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
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
A surface plasmon resonance study of the intermolecular interaction between Escherichia coli topoisomerase I and pBAD/Thio supercoiled plasmid DNA
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 8 nM. We then studied the effect of Mg2+ on the catalysis of EctopoI-pBAD/Thio reaction. A slightly higher equilibrium dissociation constant (∼15 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 (∼0.043 s−1), compared to EctopoI-pBAD/Thio interactions (∼0.017 s−1). 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
نویسندگان
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