rhEGFRvIII Fc Avi Bi (50 ug)

Background: EGFR

Epidermal growth factor receptor (EGFR), also known as HER-1 and ErbB1, is a member of a subfamily of receptor tyrosine kinases comprised of four members: EGFR, ErbB2 (Neu, HER-2), ErbB3 (HER-3), and ErbB4 (HER-4). All family members are type I transmembrane glycoproteins with an extracellular domain (ECD) containing two cysteine-rich domains separated by a spacer region and a cytoplasmic domain containing a tyrosine kinase domain followed by multiple tyrosine autophosphorylation sites (1, 2). Several soluble isoforms lacking the intracellular domain are generated by alternate splicing (3‑4). EGFRvIII is a tumor‐specific mutation that results from an in‐frame deletion removing 267 amino acids from the ECD and insertion of a glycine residue (5). EGFRvIII has a molecular mass of approximately 145 kDa and has been shown to have weaker activity than full-length EGFR (6). EGFR binds a subset of the EGF family ligands, including EGF, amphiregulin, TGF-alpha, betacellulin, epiregulin, HB-EGF, and epigen (1, 2). Ligand binding induces EGFR homodimerization as well as heterodimerization with ErbB2, resulting in kinase activation, heterodimerization tyrosine phosphorylation and cell signaling (7‑9). EGFR can also be recruited to form heterodimers with the ligand‑activated ErbB3 or ErbB4. EGFR signaling regulates multiple biological functions including cell proliferation, differentiation, motility, and apoptosis (7-9). EGFR is overexpressed in a wide variety of tumors, with EGFRvIII overexpressed particularly in glioblastoma multiforme (GMB), and is the target of several anti-cancer therapeutics (5,10,11). Our Avi-tag Biotinylated Recombinant Human EGFRvIII features biotinylation at a single site contained within the Avi-tag, a unique 15 amino acid peptide. Protein orientation will be uniform when bound to streptavidin-coated surface due to the precise control of biotinylation and the rest of the protein is unchanged so there is no interference in the protein's bioactivity.