کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1977026 1060720 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Purification and properties of a glutathione peroxidase from Southern bluefin tuna (Thunnus maccoyii) liver
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Purification and properties of a glutathione peroxidase from Southern bluefin tuna (Thunnus maccoyii) liver
چکیده انگلیسی
A glutathione peroxidase (GPX) protein was purified approximately 1000-fold from Southern bluefin tuna (Thunnus maccoyii) liver to a final specific activity of 256 μmol NADPH oxidised min− 1 mg− 1 protein. Gel filtration chromatography and denaturing protein gel electrophoresis of the purified preparation indicated that the protein has a native molecular mass of 85 kDa and is most likely a homotetramer with subunits of approximately 24 kDa. The Km values of the purified enzyme for hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide and glutathione were 12, 90, 90 and 5900 μM, respectively. The Km values for cumene hydroperoxide and t-butyl hydroperoxide were approximately 8-fold greater than the Km value for hydrogen peroxide. Thus, the SBT liver GPX has a considerably greater affinity for hydrogen peroxide than for the other two substrates. The pH optimum of the purified enzyme was pH 8.0. Immunoblotting experiments with polyclonal antibodies, raised against a recombinant human GPX, provided further evidence that the purified SBT enzyme is a genuine GPX.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology - Volume 144, Issue 1, May 2006, Pages 86-93
نویسندگان
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