Figure 5.
Electrophoretic assay for RGS GTPase accelerating activity and its inhibition. (left) Basal hydrolysis by Gα alone results in formation of BGDP from BGTP; (middle) RGS protein accelerates the GTPase activity of Gα resulting in a larger BGDP peak formation; (right) addition of an inhibitor interferes with RGS and Gα interaction and thus diminishes the acceleratory effect of RGS protein resulting in a smaller BGDP peak in the electropherogram. All solutions were incubated for 20 min and then quenched with 10 μM GTPγS before electrophoretic analysis.