Receptor tyrosine-protein kinase erbB-3, also known as HER3 (human epidermal growth factor receptor 3), is a membrane bound protein that in humans is encoded by the ERBB3 gene. ErbB3 has been shown to bind the ligands heregulin and NRG-2. Ligand binding causes a change in conformation that allows for dimerization, phosphorylation, and activation of signal transduction. ErbB3 can heterodimerize with any of the other three ErbB family members. The theoretical ErbB3 homodimer would be non-functional because the kinase-impaired protein requires transphosporylation by its binding partner to be active. Unlike the other ErbB receptor tyrosine kinase family members which are activated through autophosphorylation upon ligand binding, ErbB3 is found to be kinase impaired, having only 1/1000th the autophosphorylation activity of EGFR and no ability to phosphorylate other proteins. Therefore, ErbB3 must act as anallosteric activator. Sample Type: Cell culture supernates, serum and plasma (heparin, EDTA) Intended Use: For quantitative detection of human ERBB3 in cell culture supernates, serum and plasma (heparin, EDTA). Sensitivity: <10pg/ml Range: 156-10,000pg/ml Specificity: Natural and recombinant human ERBB3 Test Principle: This human ERBB3 BioAssay(TM) ELISA Kit was based on standard sandwich enzyme-linked immune-sorbent assay technology. A monoclonal antibody from mouse specific for ERBB3 has been precoated onto 96-well plates. Standards (NSO, S20-T643) and test samples are added to the wells, a biotinylated detection polyclonal antibody from goat specific for ERBB3 is added subsequently and then followed by washing with PBS or TBS buffer. Avidin-Biotin-Peroxidase Complex was added and unbound conjugates were washed away with PBS or TBS buffer. HRP substrate TMB was used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the human ERBB3 amount of sample captured in plate. Kit Components: 96-well plate precoated with human ERBB3 antibody, 1 Lyophilized recombinant human ERBB3 standard, 10ng/tube*2 Biotinylated human ERBB3 antibody, 130ul (dilution 1:100) Avidin-Biotin-Peroxidase Complex (ABC), 130ul (dilution 1:100) Sample diluent buffer, 30,ml Antibody diluent buffer, 12ml ABC diluent buffer, 12ml TMB color developing agent, 10ml TMB stop solution, 10ml Storage and Stability: Store powder at 4C liquid at -20C. Store other components at 4C. Stable for at least 6 months For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
