Gαi Activation Assay Kit, 20 Assays (80301)

Product Highlight Configuration-specific monoclonal antibody that recognizes G _i -GTP, but not G _i -GDP The only available G _i activation assay kit directly measures the level of G _i -GTP Providing reliable results with consistent reproducibility than other G _i activation assay kits based on certain downstream signaling pathways Providing shorter experimental time Could be used to monitor the activation of G _i in cells and in tissues by immunohistochemistry Product Description A structurally diverse repertoire of ligands, from photons to large peptides, activates G protein-coupled receptors (GPCRs) to elicit their physiological functions. Ligand-bound GPCRs, in turn, function as guanine nucleotide exchange factors catalyzing the exchange of GDP bound on the G subunit with GTP in the presence of G, causing the dissociation of the G subunit from the G dimer to form two functional units (G and G). Both G and G subunits signal to various cellular signaling pathways. Based on the sequence and functional homologies, G proteins are grouped into four families: G _s , G _i , G _q , and G ₁₂ . G _i family is the largest family of G proteins. They relay signals from many GPCRs to regualte various biological functions. There were no direct methods to measure the activation of G _i proteins by receptors (until this assay kit). Most reports used one of the downstream pathway, i.e. the inhibition of adenylyl cyclases, as a readout. Alternatively, sensitivity to pertussis toxin (PTX) was used as an indicator of possible G _i proteins invovled in a signaling pathway. NewEast Biosciences G _i Activation Assay Kit provides a direct measurement of the activation of G _i proteins. This is a simple and fast tool to monitor the activation of G _i . Each kit provides sufficient quantities to perform 20 assays. NewEast Biosciences G _i Activation Assay Kit is based on the monoclonal antibody specifically recognizing the active GTP-bound G _i proteins. This monoclonal antibody has much lower affinity towards the inactive G _i proteins. Therefore, after activation by receptor signals, active GTP-bound G _i proteins could be immunoprecipitated by this monoclonal antibody and further quantified by western blot with another anti-G _i antibody. Assay Principle NewEast Biosciences G _i Activation Assay Kit is an immunoprecipitation/western blot assay to measure the levels of active GTP-bound G _i proteins, either from cell extracts or from in vitro GTPS loaded G _i proteins. Briefly, the anti-active G _i monoclonal antibody will specifically bind to active G _i protein. This antibody/G _i complex will then be pulled down by protein A/G agarose. The precipitated active G _i proteins will be detected by immunoblots with another anti-G _i antibody. Product Manual