کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9616762 | 48871 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Activation of subtilisin Carlsberg in hexane by lyophilization in the presence of fumed silica
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
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چکیده انگلیسی
Subtilisin Carlsberg (SC) was lyophilized from an aqueous buffer solution containing different amounts of unmodified commercial fumed silica. The activity of the enzyme/fumed silica preparation in hexane was compared to pure freeze-dried enzyme, and to a freeze-dried preparation reported in the literature with potassium chloride as additive. A sharp increase in enzyme activity was found to correlate with an increasing amount of fumed silica added to the enzyme solution prior to freeze-drying. A weight-ratio of 98.5 wt.% fumed silica relative to the mass of the final enzyme/fumed silica preparation led to about 130-fold increased activity of SC in hexane (when compared to pure lyophilized SC in hexane). This is about twice the activation effect compared to including potassium chloride in the buffer solution before freeze-drying [1]. When freezing at â20 °C instead of in liquid nitrogen, even better activation was observed with fumed silica. We hypothesize that the activation of SC in hexane by immobilization of the enzyme on fumed silica is likely due to the distribution of the enzyme on the large surface area of fumed silica. This alleviates mass transfer limitations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Catalysis B: Enzymatic - Volume 34, Issues 1â6, 1 July 2005, Pages 18-24
Journal: Journal of Molecular Catalysis B: Enzymatic - Volume 34, Issues 1â6, 1 July 2005, Pages 18-24
نویسندگان
Kerstin Würges, Peter H. Pfromm, Mary E. Rezac, Peter Czermak,