کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1925475 | 1536387 | 2012 | 6 صفحه PDF | دانلود رایگان |
Recombinant heterotrimeric G-protein αi1, αi2 and αi3 subunits were purified in GDP-depleting conditions by affinity chromatography using StrepII-tagged β1γ2 subunits. Real-time monitoring of fluorescence anisotropy of Bodipy-FL-GTPγS was used for characterization of nucleotide binding properties and inactivation of the purified proteins. All GDP-depleted αi were unstable at room temperature and therefore nucleotide binding could be characterized only in a nonequilibrium state. In comparison to Mg2+, Mn2+ inhibited nucleotide binding to all αi-heterotrimers studied and accelerated nucleotide release. Mn2+ had stabilizing effect on the nucleotide free state of the αi1 subunit, whereas both Mn2+ as well as G-protein activation by mastoparan destabilized the αi2 subunit.
► StrepII-tagged γ2-subunits for the purification of heterotrimeric G-proteins.
► Preparation of GDP-depleted αi.
► Real-time monitoring of Bodipy-FL-GTPγS binding.
► Instability of GDP-depleted αi at room temperature.
► Mn2+ accelerates nucleotide release from Gα.
Journal: Archives of Biochemistry and Biophysics - Volume 524, Issue 2, 15 August 2012, Pages 93–98