Research Specifications
- Full Name:
- Long R3 Insulin-like Growth Factor-1
- Modification:
- 13 aa N-terminal extension + Arg3→Glu3 substitution
- Molecular Weight:
- ~9,117 Da
- Form:
- Lyophilized powder
- Purity:
- ≥98% (SDS-PAGE and HPLC verified)
- Storage:
- −80°C ideal; −20°C acceptable; 4°C up to 7 days reconstituted
- Reconstitution:
- 0.1% acetic acid or bacteriostatic water with 0.1% BSA
IGF-1 LR3 1mg
Long Arg3 IGF-1 — extended half-life (20–30 hours vs 12–15 minutes for native IGF-1) insulin-like growth factor analog. IGFBP-independent. Researched for satellite cell activation and muscle protein synthesis.
IGF-1 Receptor Agonism & IGFBP Independence
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1, CAS: 946870-92-4) is a recombinant analog of native IGF-1 with two structural modifications: an N-terminal 13-amino acid extension and an Arg substitution at position 3 (replacing glutamic acid). These modifications reduce IGFBP (IGF binding protein) affinity by >1000-fold. Native IGF-1 is >99% bound to IGFBPs in circulation, limiting bioavailability and producing a 12–15 minute half-life. IGF-1 LR3 remains in free, active form with a half-life of approximately 20–30 hours — a 100x increase. It activates the IGF-1 receptor (IGF-1R), a receptor tyrosine kinase, driving the PI3K/Akt/mTOR pathway (protein synthesis, cell growth, survival) and Ras/MAPK pathway (proliferation, differentiation). IGF-1R is expressed on virtually every cell type. Molecular weight: ~9,117 Da.
Research Highlights
IGFBP Independence
The defining feature of IGF-1 LR3 is its near-complete independence from IGF binding proteins. Native IGF-1 is >99% bound to IGFBPs in circulation. IGF-1 LR3's position 3 arginine substitution reduces IGFBP-3 binding affinity by >1000-fold, allowing the analog to remain in free, active form — enabling research on unrestrained IGF-1R signaling.
Satellite Cell Activation
IGF-1 is the primary activator of muscle satellite cells — the stem cell population responsible for muscle regeneration and hypertrophy. Satellite cells express IGF-1R and respond to IGF-1 by exiting quiescence, proliferating, and differentiating into myoblasts. IGF-1 LR3's extended half-life makes it the practical choice for sustained satellite cell activation studies.
PI3K/Akt/mTOR Pathway
IGF-1R activation drives the PI3K/Akt/mTOR signaling cascade — the central anabolic pathway in mammalian biology. mTORC1 activation downstream of Akt stimulates protein synthesis via S6K1 and 4E-BP1, promotes ribosome biogenesis, and inhibits autophagy. IGF-1 LR3's extended activity window enables sustained mTOR pathway studies.
Research FAQ
What makes IGF-1 LR3 different from regular IGF-1?
What tissue types has IGF-1 LR3 been studied in?
How should IGF-1 LR3 be reconstituted?
Research Use Only. This product is intended for in-vitro laboratory research only. Not for human consumption, injection, or therapeutic use. Not medical advice. Always consult applicable regulations in your jurisdiction.
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IGF-1 LR3 1mg
$79.99