Human CD340 (Receptor tyrosine-protein kinase erb2) gene encodes a member of the epidermal growth factor (EGF) receptor family of receptor tyrosine kinases. This protein has no ligand binding domain of its own and therefore cannot bind growth factors. However, it does bind tightly to other ligand-bound EGF receptor family members to form a heterodimer, stabilizing ligand binding and enhancing kinase-mediated activation of downstream signalling pathways, such as those involving mitogen-activated protein kinase and phosphatidylinositol-3 kinase. Allelic variations at amino acid positions 654 and 655 of isoform a (positions 624 and 625 of isoform b) have been reported, with the most common allele, Ile654/Ile655, shown here. Amplification and/or over-expression of this gene has been reported in numerous cancers, including breast and ovarian tumors. Alternative splicing results in several additional transcript variant.

Extracellular domain of human CD340 cDNA ( 23 – 652 aa. Isoform A ) was constructed with codon optimization using gene synthesis technology and expressed with a small T7-His-TEV cleavage site Tag (29aa) fusion at its N-terminal. This protein was expressed in E. coli as inclusion bodies. The final product was refolded using our unique “temperature shift inclusion body refolding” technology and chromatographically purified.

1. May be used for in vitro CD340 mediated PI3K pathway regulation study for various cancel cell with this protein either as soluble factor or as coating matrix protein.

2. May be used for protein-protein interaction mapping.

3. Potential biomarker/therapeutic protein for various cancer treatments by targeting CD340 with specific antibody derived drugs.

4. As immunogen for specific antibody production.