IGF/LR3

IGF-1 LR3 (Long Arginine 3-Insulin-Like Growth Factor-1) is a synthetic 83-amino acid analogue of human IGF-1, engineered with two key modifications: an arginine substitution at position 3 (replacing glutamic acid) and a 13-amino acid N-terminal extension. These changes significantly reduce its binding affinity to IGF-binding proteins (IGFBPs 1 through 6), extending its functional activity in experimental systems. IGF-1 LR3 activates the IGF-1 receptor (IGF-1R) and initiates downstream signaling through the PI3K/Akt and MAPK/ERK pathways. It is approximately three times more potent than native IGF-1 in cell-based assays and possesses a substantially longer half-life. It is widely used in cell culture models studying proliferation, differentiation, and survival signaling across multiple tissue types. For research use only. Not for human consumption.

Chemical Structure and Identification

• Molecular Formula: C₄₀₀H₆₂₅N₁₁₁O₁₁₅S₉
• Molecular Weight: 9117.5 g/mol
• CAS Number: 946870-92-4

Research Applications

• Muscle and Connective Tissue Signaling: Investigation of IGF-1R-mediated proliferation, differentiation, and survival pathways in skeletal muscle, chondrocyte, and fibroblast cell models [1]
• Stem Cell and Regenerative Research: Study of LR3-IGF-1’s role in supporting lineage differentiation of mesenchymal and neural stem cells via PI3K/Akt and mTOR pathway activation [2]
• Cancer Cell Biology: Examination of IGF-1R-driven signaling in tumor cell proliferation, resistance mechanisms, and metabolic reprogramming models [3]
• Comparative IGF Pharmacology: Use of IGF-1 LR3 as a high-potency reference analogue in receptor binding affinity and downstream signaling comparison studies [4]

Reference Citations

1. Tomas FM et al. (1996) – J Endocrinol | https://pubmed.ncbi.nlm.nih.gov/8708565/
2. Cohick WS et al. (1993) – Annu Rev Physiol | https://pubmed.ncbi.nlm.nih.gov/8460085/
3. Denduluri SK et al. (2015) – Genes Dis | https://pmc.ncbi.nlm.nih.gov/articles/PMC4874159/
4. Baserga R et al. (1995) – Cell | https://pubmed.ncbi.nlm.nih.gov/7600989/

Important Regulatory Notice

These products are for research use only and are not intended for human consumption, therapeutic use, or diagnostic purposes. All compounds described herein have not been approved by the FDA for human use. These products are strictly intended for in vitro laboratory research and analytical purposes when conducted by qualified research professionals in licensed facilities. Users are responsible for ensuring compliance with all applicable laws regarding purchase and use of these materials.