کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1362267 981482 2006 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ribokinase from E. coli: Expression, purification, and substrate specificity
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Ribokinase from E. coli: Expression, purification, and substrate specificity
چکیده انگلیسی

Ribokinase (RK) was expressed in the Escherichia coli ER2566 cells harboring the constructed expression plasmid encompassing the rbsK gene, encoding ribokinase. The recombinant enzyme was purified from sonicated cells by double chromatography to afford a preparation that was ca. 90% pure and had specific activity of 75 μmol/min mg protein. Catalytic activity of RK: (i) is strongly dependent on the presence of monovalent cations (potassium ⋙ ammonium > cesium), and (ii) is cooperatively enhanced by divalent magnesium and manganese ions. Besides d-ribose and 2-deoxy-d-ribose, RK was found to catalyze the 5-O-phosphorylation of d-arabinose, d-xylose, and d-fructose in the presence of ATP, and potassium and magnesium ions; l-ribose and l-arabinose are not substrates for the recombinant enzyme. A new radiochemical method for monitoring the formation of d-pentofuranose-5-[32P]phosphates in the presence of [γ-32P]ATP and RK is reported.

Ribokinase (RK) was expressed in the Escherichia coli ER2566 cells, purified from sonicated cells by double chromatography to afford a preparation with specific activity of 75 μmol/min mg protein. Besides d-ribose and 2-deoxy-d-ribose, RK was found to catalyze the 5-O-phosphorylation of d-arabinose, d-xylose and d-fructose in the presence of ATP and potassium and magnesium ions; l-ribose and l-arabinose are not substrates for the recombinant enzyme. A new radiochemical method for monitoring the formation of d-ribofuranose-5-[32P]phosphate in the presence of [γ-32P]ATP and RK is reported.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Bioorganic & Medicinal Chemistry - Volume 14, Issue 18, 15 September 2006, Pages 6327–6332
نویسندگان
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