The PathScan® Multiplex Western Detection Cocktail offers a unique method to assay the inhibition of multiple proteins on one membrane without stripping and reprobing. This method saves the user valuable time while increasing accuracy and minimizing reagent waste. The Bcr/Abl Activity Assay allows the user to simultaneously detect the inhibition of phosphorylation of c-Abl, Stat5 and CrkL proteins in response to STI-571. The cocktail also includes Rab11 antibody to control protein loading.
Each phospho-antibody in this cocktail recognizes endogenous levels of only the phosphorylated form of its specific target. The Rab11 Antibody detects endogenous levels of its target protein independent of phosphorylation and is provided to control for protein loading.
Antibodies are produced by immunizing animals with synthetic peptides. Polyclonal antibodies are purfied by protein A and peptide affinity chromatography.
STI-571 (also known as Imatinib mesylate) is a tyrosine kinase (TK) inhibitor that is a relatively specific ATP-binding site antagonist of Bcr-Abl, PDGF receptor and c-Kit TKs (1-3). Results are encouraging in CML clinical trials, and STI-571 has become a paradigm for targeted cancer therapeutics (4-6). Signal transduction through phospho-tyrosine pathways has been studied extensively, and tyrosine phosphorylation has been linked to multiple cell growth and differentiation pathways (7-9). Because the observed leukemic state of CML is dependent on the intact Bcr-Abl tyrosine kinase activity, extensive work has been done to identify substrates of Bcr-Abl and thus possible mechanisms leading to a myeloid expansion. Many groups have characterized prominent tyrosine-phosphorylated protein substrates in both CML blasts and Bcr-Abl-expressing cell lines, including SHIP, c-cbl, Dok, SHC and CrkL (10-15). In addition, key signal transduction pathways involving PI3 kinase, Ras, Myc and Stat5 are also activated in a Bcr-Abl kinase-dependent manner (16).
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc. PathScan is a trademark of Cell Signaling Technology, Inc.