کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1984647 1539960 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A novel selenium-containing glutathione transferase zeta1-1, the activity of which surpasses the level of some native glutathione peroxidases
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
A novel selenium-containing glutathione transferase zeta1-1, the activity of which surpasses the level of some native glutathione peroxidases
چکیده انگلیسی
Glutathione peroxidase (GPX) is a critical antioxidant selenoenzyme in organisms that protects cells against oxidative damage by catalyzing the reduction of hydroperoxides by glutathione (GSH). Thus, some GPX mimics have been generated because of their potential therapeutic value. The generation of a semisynthetic selenoenzyme with peroxidase activity, which matches the catalytic efficiencies of naturally evolved GPX, has been a great challenge. Previously, we semisynthesized a GPX mimetic with high catalytic efficiency using a rat theta class glutathione transferase (rGST T2-2) as a scaffold, in which the highly specific GSH-binding site is adjacent to an active site serine residue that can be chemically modified to selenocysteine (Sec). In this study, we have taken advantage of a new scaffold, hGSTZ1-1, in which there are two serine residues in the active site, to achieve both high thiol selectivity and highly catalytic efficiency. The GPX activity of Se-hGSTZ1-1 is about 1.5 times that of rabbit liver GPX, indicating that the selenium content at the active site plays an important role in enhancement of catalytic performance. Kinetic studies revealed that the catalytic mechanism of Se-hGSTZ1-1 belong in a ping-pong mechanism similar to that of the natural GPX.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The International Journal of Biochemistry & Cell Biology - Volume 40, Issue 10, 2008, Pages 2090-2097
نویسندگان
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