Recombinant human ErbB-3 /HER3 Protein, His Tag, 100µg

Background
ErbB3, also known as Her3 (human epidermal growth factor receptor 3), is a member of the epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases. This membrane-bound glycoprotein has a neuregulin binding domain but has not an active kinase domain. It therefore can bind the ligand but cannot mediate the intracellular signal transduction through protein phosphorylation.
However, it does form heterodimers with ErbB2 or other EGFR members responsible for tyrosine phosphorylation to give a receptor complex and initiate the related pathway, which lead to cell proliferation or differentiation. Overexpression of this protein has been reported in numerous cancers, including prostate, bladder, and breast tumors. This protein has different isoforms derived from alternative splicing variants, and among which, the secreted isoform lacking the intermembrane region modulates the activity of membrane-bound form.[1-6]

Source
Recombinant human ErbB-3 /HER3 Protein (rhErbB3) Ser20-Thr643 (Accession # NP_001973.2) was produced in human 293 cells (HEK293)

Molecular Characterization
rhErbB3, fused with a C-terminal 6×his tag and has a calculated MW of 71.5 kDa after removal of signal peptide. The predicted N-terminal is Ser 20. Protein migrates as 100-110 kDa in reduced SDS-PAGE resulting from glycosylation.

Endotoxin
Less than 1.0 EU per μg of the rhErbB3 by the LAL method.

Purity
>95% as determined by SDS-PAGE.

Formulation
Refer to data sheet

Reconstitution
See Certificate of Analysis for details of reconstitution instruction and specific concentration.

Storage
Avoid repeated freeze-thaw cycles.
No activity loss was observed after storage at:
In lyophilized state for 1 year (4C-8C); After reconstitution under sterile conditions for 1 month (4C-8C) or 3 months (-20C to -70C).

Bioactivity
Immobilized Human ErbB3, His Tag (Cat. No. ER3-H5223) at 2 μg/mL (100 μL/well) can bind Human NRG1-beat 1 Protein with a linear range of 0.6-10 ng/mL (Routinely tested).

References

(1) Singer, E. etal., 2001, J. Biol. Chem. 276 (47): 44266–74
(2) Kraus,M.H.etal.,1989,Proc.Natl.Acad.Sci.86:9193-9197
(3) Carraway,K.L.etal.,1994,J.Biol.Chem.269:14303-14306
(4) Wallasch,C.etal.,1995,EMBO.J.14:4267-4275
(5) Alimandi,M.etal.,1995,Oncogene.10:1813-1821
(6) Gamett,D.C.etal.,1995,J.Biol.Chem.270:19022-19027