DDR2, also known as discoidin domain-containing receptor 2, belongs to the discoidin-like domain containing subfamily of receptor tyrosine kinases. It is mainly expressed in mesenchymal cells and is unique amog RTKs in that its ligand is fibrillar collagen rather than a growth factor-like peptide. Source: Recombinant protein corresponding to aa22-399 from human DDR2, fused to His-Tag at C-terminal, expressed in insect cell. Molecular Weight: ~43.7kD (386aa) 40-57KD (SDS-PAGE under reducing conditions.) Endotoxin: ~1EU/1ug (LAL) Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.