ED 50 < 20.0 ng/ml, measured by a cell proliferation assay using FDCP-1 cells, corresponding to a specific activity of > 5.0 × 10 4 units/mg.

IGF2/IGF-II Protein, Human, Recombinant (E. coli) is expressed in E. coli. The accession number is P01344-1.

Human

E. coli

Somatamedin A,Insulin-like Growth Factor-II

Ala25-Glu91

> 95% as determined by SDS-PAGE; > 95% as determined by HPLC

Reconstitute the lyophilized protein in sterile deionized water. The product concentration should not be less than 100 μg/ml. Before opening, centrifuge the tube to collect powder at the bottom. After adding the reconstitution buffer, avoid vortexing or pipetting for mixing.

Upon receiving, this product remains stable for up to 6 months at lower than -70°C. Upon reconstitution, the product should be stable for up to 1 week at 4°C or up to 3 months at -20°C. For long term storage it is recommended that a carrier protein (example 0.1% BSA) be added. Avoid repeated freeze-thaw cycles.

Insulin-like Growth Factor II (IGF-II) is a single chain 7 kDa polypeptide, and shares a high degree of homology with insulin. During circulation in vivo, IGF-II is complexed to high affinity binding proteins, IGF Binding Proteins (IGFBP), which act as circulating reservoirs, transport IGF-II, and prolong the half life of IGF-II. The receptors of IGF-II (IGFRs) are transmembrane tyrosine receptors, and are heterotetrameric consisting of two α-subunits and two β-subunits. IGFRs execute their role via intracellullar signaling molecules, such as IRS, shc, and PI3K. The functions of IGF-II include promoting cell survival, growth, proliferation, differentiation and motility. In particular, IGF-II promotes proliferation, inhibits death, and stimulates transformation in breast cancer cells.