Insulin-Like Growth Factor I (IGF1), murine recombinant (rmIGF1)

A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on Somatotropin. It is believed to be mainly active in adults in contrast to Insulin like Growth Factor 2, which is a major fetal growth factor. Recombinant murine IGF-1 is a single, non-glycosylated, polypeptide chain containing 70 amino acids and having a molecular mass of 7.6kD. , Amino Acid Sequence:, The sequence of the first five N-terminal amino acids was determined and was found to be Gly-Pro-Glu-Thr-Leu. N-terminal methionine has been completely removed enzymatically. Biological Activity: IGF-I is fully biologically active when compared to standards. The ED50, calculated by the dose-dependant proliferation of murine BALB\C 3T3 cells (measured by 3H-thymidine uptake) is <1.0ng/ml, corresponding to a specific activity of 1x10e5 U/mg. Protein Content: Protein quantitation was carried out by two independent methods: , 1. UV spectroscopy at 280nm using the absorbency value of 0.47 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics). , 2. Analysis by RP-HPLC, using a standard solution of IGF-I as a Reference Standard. Storage and Stability: Lyophilized powder may be stored at 4°C for short-term only. Reconstitute to nominal volume by adding sterile ddH2O, 0.1% HSA or BSA and store at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Further dilutions can be made in assay buffer.