The SGP1 monoclonal antibody specifically recognizes human ErbB3 (also known as HER-3), a 160-kDa glycoprotein that is a member of the epidermal growth factor receptor or ErbB family of receptor tyrosine kinases. Other members of the family include the epidermal growth factor receptor (EGFR, ErbB-1, HER1), ErbB-2 (Neu, HER2), and ErbB-4 (HER4). Members of this receptor family mediate the proliferation and differentiation of normal cells. They have a common structure consisting of an extracellular ligand-binding domain, a transmembrane region, and a cytoplasmic region that has sequence homology to tyrosine kinases, which is inactive in ErbB3. ErbB3 is expressed on neurons and in tissues from the digestive, urinary and respiratory tracts, the circulatory system, and female and male reproductive organs. It is overexpressed in a variety of tumors and is undetectable in hematopoietic tissue and cell lines derived from hematopoietic tumors. ErbB3 is able to form heterodimers with other ErbB family members that have active tyrosine kinases. This interaction is able to mediate signal transduction upon binding of ErbB3 to its ligand neuregulin, a cell adhesion molecule that is involved in development of the heart and nervous system.
The antibody was conjugated to BD Horizon Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor® 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor® 700.