کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2016554 | 1541974 | 2009 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Biochemical and physiological characterization of a tau class glutathione transferase from rice (Oryza sativa)
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
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چکیده انگلیسی
The classical phase II detoxification glutathione transferases (GSTs) are key metabolic enzymes that catalyze the conjugation of glutathione to various electrophilic compounds. A tau class GST gene (OsGSTU17) was cloned from rice, which encodes a protein of 223 amino acid residues with a calculated molecular mass of 25.18 kDa. The recombinant OsGSTU17 formed a homodimer protein and showed GSH-conjugating activity with various xenobiotics. Kinetic analysis with respect to NBD-Cl as substrate revealed a Km of 0.324 mM and Vmax of 0.219 μmol/min per mg of protein. The enzyme had a maximum activity at pH 7.5, and a high thermal stability with 81% of its initial activity at 55 °C for 15 min. Site-directed mutagenesis revealed that Ser15 in the N-terminal domain is a critical catalytic residue, responsible for stabilisation of the thiolate anion of enzyme-bound glutathione. OsGSTU17 mRNA was expressed in different tissues of rice, both above and below ground. The relative transcript levels of OsGSTU17 mRNA varied significantly among the tissues in response to CDNB, hydrogen peroxide and atrazine treatments, indicating the gene has diverse regulation mechanisms in response to abiotic stresses.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Plant Physiology and Biochemistry - Volume 47, Issues 11â12, NovemberâDecember 2009, Pages 1061-1068
Journal: Plant Physiology and Biochemistry - Volume 47, Issues 11â12, NovemberâDecember 2009, Pages 1061-1068
نویسندگان
Xue Yang, Wu Sun, Jiang-Peng Liu, Yan-Jing Liu, Qing-Yin Zeng,