کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
20088 43157 2016 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Cloning and characterization of GST fusion tag stabilized large subunit of Escherichia coli acetohydroxyacid synthase I
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Cloning and characterization of GST fusion tag stabilized large subunit of Escherichia coli acetohydroxyacid synthase I
چکیده انگلیسی

There are three acetohydroxyacid synthase (AHAS, EC 4.1.3.18) isozymes (I, II, and III) in the enterobacteria Escherichia coli among which AHAS I is the most active. Its large subunit (LSU) possesses full catalytic machinery, but is unstable in the absence of the small subunit (SSU). To get applicable LSU of AHAS I, we prepared and characterized in this study the polypeptide as a His-tagged (His-LSU) and a glutathione S-transferase (GST)-tagged (GST-LSU) fusion protein, respectively. The results showed that the His-LSU is unstable, whereas the GST-LSU displays excellent stability. This phenomenon suggests that the GST polypeptide fusion tag could stabilize the target protein when compared with histidine tag. It is the first time that the stabilizing effect of the GST tag was observed. Further characterization of the GST-LSU protein indicated that it possesses the basic functions of AHAS I with a specific activity of 20.8 μmol min−1 mg−1 and a Km value for pyruvate of 0.95 mM. These observations imply that introduction of the GST fusion tag to LSU of AHAS I does not affect the function of the protein. The possible reasons that the GST fusion tag could make the LSU stable are initially discussed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Bioscience and Bioengineering - Volume 121, Issue 1, January 2016, Pages 21–26
نویسندگان
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