کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8335984 | 1540285 | 2011 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Biophysical characterization of Bacillus licheniformis and Escherichia coli γ-glutamyltranspeptidases: A comparative analysis
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The oligomeric states of Bacillus licheniformis and Escherichia coli γ-glutamyltranspeptidases (BlGGT and EcGGT) in solution have been investigated by analytical ultracentrifugation. The results showed that BlGGT has a sedimentation coefficient of 5.12 S, which can be transformed into an experimental molecular mass of approximately 62,680 Da. The monomeric conformation is conserved in EcGGT. SDS-PAGE analysis and cross-linking studies further proved that the autocatalytically processed BlGGT and EcGGT form a heterodimeric association. Unfolding analyses using circular dichroism and tryptophan emission fluorescence revealed that these two proteins had a different sensitivity towards temperature- and guanidine hydrochloride (GdnHCl)-induced denaturation. BlGGT and EcGGT had a Tm value of 59.5 and 49.2 °C, respectively, and thermal unfolding of both proteins was found to be highly irreversible. Chemical unfolding of BlGGT was independent to the pH value ranging from 5 to 10, whereas the pH environment was found to significantly influence the GdnHCl-induced denaturation of EcGGT. Both enzymes did not reactivate from the completely unfolded states, accessible at 6 M GdnHCl. BlGGT was active in the presence of 4 M NaCl, whereas the activity of EcGGT was significantly decreased at the high-salt condition. Taken together, these findings suggest that the biophysical properties of the homologous GGTs from two mesophilic sources are quite different.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 48, Issue 3, 1 April 2011, Pages 414-422
Journal: International Journal of Biological Macromolecules - Volume 48, Issue 3, 1 April 2011, Pages 414-422
نویسندگان
Jia-Ci Yang, Wan-Chi Liang, Yi-Yu Chen, Meng-Chun Chi, Huei-Fen Lo, Hsiang-Ling Chen, Long-Liu Lin,