, their occurrence in outdoor PM and related human exposure risks remain unknown. In this study, 32 composite samples were analyzed, which were prepared from daily PM samples collected throughout the year 2021 -2022 in Beijing, China.
View Article and Find Full Text PDFFront Immunol
December 2024
Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States.
Exposure to environmental contaminants can result in profound effects on the host immune system. One class of environmental toxicants, known as dioxins, are persistent environmental contaminants termed "forever chemicals". The archetype toxicant from this group of chemicals is 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), an immunotoxicant that activates the aryl-hydrocarbon receptor pathway leading to a variety of changes in immune cell responses.
View Article and Find Full Text PDFChemosphere
December 2024
College of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, China.
Polychlorinated dibenzo-p-dioxins (PCDDs) are persistent organic pollutants that pose considerable threats to ecological and human health owing to their high toxicity potential. Understanding the mechanisms for underlying the base-catalyzed hydrolysis of PCDDs in aquatic environments is essential for assessing their environmental behaviour and ecological risks. Herein, we combined quantitative structure-activity relationship (QSAR) models with density functional theory calculations to analyse the base-catalyzed hydrolysis mechanisms of PCDDs.
View Article and Find Full Text PDFSci Total Environ
December 2024
Department of Environmental Science, Rutgers, the State University of New Jersey, United States of America. Electronic address:
Polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) are contaminants of concern in the New York/New Jersey Harbor and in the organisms of the Newtown Creek Superfund site, which lies within the harbor. Because PCDD/Fs are never intentionally produced, identifying their sources can be challenging. In this work, sources of PCDD/Fs to the sediment of Newtown Creek were investigated using Positive Matrix Factorization (PMF) to analyze two data sets containing data on concentrations of (1) PCDD/Fs and (2) PCDD/Fs plus polychlorinated biphenyls (PCBs).
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