IGF-1 LR3

Third-Party Tested

Independent lab verified

Batch-Specific CoA

Publicly accessible

YPB.285

Reference number

0.1mg

Lyophilized vial

Origin

IGF-1 LR3 (Long Arg3 IGF-1) is a recombinant analog of human insulin-like growth factor 1. IGF-1 itself was first characterized by Rinderknecht and Humbel in 1978. The LR3 variant was engineered by Francis et al. at GroPep (Adelaide, Australia) in the 1990s with an N-terminal 13-amino-acid extension and an Arg3 substitution to reduce IGF binding protein (IGFBP) affinity.

Research Lineage

Francis GL et al. published the characterization of LR3-IGF-1 as a cell culture supplement with superior mitogenic activity compared to native IGF-1. The reduced IGFBP binding results in higher bioavailability in serum-containing media. It has become a standard reagent in cell culture, stem cell research, and growth factor signaling studies.

Mechanism of Action

IGF-1 LR3 binds to the IGF-1 receptor (IGF-1R) and activates the PI3K/Akt and MAPK/ERK signaling cascades, promoting cell proliferation and survival. The Arg3 substitution and N-terminal extension reduce binding to IGFBPs 1-6, resulting in a greater fraction of free (active) peptide in biological fluids compared to native IGF-1.

Structural Notes

83-amino-acid recombinant protein (70 aa of IGF-1 + 13 aa N-terminal extension). Glu3 replaced by Arg3. Molecular weight: ~9,111 Da.