IGF-1 LR3

IGF-1 LR3 is a recombinant analog of insulin-like growth factor-1 with an arginine substitution at position 3 and a 13-residue N-terminal extension. It is supplied for cell-culture and laboratory research.

Research applications

IGF-1 LR3 is used in cell-culture work on proliferation, differentiation and survival signaling. Its altered binding to IGF binding proteins makes it a tool for comparing IGF-1 analog behavior in vitro. It also appears in muscle-cell and myostatin-signaling models. These are laboratory research uses.

Pathway and mechanistic context

Like IGF-1, the analog is described as acting through the IGF-1 receptor and, to a lesser degree, the insulin receptor. The literature reports weaker binding to IGF binding proteins than native IGF-1, which changes how long the analog stays active in culture. Studies in muscle-cell models have examined downstream signaling involving MyoD and the interaction with myostatin.

Preclinical summary

Mouse and cell-culture studies have examined IGF-1 and its derivatives for effects on myoblast survival, myostatin signaling and muscle-cell proliferation. Other animal work relates IGF-1 levels to lifespan and examines IGF-1 in glucocorticoid-related muscle models. These findings come from laboratory and animal models only.

Form and analytical testing

Supplied as a lyophilized powder. Identity and purity are normally confirmed by HPLC and mass spectrometry. Refer to the Certificate of Analysis for the lot you receive.

References

1. N. Li, Q. Yang, R. G. Walker, T. B. Thompson, M. Du, and B. D. Rodgers, "Myostatin Attenuation In Vivo Reduces Adiposity, but Activates Adipogenesis," Endocrinology, vol. 157, no. 1, pp. 282–291, Jan. 2016.
2. W. E. Sonntag, A. Csiszar, R. deCabo, L. Ferrucci, and Z. Ungvari, "Diverse roles of growth hormone and insulin-like growth factor-1 in mammalian aging: progress and controversies," J. Gerontol. A. Biol. Sci. Med. Sci., vol. 67, no. 6, pp. 587–598, Jun. 2012. Source
3. IGF-I/IGFBP system: metabolism outline and physical exercise. PubMed. Source
4. B. Y. Hanaoka, C. A. Peterson, C. Horbinski, and L. J. Crofford, "Implications of glucocorticoid therapy in idiopathic inflammatory myopathies," Nat. Rev. Rheumatol., vol. 8, no. 8, pp. 448–457, Aug. 2012.
5. A. Philippou, A. Halapas, M. Maridaki, M. Koutsilieris, J Musculoskelet Neuronal Interact, 2007. Source
6. A. Philippou, E. Papageorgiou, G. Bogdanis, A. Halapas et al., In vivo, 2009. Source

Peptides are shipped lyophilized (freeze-dried), a state that keeps them stable in transit. Keep vials cold and away from light on arrival.

• Short term: refrigeration below 4°C (39°F) is generally suitable for lyophilized material held for days to months.
• Long term: a freezer at -80°C (-112°F) is preferred for storage over several months or years.
• After reconstitution: keep the vial refrigerated. Reconstituted material is generally kept for up to 30 days.