Cell Signaling Technology

Product Pathways - Growth Factors/Cytokines

Human Insulin-like Growth Factor I (hIGF-I) #8917

Request pricing for multi-milligram amounts.

Source

Recombinant human IGF-I (hIGF-I) Gly49-Ala118 (Accession #P01343) was produced in E. coli at Cell Signaling Technology.

Molecular Characterization

Recombinant hIGF-I has a Met on the amino terminus and has a calculated MW of 7,785. DTT-reduced and non-reduced protein migrate as 6 kDa polypeptides. The expected amino-terminal MGPET of recombinant hIGF-I was verified by amino acid sequencing.

Purity

>98% as determined by SDS-PAGE of 6 μg reduced (+) and non-reduced (-) recombinant hIGF-I. All lots are greater than 98% pure.

Bioactivity

The bioactivity of recombinant hIGF-I was determined in a cell proliferation assay using primary human dermal fibroblasts. The ED50 of each lot is between 2-8 ng/ml.

Coomassie Gel

Coomassie Gel

The purity of recombinant hIGF-I was determined by SDS-PAGE of 6 µg reduced (+) and non-reduced (-) recombinant hIGF-I and staining overnight with Coomassie Blue.

Bioactivity

Bioactivity

The proliferation of primary human dermal fibroblasts treated with increasing concentrations of hIGF-I was assessed. After 72-hour treatment with hIGF-I cells were incubated with a tetrazolium salt and the OD450 - OD650 was determined.

Western Blotting

Western Blotting

Western blot analysis of extracts from human dermal fibroblasts untreated or treated with hIGF-I for 10 minutes, using Phospho-Akt (Ser473) (D9E) XP® Rabbit mAb #4060 (upper) and Akt1 (C73H10) Rabbit mAb #2938 (lower).


Western Blotting

Western Blotting

Western blot analysis of extracts from MCF-7 cells, untreated or treated with hIGF-I for 10 minutes, using Phospho-Akt (Ser473) (D9E) XP® Rabbit mAb #4060 (upper) and Akt1 (C73H10) Rabbit mAb #2938 (lower).

Endotoxin

Less than 0.01 ng endotoxin/1 μg hIGF-I.

Formulation

With carrier: Lyophilized from a 0.22 μm filtered solution of 20 mM citrate, pH 3.0 containing 100 mM NaCl and 20 μg BSA per 1 μg hIGF-I. Carrier free: Lyophilized from a 0.22 μm filtered solution of 20 mM citrate, pH 3.0 containing 100 mM NaCl.

Background

Most circulating endocrine acting IGF-I is produced by hepatocytes, and paracrine or autocrine acting IGF-I is produced by defined cell types within specific tissues (1,2). Many neoplastic cells produce IGF-I, which regulates a number of cellular processes including energy metabolism, proliferation, and cell survival (3,4). IGF-I activity is regulated by one or more of the six extracellular IGF-binding proteins (IGFBPs). IGFBPs bind to IGF-I and most inhibit IGF-I binding to IGF-I receptor (IGFIR) (1,2). Some IGFBPs may increase cell responses to IGF-I. Binding of IGF-I to IGFIR activates the Akt, JNK, and Erk pathways (2). IGF-I and IGFIR are frequently expressed by cancer cells and may contribute to the proliferation and viability of a number of cancer types (1,2).

  1. Pollak, M. (2008) Nat Rev Cancer 8, 915-28.
  2. Chitnis, M.M. et al. (2008) Clin Cancer Res 14, 6364-70.
  3. Karey, K.P. and Sirbasku, D.A. (1988) Cancer Res 48, 4083-92.
  4. Small, T.W. and Pickering, J.G. (2009) J Biol Chem 284, 24684-95.

Application References

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products

This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

Products