کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
866062 909695 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of Urea on Activity and Conformation of a Glycoprotein
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
پیش نمایش صفحه اول مقاله
Effect of Urea on Activity and Conformation of a Glycoprotein
چکیده انگلیسی
The changes of the activity and conformation of Aspergillus niger phytase in urea were detected by far-ultraviolet circular dichroism (CD) spectra, fluorescence spectra, and enzyme activity assays. The results show that no enzyme activity can be detected after phytase is incubated for 10 h in 3.0 mol/L urea, even though at this urea concentration, less than 20% of the tertiary and secondary structures in the native enzyme changed. The inactivation reaction kinetics is found to be a monophasic first-order reaction, but the unfolding is a biphasic process consisting of two first-order reactions. The inactivation rates of the free enzyme and the substrate-enzyme complex are much faster than the conformational changes during urea denaturation. All of the results indicate that, as a glycoprotein, phytase's activity is strongly dependent on its conformational integrity. The phytase active sites seem to be located in a limited region in the molecule and display more conformational fragility and flexibility to denaturants than enzyme molecular structure as a whole.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tsinghua Science & Technology - Volume 11, Issue 4, August 2006, Pages 400-407
نویسندگان
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