Insulin-like growth factor I (IGF1) belongs to the family of insulin-like growth factors that are structurally homologous to proinsulin. Mature IGFs are generated by proteolytic processing of inactive precursor proteins; which contains the N- and C-terminal propeptide regions. Mature human IGF-I consisting of 70 amino acids has 94% identity with mouse IGF-I and exhibits cross-species activity. IGF-1 binds IGF-IR; IGF-IIR; and the insulin receptor and plays a key role in cell cycle progression; cell proliferation and tumor progression. IGF-1 expression is regulated by growth hormone. R3 IGF-1 is an 83 amino acid analog of IGF-1 comprising the complete human IGF-1 sequence with the substitution of an Arg (R) for the Glu(E) at position three; hence R3; and a 13 amino acid extension peptide at the N terminus. R3 IGF-1 has been produced with the purpose of increasing biological activity. R3 IGF-1 is significantly more potent than human IGF-I in vitro.
Measured in a serum-free cell proliferation assay using MCF?7 human breast cancer cells. The ED50 for this effect is 0.2-1.5 ng/ml.
Endotoxin:
<1.0 EU per µg as determined by the LAL method.
Protein Construction:
Recombinant Human LR3 Insulin-Like Growth Factor-I is produced by our E.coli expression system and the target gene encoding Gly49-Ala118 (Glu51Arg) is expressed.
Purity:
> 95 % as determined by reducing SDS-PAGE.
Mol Mass:
9.1 kDa
AP Mol Mass:
11 kDa
Formulation:
Lyophilized from a 0.2 µm filtered solution of 300mM HAc-NaAc; pH 6.5.
Shipping:
This product is provided as lyophilized powder which is shipped with ice packs.
Stability and Storage:
Lyophilized proteins are stable for up to 12 months when stored at -20 to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. Aliquots of reconstituted samples are stable at < -20°C for 3 months.
