Difference between revisions of "Part:BBa K5477047"

Revision as of 20:09, 1 October 2024

Detoxification device against dioxin and PCBs

In this system, we have integrated two detoxification modules in yeast to create a device for the removal of environmental pollutants, including dioxins and polychlorinated biphenyls (PCBs). These modules, CYP1A1-pGAL1/10-POR and UDPD-pGAL1/10-UGT1A1, work in tandem under the control of the pGAL1/10 bidirectional promoter, which allows for the expression of the enzymes in opposite directions.

The CYP1A1-pGAL1/10-POR module addresses phase I metabolism. CYP1A1 catalyzes the oxidation of compounds like dioxin and PCBs, converting these toxic hydrophobic molecules into more reactive and soluble intermediates. This reaction requires electrons supplied by cytochrome P450 oxidoreductase (POR), which transfers electrons from NADPH to CYP1A1. This step transforms hydrophobic environmental pollutants into more hydrophilic compounds. The UDPD-pGAL1/10-UGT1A1 module complements this system by facilitating phase II metabolism. UGT1A1 (UDP-glucuronosyltransferase 1A1) conjugates glucuronic acid to the oxidized intermediates produced by CYP1A1, making them even more soluble and ready for excretion. However, for this reaction to proceed, a constant supply of UDP-glucuronic acid is needed, which is generated by UDP-glucose dehydrogenase (UDPD). UDPD converts UDP-glucose into UDP-glucuronic acid, providing UGT1A1 with the necessary substrate for the glucuronidation process. This modification significantly enhances the excretion of the pollutants via bile or urine, effectively detoxifying the yeast cells and reducing the toxicity of these compounds (1).

Together, these two modules, regulated by the bidirectional pGAL1/10 promoter, form an integrated detoxification system that mimics both phase I (oxidation) and phase II (conjugation) of human metabolism. By expressing these systems in yeast, we can efficiently detoxify environmental pollutants such as dioxins, and PCBs, transforming them into less toxic, more water-soluble metabolites that can be readily excreted. The following composites were used to build this device: BBa_K5477037 and BBa_K5477036

Sequence and Features

References

1. Inui H, Itoh T, Yamamoto K, Ikushiro S, Sakaki T. Mammalian cytochrome P450-dependent metabolism of polychlorinated dibenzo-p-dioxins and coplanar polychlorinated biphenyls. Int J Mol Sci. 2014 Aug 13;15(8):14044-57. doi: 10.3390/ijms150814044. PMID: 25123135; PMCID: PMC4159838.

CYP1A1 refs Grimm FA, Hu D, Kania-Korwel I, Lehmler HJ, Ludewig G, Hornbuckle KC, et al. Metabolism and metabolites of polychlorinated biphenyls. Crit Rev Toxicol. 2015 Mar;45(3):245–72.

Liu J, Tan Y, Song E, Song Y. A Critical Review of Polychlorinated Biphenyls Metabolism, Metabolites, and Their Correlation with Oxidative Stress. Chem Res Toxicol. 2020 Aug 17;33(8):2022–42.