Characterization of an interesting selenium-dependent glutathione peroxidase (Se-GPx) protecting cells against environmental stress: The Camelus dromedarius erythrocytes Se-GPx
| Autor: | Abdelkhalid Essamadi, Abdelbasset Chafik, Kübra Solak, Ahmet Mavi, Safinur Yildirim Çelik |
|---|---|
| Přispěvatelé: | Bayburt University |
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Camel Chemistry Glutathione peroxidase Ion chromatography chemistry.chemical_element Bioengineering Environmental stress Glutathione medicine.disease_cause Applied Microbiology and Biotechnology chemistry.chemical_compound Enzyme Biochemistry Acetone medicine Desert Hydrogen peroxide Biochemical properties Agronomy and Crop Science Selenium Oxidative stress Food Science Biotechnology |
| Zdroj: | Biocatalysis and Agricultural Biotechnology. 18:101000 |
| ISSN: | 1878-8181 |
| DOI: | 10.1016/j.bcab.2019.01.038 |
| Popis: | Camel lives most of its life under high environmental stress in the desert. Glutathione peroxidase plays a key role in protecting cells against oxidative stress. For the first time, selenium-dependent glutathione peroxidase (Se-GPx) was purified from camel erythrocytes, biochemically characterized, and some of its properties were studied. The enzyme was purified using ethanol-chloroform treatment, acetone precipitation and ion exchange chromatography. A purification fold of 33.72 with 0.19% yield were obtained. The native molecular weight of the enzyme was estimated to be about 69 kDa. On SDS-PAGE, the enzyme was composed of two different subunits with a molecular weight of approximately 53 and 21 kDa. An optimum temperature of 47 °C and an optimum pH of 7.2 were found. The activation energy was 41.71 kJ/mol. This enzyme was inhibited by thiol reagents, D,L-Dithiothreitol and ?-Mercaptoethanol, and was sensitive to bivalent cations. The enzyme had a general specificity toward hydroperoxides, and high specificity for reduced glutathione. The purified enzyme contained 3.06 mol of selenium per mol of protein. The Km and Vmax values for hydrogen peroxide and reduced glutathione were 0.72 and 1.58 mM, and 25.33 and 31.03 U/mg, respectively. The biochemical properties of camel Se-GPx were different comparing to those of mammalian species. Lower molecular weight, heterodimeric structure, higher optimum temperature, relatively lower optimum pH, lower content of selenium and higher affinity for hydrogen peroxide at low reduced glutathione concentration, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert. © 2019 Elsevier Ltd |
| Databáze: | OpenAIRE |
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