IGF-1 LR3: The Long R3 Recombinant Growth-Factor Analog

IGF-1 LR3 is a redesign with one goal: make insulin-like growth factor-1 last longer by reducing its interaction with the proteins that bind and sequester it. The result is a recombinant analog studied as a comparator and a growth-factor signaling tool.

The molecule

IGF-1 LR3 (Long R3 IGF-1, C₄₀₀H₆₂₅N₁₁₁O₁₁₅S, ≈ 9118 g/mol) is an 83-residue recombinant analog of human IGF-1 with two modifications: an arginine in place of glutamate at position 3, and a 13-residue N-terminal extension. Both changes reduce binding to IGF-binding proteins (IGFBPs), which in native IGF-1 is what controls its free fraction.

What the research looks at

• IGF-1 receptor signaling — PI3K/Akt and MAPK pathway studies
• Cell proliferation and differentiation — where IGF-1 receptor activation is the question
• IGFBP-interaction research — the analog’s reduced binding makes it a tool for studying what free IGF-1 does without sequestration

It sits downstream of growth-hormone signaling — see the HGH 191aa page for the upstream half of that axis.

Handling notes

Lyophilized, reconstitute with bacteriostatic water; the reconstitution calculator handles the math. Store at −20°C lyophilized.

See IGF-1 LR3 for CAS, purity and full specifications.

For laboratory research use only. Not medical advice.