Uses
Immunoprecipitation:
5 μg of a previous lot immunoprecipitated 100 ng of IGF-I.
Immunohistochemistry:
10 μg/mL of a previous lot was reported by an independent laboratory to detect IFG-I in formalin-fixed, paraffin-embedded skin sections.
(Lui, 1994).
Neutralization:
10-20 μg/mL of a previous lot inhibited the activity of 10 ng/mL of IGF-I as determined by testing with chicken embryo fibroblasts (CEF) using an ATP endpoint assay (ATPLiteTM-M, Packard Instruments).
General Description
Insulin-like growth factor 1 (IGF-1) is a polypeptide protein hormone similar in molecular structure to insulin. It plays an important role in childhood growth and continues to have anabolic effects in adults. IGF-1 consists of 70 amino acids in a single chain with three intramolecular disulfide bridges.
IGF-1 is produced primarily by the liver as an endocrine hormone and targets tissues in a paracrine/autocrine fashion. Production is stimulated by growth hormone and can be retarded by undernutrition, growth hormone insensitivity, lack of growth hormone receptors, or failures of the downstream signaling pathway post GH receptor including SHP2 and STAT5b. Approximately 98% of IGF-1 is always bound to one of 6 binding proteins (IGF-BP). IGFBP-3, the most abundant protein, accounts for 80% of all IGF binding. IGF-1 binds to IGFBP-3 in a 1:1 molar ratio. Its primary action is mediated by binding to specific IGF receptors present on many cell types in many tissues. The signal is transduced by intracellular events. IGF-1 is one of the most potent natural activators of the AKT signaling pathway, a stimulator of cell growth and multiplication and a potent inhibitor of programmed cell death.
