IGF-1 LR3 (1mg)

What is IGF‑1 LR3 (Long Arg3 Insulin-like Growth Factor 1)?

IGF‑1 LR3 is a recombinant analogue of human insulin-like growth factor‑1, engineered to improve metabolic stability, receptor potency, and reduce affinity for IGF-binding proteins (IGFBPs). It contains the full 70-residue native IGF‑1 sequence with two key modifications: an arginine substitution at position 3 (Arg3), and a 13-amino-acid N-terminal extension, which together enhance biological half-life and potency in research studies.

Chemical Structure of IGF‑1 LR3

IGF‑1 LR3 is an 83-amino-acid polypeptide with the sequence:

MFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA

Key features include the Arg3 substitution and a 13-residue N-terminal extension. Its molecular formula is C₄₀₀H₆₂₅N₁₁₁O₁₁₅S₉, and molecular weight is approximately 9,117 Da.

What Are the Effects of IGF‑1 LR3?

• Enhanced Anabolic and Mitogenic Activity: IGF‑1 LR3 demonstrates approximately 3× greater receptor potency than native IGF‑1 and sustains signaling through PI3K/Akt and MAPK pathways due to lower IGFBP binding and extended half-life (~20–30 hours).
• Cell Proliferation and Protein Synthesis: Promotes cell division, nitrogen retention, protein synthesis, and lean tissue mass accumulation in animal models.
• Tissue Regenerative Research: Used in muscle, cartilage, nerve, liver, and skin regeneration models, where it enhances nutrient uptake and supports anabolic repair processes.
• Metabolic Modulation: Facilitates glucose and amino acid uptake while improving insulin sensitivity under metabolic stress conditions.
• Atherosclerotic Plaque Stability: Helps stabilize atherosclerotic plaques by improving vascular smooth muscle phenotype and reducing plaque vulnerability.

Citations

1. PubChem Compound Summary – IGF‑1 LR3: molecular structure, Arg3 substitution, and formula Overview of IGF‑1 LR3
2. Tomas FM, et al. “IGF‑I analogues show greater potency and prolonged effects.” J Endocrinol Overview of IGF‑1 LR3
3. von der Thüsen JH, et al. “IGF‑1 enhances plaque stability in atherosclerosis.” Am J Pathol Overview of IGF‑1 LR3
4. Mohan S, Baylink DJ. “IGF‑binding proteins and regulation of IGF activity.” J Endocrinol Overview of IGF‑1 LR3
5. Tomas FM, Knowles SE, et al. “Anabolic effects of IGF‑I variants in rat models.” Biochem J Overview of IGF‑1 LR3