Delta-like 1, Recombinant, Human (DLL1, Delta1)

Delta-like protein 1 (DLL1) is a 90-100kD type I transmembrane protein that belongs to the Delta/Serrate/Lag-2 (DSL) family of Notch ligands. Mature human DLL1 consists of a 528 amino acid (aa) extracellular domain (ECD) with one DSL domain and eight EGF-like repeats, a 23 aa transmembrane segment, and a 155 aa cytoplasmic domain (1). Within the ECD, human DLL1 shares 91% aa sequence identity with mouse and rat DLL1. It shares 26%, 37%, and 54% aa sequence identity with DLL2, 3, and 4, respectively. A 60kD ECD fragment released by ADAM9, 12, or 17 mediated proteolysis, promotes the proliferation of hematopoietic progenitor cells (2, 3). The residual membrane-bound portion of DLL1 can be cleaved by presenilin-dependent gamma-secretase, enabling the cytoplasmic domain to migrate to the nucleus (4). DLL1 localizes to adherens junctions on neuronal processes through its association with the scaffolding protein MAGI1 (5). DLL1 is widely expressed, and it plays an important role in embryonic somite formation, cochlear hair cell differentiation, plus B and T lymphocyte differentiation (6-11). The upregulation of DLL1 in arterial endothelial cells following injury or angiogenic stimulation is central to postnatal arteriogenesis (12). DLL1 is also overexpressed in cervical carcinoma and glioma and contributes to tumor progression (1, 13). Product Description: Based on N-terminal amino acid sequencing, the recombinant human DLL1 expressed in NSO mouse myeloma cell line contains two forms of the protein: Ser 23-Gly540 and His152 -Gly540 (Accession # AAG09716), with calculated respective molecular masses of approximately 57 and 43 kDa. The recombinant human DLL1 migrates as approximately 66 and 55 kDa proteins in SDS-PAGE under reducing conditions. Each protein contains 6X histidine tag at the C-terminus via a peptide linker DI. Activity: Measured by the ability of immobilized protein to enhance BMP-2 induced alkaline phosphatase activity in MC3T3-E1 cells (Nobta M, et al. 2005. J. Biol. Chem. 280:15842). The ED50 for this effect is typically 0.25-1.0ug/ml. Storage and Stability: Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstituted sterile product is stable for 3 months at -20°C or lower. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.