کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10756101 | 1050381 | 2014 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A surface plasmon resonance study of the intermolecular interaction between Escherichia coli topoisomerase I and pBAD/Thio supercoiled plasmid DNA
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
To date, the bacterial DNA topoisomerases are one of the major target biomolecules for the discovery of new antibacterial drugs. DNA topoisomerase regulates the topological state of DNA, which is very important for replication, transcription and recombination. The relaxation of negatively supercoiled DNA is catalyzed by bacterial DNA topoisomerase I (topoI) and this reaction requires Mg2+. In this report, we first quantitatively studied the intermolecular interactions between Escherichia coli topoisomerase I (EctopoI) and pBAD/Thio supercoiled plasmid DNA using surface plasmon resonance (SPR) technique. The equilibrium dissociation constant (Kd) for EctopoI-pBAD/Thio interactions was determined to be about 8Â nM. We then studied the effect of Mg2+ on the catalysis of EctopoI-pBAD/Thio reaction. A slightly higher equilibrium dissociation constant (â¼15Â nM) was obtained for Mg2+ coordinated EctopoI (Mg2+EctopoI)-pBAD/Thio interactions. In addition, we observed a larger dissociation rate constant (kd) for Mg2+EctopoI-pBAD/Thio interactions (â¼0.043Â sâ1), compared to EctopoI-pBAD/Thio interactions (â¼0.017Â sâ1). These results suggest that enzyme turnover during plasmid DNA relaxation is enhanced due to the presence of Mg2+ and furthers the understanding of importance of the Mg2+ ion for bacterial topoisomerase I catalytic activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 445, Issue 2, 7 March 2014, Pages 445-450
Journal: Biochemical and Biophysical Research Communications - Volume 445, Issue 2, 7 March 2014, Pages 445-450
نویسندگان
Purushottam Babu Tiwari, Thirunavukkarasu Annamalai, Bokun Cheng, Gagandeep Narula, Xuewen Wang, Yuk-Ching Tse-Dinh, Jin He, Yesim Darici,