Conformational changes induced by Mg2+ on the multiple forms of glutamine synthetase from Bacillus brevis Bb G1
Date
2013-09-12
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Publisher
Plovdiv University Press “Paisii Hilendarski”
Abstract
Conformational changes play an important role in the function of proteins. Glutamine synthetase, an important enzyme of nitrogen metabolism, was purified under sporulating (GSala) and non-sporulating (GSpyr) conditions and the effect of Mg2+ on these multiple forms was studied by fluorescence spectroscopy to detect possible conformational changes that occur in the presenceof Mg2+. The substantial changes in the fluorescence emission maximum, fluorescence intensity and lifetime that occur in the presence of different concentrations of Mg2+, indicated major changes in molecular conformations in both forms of this enzyme. The fluorescent changes produced by the effect of Mg2+ in GSala was much more prominent than in GSpyr. These observations strongly support the possibility that GSala and GSpyr undergoes a conformational change on binding with Mg2+.
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Keywords
glutamine synthetase, fluorescence spectroscopy, conformational changes