The epidermal growth factor receptor (EGF R) subfamily of receptor tyrosine kinases comprises four members: EGF R (also known as HER1, ErbB1 or ErbB), ErbB2 (Neu, HER-2), ErbB3 (HER-3), and ErbB4 (HER-4). All family members are type I transmembrane glycoprotein that has an extracellular domain which contains two cysteine-rich domains separated by a spacer region that is involved in ligand-binding, and a cytoplasmic domain which has a membrane-proximal tyrosine kinase domain and a C-terminal tail with multiple tyrosine autophosphorylation sites. The human EGF R gene encodes a 1210 amino acid (aa) residue precursor with a 24 aa putative signal peptide, a 621 aa extracellular domain, a 23 aa transmembrane domain, and a 542 aa cytoplasmic domain. EGF R has been shown to bind a subset of the EGF family ligands, including EGF, amphiregulin, TGF-a , betacellulin, epiregulin, heparin-binding EGF and neuregulin-2 in the absence of a co-receptor. Ligand binding induces EGF R homodimerization as well as heterdimerization with ErbB2, resulting in kinase activation, tyrosine phosphorylation and cell signaling. EGF R can also be recruited to form heterodimers with the ligand-activated ErbB3 or ErbB4. EGF R signaling has been shown to regulate multiple biological functions including cell proliferation, differentiation, motility and apoptosis. In addition, EGF R signaling has also been shown to play a role in carcinogenesis.
DESCRIPTION
The EGFR contains the extracellular domain of the human EGFR (25-647 a.a.) excluding the signal peptide which is cleaved by the insect cells having an approximate Mw of 85kDa. The EGFR is fused to a C-terminal Strep-tag and purified by proprietary chromatographic techniques.
SOURCE
Sf9 Insect Cells.
PHYSICAL APPEARANCE
Sterile Filtered White lyophilized (freeze-dried) powder.
FORMULATION
ErbB1 was lyophilized from a concentrated (1mg/ml) sterile solution containing 1x PBS pH-7.4.
SOLUBILITY
It is recommended to reconstitute the lyophilized EGFR in sterile PBS not less than 100µg/ml, which can then be further diluted to other aqueous solutions.
STABILITY
Lyophilized EGFR although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution EGFR should be stored at 4°C between 2-7 days and for future use below -18°C.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please prevent freeze-thaw cycles.
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