Technical Data
Insulin-Like Growth Factor I Receptor, Recombinant, Mouse (IGF-I Receptor, IGFIR, IGFR, Insulin-like Growth Factor 1 Receptor, IGF1R, CD221, JTK13, MGC18216, MGC142170, MGC142172)
Molecular Biology Storage: -20CShipping: Blue Ice
The insulin-like growth factor I receptor (IGF-I R or IGF1R, designated CD221) is a 450kD disulfide-linked heterotetrameric transmembrane glycoprotein consisting of two 130kD a and two 95kD b subunits (1, 4). The IGF-1 R cDNA encodes a preproreceptor that is proteolytically cleaved to produce the extracellular a subunit (aa31-737), which contains a cysteine-rich region and two ligand-binding fibronectin type III (FN-III) domains, and the b subunit (aa742-1369), which contains an extracellular FN-III domain, transmembrane and cytoplasmic tyrosine kinase domains (1). Extracellular portions of mature mouse IGF-I R share 99.7% aa identity with rat, 96% with human, canine and porcine, and 95% with bovine and equine IGF-I R. IGF-I R is expressed in all cell types and tissues. It binds insulin-like growth factor I (IGF- I) with high affinity, IGF-II with lower affinity, and insulin with lowest affinity (2, 3). Both IGF-I R and the structurally similar insulin receptor (Ins R) activate the same signaling pathways in response to their respective ligands (3). IGF-I R/Ins R hybrids are formed in proportion to their expression and respond primarily to IGF-I, probably down-regulating cellular response to insulin (2, 5). IGF signaling is also modulated by IGF binding proteins and the scavenger receptor, IGF-II R (4). Expression or glycosylation of IGF-I R may be altered in cancer cells (4, 5). Mice lacking IGF-I R show intrauterine growth deficiency and die at birth due to respiratory failure, and IGF-I R mutations in humans can retarded pre- and postnatal growth (6-8). IGF-I and its receptor are particularly important for neurogenesis, with deficiency producing microcephaly and learning disorders (9 -11). Low expression of IGF-I R enhances lifespan in both mouse and human by increasing resistance to oxidative stress (12, 13). IGF-I R expression in human embryonic stem cells is important for their survival and clonogenicity (14).

Recombinant corresponding to aa1-93 of mouse IGF-IR, fused with 6-His tag at C-terminal, expressed with CHO cells.

Molecular Weight:
~104.5kD (single chain) 80.7kD (a subunit) 23.2 kD (b subunit)

Endotoxin Level:
1EU/1ug (LAL)

Biological Activity:
Measured by its binding ability in a functional ELISA. When rmIGF-IR is present at 0.5ug/ml, the concentration of rmIGF-I that produces 50% of the optimal binding response is found to be ~25-100ng/ml.

Storage and Stability:
Lyophilized powder may be stored at -20C. Stable for 12 months at -20C. Reconstitute with PBS. Aliquot to avoid repeated freezing and thawing. Store at -20C. Reconstituted product is stable for 6 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

Molecular Weight:
~104.5, 80.7, 23.2kD
Source: CHO
Purity: ~95% (SDS-PAGE)
Concentration: Not determined
Form: Supplied as a lyophilized powder in PBS. Reconstitute with PBS to 100ug/ml.

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
1. Wada, J. et al. (1993) Proc. Natl. Acad. Sci. USA 90:10360. 2. Slaaby, R. et al. (2006) J. Biol. Sci. 281:25869. 3. Boucher, J. et al. (2010) J. Biol. Chem. 285:17235. 4. Samani, A.A. et al. (2007) Endocr. Rev. 28:20. 5. Chitnis, M.M. et al. (2008) Clin. Cancer Res. 14:6364. 6. Liu, J-P. et al. (1993) Cell 75:59. 7. Abuzzahab, M.J. et al. (2003) N. Engl. J. Med. 349:2211. 8. Walenkamp, M.J.E. and J.M. Wit (2007) Eur. J. Endocrinol. 157:S15. 9. DErcole, A.J. et al. (2008) Endocrinology 149:5958. 10. Annenkov, A. (2009) Mol. Neurobiol. 40:195. 11. Mason, J.L. et al. (2003) J. Neurosci. 23:7710. 12. Holzenberger, M. et al. (2003) Nature 421:182. 13. Suh, Y. et al. (2008) Proc. Natl. Acad. Sci. USA 105:3438. 14. Bendall, S.C. et al. (2007) Nature 448:1015.

Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.