IGF1-LR3

IGF1-LR3 is an engineered analog of insulin-like growth factor 1. Two changes separate it from the native 70-amino-acid protein: arginine replaces glutamic acid at position 3, and a 13-residue extension is added to the N-terminus, giving an 83-amino-acid chain. Both modifications lower affinity for the IGF binding proteins that normally sequester native IGF-1 — which is precisely the point of the analog in a research setting, since it shifts the free-versus-bound equilibrium that confounds so many IGF experiments.

Produced by recombinant expression and shipped as a lyophilized powder in a sealed 1 mg glass vial. Supplied for laboratory research use only.

The analog exists to answer a methodological problem, and most of its literature reflects that. Areas of study include:

• IGFBP interaction — comparative binding of the modified and native sequences to the six IGF binding proteins.
• IGF-1 receptor engagement and downstream PI3K/Akt and MAPK signaling in cell culture.
• Receptor cross-talk with the insulin receptor and hybrid receptor forms, where selectivity is a persistent question.
• Use as a defined media component in serum-free cell culture, where a binding-protein-resistant growth factor gives more reproducible conditions.
• Protein stability in solution and across freeze-thaw.

Supplied as a laboratory reagent. We make no claim about effects in any organism.