Anti-ErbB-3/HER3 Antibody, clone NG33

Receptor tyrosine-protein kinase erbB-3 (UniProt: P21860; also known as EC:2.7.10.1, Proto-oncogene-like protein c-ErbB-3, Tyrosine kinase-type cell surface receptor HER3) is encoded by the ERBB3 (also known as HER3) gene (Gene ID: 2065) in human. ErbB3 is a single-pass type I membrane glycoprotein that is synthesized with a signal peptide (aa 1-19), which is subsequently cleaved off to generate the mature form that contains an extracellular domain (aa 20-643), a transmembrane domain (aa 644-664), and a cytoplasmic domain (aa 665-1342). Its extracellular domain is formed of two ligand-binding regions (L1 and L2) and two cysteine-rich regions (CR1 and CR2). In the absence of a ligand, the extracellular domain stays in a locked conformation and is stabilized by interactions between CR1 and CR2 regions that prevent its dimerization. Its tyrosine kinase domain is localized to amino acids 709-966 and shares homology with EGFR and ErbB2 kinase domain. However, the tyrosine kinase activity is impaired due to modified residues and its activation requires the formation of heterodimers with other EGFR family receptors. Known ligands for ErbB3 include neuregulins (NRG) and NRG1 and NRG2 appear to be the most active. Downstream signaling pathways activated include MAPK and PI3 Kinase pathways. ErbB3 has been implicated in cell division and survival and its expression is essential for cell proliferation in several tumor models and transformation of normal tissues. It has also been implicated in acquired resistance to EGFR-tyrosine kinase inhibitors. Clone NG33 is shown to compete with NRG for binding to ErbB3/HER3 and inhibits NRG-induced migration and proliferation of cancer cells. It is reported to induce faster, and more extensive receptor degradation compared to NRG. (Ref.: Kiavue, N., et al. (2020). Oncogene. 39(3); 487-502; Gaborit, N., et al. (2015). Proc. Natl. Acad. Sci. USA. 112(3); 839-844).

A recombinant fragment corresponding to the extracellular domain of human ErbB-3/HER3 combined with the Fc domain of human IgG1.

Quality Control Testing

Evaluated by ELISA with recombinant Human ErRB-3/HER3 protein.

ELISA Analysis: Various dilutions of this antibody detected full-length recombinant Human ErbB-3/HER3 protein.

Tested Applications

Inhibition Assay: A representative lot of this antibody inhibited neuregulin (NRG)-induced migration and proliferation of cancer cells. (Gaborit, N., et al. (2015). Proc Natl Acad Sci USA. 112(3):839-44).

Flow Cytometry Analysis: A representative lot detected ErbB-3/HER3 in Flow Cytometry application (Gaborit, N., et al. (2015). Proc Natl Acad Sci USA. 112(3):839-44).

ELISA Analysis: A representative lot detected ErbB-3/HER3 in ELISA applications (Gaborit, N., et al. (2015). Proc Natl Acad Sci USA. 112(3):839-44).

Immunoprecipitation Analysis: A representative lot immunoprecipitated ErbB-3/HER3 in Immunoprecipitation application (Gaborit, N., et al. (2015). Proc Natl Acad Sci USA. 112(3):839-44).

Note: Actual optimal working dilutions must be determined by end user as specimens, and experimental conditions may vary with the end user.

Clone NG33 is a mouse monoclonal antibody that detects ErbB-3/HER3. It targets an epitope within the extracellular domain.

Purified mouse monoclonal antibody IgG1 in PBS without preservatives.

1.0 mg/mL. Please refer to guidance on suggested starting dilutions and/or titers per application and sample type.

Store at -10°C to -25°C. Handling Recommendations: Upon receipt and prior to removing the cap, centrifuge the vial and gently mix the solution. Aliquot into microcentrifuge tubes and store at -20°C. Avoid repeated freeze/thaw cycles, which may damage IgG and affect product performance.

Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.

Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.