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 ErbB3, His Tag (ER3-H5223) is expressed from human 293 cells (HEK293). It contains AA Ser 20 - Thr 643 (Accession # P21860-1).
Predicted N-terminus: Ser 20

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus.
The protein has a calculated MW of 70.5 kDa. The protein migrates as 90-100 kDa under reducing (R) condition (SDS-PAGE) due to 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
Please refer to product data sheet.

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