Different Oxidation Pathways of 2-Selenouracil and 2-Thiouracil, Natural Components of Transfer RNA
| Autor: | Barbara Nawrot, Barbara Pacholczyk-Sienicka, Katarzyna Kulik, Ewelina Wielgus, Klaudia Sadowska, Elzbieta Sochacka |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Stereochemistry chemistry.chemical_element 01 natural sciences Peroxide Article Catalysis Thiouracil Inorganic Chemistry Diselenide lcsh:Chemistry 03 medical and health sciences Chalcogen chemistry.chemical_compound 2-thiouracil oxidative stress Physical and Theoretical Chemistry Hydrogen peroxide Uracil Molecular Biology tRNA modified nucleoside lcsh:QH301-705.5 Spectroscopy 010405 organic chemistry Organic Chemistry 2-selenouridine General Medicine Hydrogen Peroxide 2-selenouracil Sulfur 0104 chemical sciences Computer Science Applications 030104 developmental biology chemistry lcsh:Biology (General) lcsh:QD1-999 2-thiouridine Oxidation-Reduction Selenium |
| Zdroj: | International Journal of Molecular Sciences, Vol 21, Iss 5956, p 5956 (2020) International Journal of Molecular Sciences Volume 21 Issue 17 |
| ISSN: | 1661-6596 1422-0067 |
| Popis: | Sulfur- and selenium-modified uridines present in the wobble position of transfer RNAs (tRNAs) play an important role in the precise reading of genetic information and tuning of protein biosynthesis in all three domains of life. Both sulfur and selenium chalcogens functionally operate as key elements of biological molecules involved in the protection of cells against oxidative damage. In this work, 2-thiouracil (S2Ura) and 2-selenouracil (Se2Ura) were treated with hydrogen peroxide at 1:0.5, 1:1, and 1:10 molar ratios and at selected pH values ranging from 5 to 8. It was found that Se2Ura was more prone to oxidation than its sulfur analog, and if reacted with H2O2 at a 1:1 or lower molar ratio, it predominantly produced diselenide Ura-Se-Se-Ura, which spontaneously transformed to a previously unknown Se-containing two-ring compound. Its deselenation furnished the major reaction product, a structure not related to any known biological species. Under the same conditions, only a small amount of S2Ura was oxidized to form Ura-SO2H and uracil (Ura). In contrast, 10-fold excess hydrogen peroxide converted Se2Ura and S2Ura into corresponding Ura-SeOnH and Ura-SOnH intermediates, which decomposed with the release of selenium and sulfur oxide(s) to yield Ura as either a predominant or exclusive product, respectively. Our results confirmed significantly different oxidation pathways of 2-selenouracil and 2-thiouracil. |
| Databáze: | OpenAIRE |
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