کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10804579 | 1057292 | 2005 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular characterization of a glutathione transferase from Pinus tabulaeformis (Pinaceae)
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کلمات کلیدی
ECAGSHGSTCDNB4-NPA1-chloro-2,4-dinitrobenzene - 1-کلرو-2،4-دینیتروبنزن7-chloro-4-nitrobenzo-2-oxa-1,3-diazole - 7-کلرو-4-نیتربنزو-2-اکسا-1،3-دیازولSite-directed mutagenesis - mutagenesis مواجه با سایتNBD-Cl - NBD-CLEthacrynic acid - اسید اتاکریونیکCloning - تاگسازی یا شبیه سازیProtein structure - ساختار پروتئینEnzyme activity - فعالیت آنزیمGymnosperm - کوهنوردیGlutathione - گلوتاتیونGlutathione transferase - گلوتاتیون ترانسفراز
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Glutathione transferases (GSTs) play important roles in stress tolerance and detoxification metabolism in plants. To date, studies on GSTs in higher plants have focused largely on agricultural plants. In contrast, there is virtually no information on the molecular characteristics of GSTs in gymnosperms. The present study reports for the first time the cloning, expression and characteristics of a GST gene (PtGSTU1) from a pine, Pinus tabulaeformis, which is widely distributed from northern to central China covering cold temperate and drought regions. The PtGSTU1 gene encodes a protein of 228 amino acid residues with a calculated molecular mass of 26.37 kDa. Reverse transcription PCR revealed that PtGSTU1 was expressed in different tissues, both above and below ground, of P. tabulaeformis. The over-expressed recombinant PtGSTU1 showed high activity towards the substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl). Kinetic analysis with respect to CDNB as substrate revealed a Km of 0.47 mM and Vmax of 169.1 μmol/min per mg of protein. The recombinant PtGSTU1 retained more than 60% of its maximum enzymatic activity from 15°C to 45°C with a broad optimum Tm range of 25°C - 35°C. The enzyme had a maximum activity at approximately pH 8.5 - 9.0. Site-directed mutagenesis revealed that Ser13 in the N-terminal domain is a critical catalytic residue, responsible for stabilisation of the thiolate anion of enzyme-bound glutathione. Based on comparative analyses of its amino acid sequence, phylogeny and predicted three-dimensional structure, the PtGSTU1 should be classified as a tau class GST.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimie - Volume 87, Issue 5, May 2005, Pages 445-455
Journal: Biochimie - Volume 87, Issue 5, May 2005, Pages 445-455
نویسندگان
Qing-Yin Zeng, Hai Lu, Xiao-Ru Wang,